├── .github ├── FUNDING.yml └── workflows │ └── generate-playground.yml ├── .gitignore ├── CONTRIBUTING.md ├── Design-Patterns-CN.playground.zip ├── Design-Patterns-CN.playground ├── Pages │ ├── Behavioral.xcplaygroundpage │ │ └── Contents.swift │ ├── Creational.xcplaygroundpage │ │ └── Contents.swift │ ├── Index.xcplaygroundpage │ │ └── Contents.swift │ └── Structural.xcplaygroundpage │ │ ├── Contents.swift │ │ └── timeline.xctimeline └── contents.xcplayground ├── Design-Patterns.playground.zip ├── Design-Patterns.playground ├── Pages │ ├── Behavioral.xcplaygroundpage │ │ └── Contents.swift │ ├── Creational.xcplaygroundpage │ │ └── Contents.swift │ ├── Index.xcplaygroundpage │ │ └── Contents.swift │ └── Structural.xcplaygroundpage │ │ ├── Contents.swift │ │ └── timeline.xctimeline └── contents.xcplayground ├── LICENSE ├── PULL_REQUEST_TEMPLATE.md ├── README-CN.md ├── README.md ├── generate-playground-cn.sh ├── generate-playground.sh ├── source-cn ├── Index │ ├── header.md │ └── welcome.swift ├── behavioral │ ├── chain_of_responsibility.swift │ ├── command.swift │ ├── header.md │ ├── interpreter.swift │ ├── iterator.swift │ ├── mediator.swift │ ├── memento.swift │ ├── observer.swift │ ├── state.swift │ ├── strategy.swift │ ├── template_method.swift │ └── visitor.swift ├── contents.md ├── contentsReadme.md ├── creational │ ├── abstract_factory.swift │ ├── builder.swift │ ├── factory.swift │ ├── header.md │ ├── monostate.swift │ ├── prototype.swift │ └── singleton.swift ├── endComment ├── endSwiftCode ├── footer.md ├── imports.swift ├── startComment ├── startSwiftCode └── structural │ ├── adapter.swift │ ├── bridge.swift │ ├── composite.swift │ ├── decorator.swift │ ├── facade.swift │ ├── flyweight.swift │ ├── header.md │ ├── protection_proxy.swift │ └── virtual_proxy.swift └── source ├── Index ├── header.md └── welcome.swift ├── behavioral ├── chain_of_responsibility.swift ├── command.swift ├── header.md ├── interpreter.swift ├── iterator.swift ├── mediator.swift ├── memento.swift ├── observer.swift ├── state.swift ├── strategy.swift ├── template_method.swift └── visitor.swift ├── contents.md ├── contentsReadme.md ├── creational ├── abstract_factory.swift ├── builder.swift ├── factory.swift ├── header.md ├── monostate.swift ├── prototype.swift └── singleton.swift ├── endComment ├── endSwiftCode ├── footer.md ├── imports.swift ├── startComment ├── startSwiftCode └── structural ├── adapter.swift ├── bridge.swift ├── composite.swift ├── decorator.swift ├── facade.swift ├── flyweight.swift ├── header.md ├── protection_proxy.swift └── virtual_proxy.swift /.github/FUNDING.yml: -------------------------------------------------------------------------------- 1 | # These are supported funding model platforms 2 | 3 | github: ochococo 4 | -------------------------------------------------------------------------------- /.github/workflows/generate-playground.yml: -------------------------------------------------------------------------------- 1 | name: Generate Playground Files and READMES 2 | 3 | # Controls when the action will run. Triggers the workflow on push or pull request 4 | # events but only for the master branch 5 | on: 6 | push: 7 | branches: [master] 8 | 9 | # A workflow run is made up of one or more jobs that can run sequentially or in parallel 10 | jobs: 11 | # This workflow contains a single job called "build" 12 | generate-playgrounds: 13 | # The type of runner that the job will run on 14 | runs-on: macos-latest 15 | 16 | # Steps represent a sequence of tasks that will be executed as part of the job 17 | steps: 18 | # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it 19 | - uses: actions/checkout@v2 20 | 21 | # Checkout & Generate 22 | - name: Generate playgrounds and readmes 23 | run: | 24 | ./generate-playground.sh 25 | ./generate-playground-cn.sh 26 | 27 | # Commit 28 | - name: Commit files 29 | run: | 30 | git config --local user.email "action@github.com" 31 | git config --local user.name "GitHub Action" 32 | git add Design-Patterns-CN.playground.zip 33 | git add Design-Patterns.playground.zip 34 | git add README.md 35 | git add README-CN.md 36 | git commit -m "Generate Playground" 37 | ## Push changes to master branch 38 | - name: Push changes 39 | uses: ad-m/github-push-action@master 40 | with: 41 | github_token: ${{ secrets.GITHUB_TOKEN }} 42 | branch: "master" 43 | force: false 44 | 45 | # This workflow contains a single job called "build" 46 | generate-chinese-branch: 47 | needs: generate-playgrounds 48 | # The type of runner that the job will run on 49 | runs-on: macos-latest 50 | 51 | # Steps represent a sequence of tasks that will be executed as part of the job 52 | steps: 53 | # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it 54 | - uses: actions/checkout@v2 55 | 56 | # Checkout & Generate 57 | - name: Generate Chinese Readme 58 | run: | 59 | ./generate-playground-cn.sh 60 | mv ./README-CN.md ./README.md 61 | 62 | # Commit 63 | - name: Commit files 64 | run: | 65 | git config --local user.email "action@github.com" 66 | git config --local user.name "GitHub Action" 67 | git add README.md 68 | git commit -m "Generate Chinese version" 69 | ## Push changes to chinese branch 70 | - name: Push changes 71 | uses: ad-m/github-push-action@master 72 | with: 73 | github_token: ${{ secrets.GITHUB_TOKEN }} 74 | branch: "chinese" 75 | force: true 76 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | .DS_Store 2 | UserInterfaceState.xcuserstate 3 | playground.xcworkspace 4 | xcuserdata -------------------------------------------------------------------------------- /CONTRIBUTING.md: -------------------------------------------------------------------------------- 1 | How to contribute? 2 | ================== 3 | 4 | - You are awesome! 5 | - Only editing files inside `source` is recommended, the rest is autogenerated and translated 6 | - Run `generate-playground.sh` locally 7 | - Opene the .playground locally and check if it works 8 | - Please be patient and respectful to fellow contributors 9 | -------------------------------------------------------------------------------- /Design-Patterns-CN.playground.zip: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/evnaz/Design-Patterns-In-Swift/bd6dfaf9a241d418b3ec70a9faa275ffe279865e/Design-Patterns-CN.playground.zip -------------------------------------------------------------------------------- /Design-Patterns-CN.playground/Pages/Behavioral.xcplaygroundpage/Contents.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 3 | 行为型模式 4 | ======== 5 | 6 | >在软件工程中， 行为型模式为设计模式的一种类型，用来识别对象之间的常用交流模式并加以实现。如此，可在进行这些交流活动时增强弹性。 7 | > 8 | >**来源：** [维基百科](https://zh.wikipedia.org/wiki/%E8%A1%8C%E7%82%BA%E5%9E%8B%E6%A8%A1%E5%BC%8F) 9 | 10 | ## 目录 11 | 12 | * [行为型模式](Behavioral) 13 | * [创建型模式](Creational) 14 | * [结构型模式](Structural) 15 | */ 16 | import Foundation 17 | /*: 18 | 🐝 责任链（Chain Of Responsibility） 19 | ------------------------------ 20 | 21 | 责任链模式在面向对象程式设计里是一种软件设计模式，它包含了一些命令对象和一系列的处理对象。每一个处理对象决定它能处理哪些命令对象，它也知道如何将它不能处理的命令对象传递给该链中的下一个处理对象。 22 | 23 | ### 示例： 24 | */ 25 | 26 | protocol Withdrawing { 27 | func withdraw(amount: Int) -> Bool 28 | } 29 | 30 | final class MoneyPile: Withdrawing { 31 | 32 | let value: Int 33 | var quantity: Int 34 | var next: Withdrawing? 35 | 36 | init(value: Int, quantity: Int, next: Withdrawing?) { 37 | self.value = value 38 | self.quantity = quantity 39 | self.next = next 40 | } 41 | 42 | func withdraw(amount: Int) -> Bool { 43 | 44 | var amount = amount 45 | 46 | func canTakeSomeBill(want: Int) -> Bool { 47 | return (want / self.value) > 0 48 | } 49 | 50 | var quantity = self.quantity 51 | 52 | while canTakeSomeBill(want: amount) { 53 | 54 | if quantity == 0 { 55 | break 56 | } 57 | 58 | amount -= self.value 59 | quantity -= 1 60 | } 61 | 62 | guard amount > 0 else { 63 | return true 64 | } 65 | 66 | if let next = self.next { 67 | return next.withdraw(amount: amount) 68 | } 69 | 70 | return false 71 | } 72 | } 73 | 74 | final class ATM: Withdrawing { 75 | 76 | private var hundred: Withdrawing 77 | private var fifty: Withdrawing 78 | private var twenty: Withdrawing 79 | private var ten: Withdrawing 80 | 81 | private var startPile: Withdrawing { 82 | return self.hundred 83 | } 84 | 85 | init(hundred: Withdrawing, 86 | fifty: Withdrawing, 87 | twenty: Withdrawing, 88 | ten: Withdrawing) { 89 | 90 | self.hundred = hundred 91 | self.fifty = fifty 92 | self.twenty = twenty 93 | self.ten = ten 94 | } 95 | 96 | func withdraw(amount: Int) -> Bool { 97 | return startPile.withdraw(amount: amount) 98 | } 99 | } 100 | /*: 101 | ### 用法 102 | */ 103 | // 创建一系列的钱堆，并将其链接起来：10<20<50<100 104 | let ten = MoneyPile(value: 10, quantity: 6, next: nil) 105 | let twenty = MoneyPile(value: 20, quantity: 2, next: ten) 106 | let fifty = MoneyPile(value: 50, quantity: 2, next: twenty) 107 | let hundred = MoneyPile(value: 100, quantity: 1, next: fifty) 108 | 109 | // 创建 ATM 实例 110 | var atm = ATM(hundred: hundred, fifty: fifty, twenty: twenty, ten: ten) 111 | atm.withdraw(amount: 310) // Cannot because ATM has only 300 112 | atm.withdraw(amount: 100) // Can withdraw - 1x100 113 | /*: 114 | 👫 命令（Command） 115 | ------------ 116 | 命令模式是一种设计模式，它尝试以对象来代表实际行动。命令对象可以把行动(action) 及其参数封装起来，于是这些行动可以被： 117 | * 重复多次 118 | * 取消（如果该对象有实现的话） 119 | * 取消后又再重做 120 | ### 示例： 121 | */ 122 | protocol DoorCommand { 123 | func execute() -> String 124 | } 125 | 126 | final class OpenCommand: DoorCommand { 127 | let doors:String 128 | 129 | required init(doors: String) { 130 | self.doors = doors 131 | } 132 | 133 | func execute() -> String { 134 | return "Opened \(doors)" 135 | } 136 | } 137 | 138 | final class CloseCommand: DoorCommand { 139 | let doors:String 140 | 141 | required init(doors: String) { 142 | self.doors = doors 143 | } 144 | 145 | func execute() -> String { 146 | return "Closed \(doors)" 147 | } 148 | } 149 | 150 | final class HAL9000DoorsOperations { 151 | let openCommand: DoorCommand 152 | let closeCommand: DoorCommand 153 | 154 | init(doors: String) { 155 | self.openCommand = OpenCommand(doors:doors) 156 | self.closeCommand = CloseCommand(doors:doors) 157 | } 158 | 159 | func close() -> String { 160 | return closeCommand.execute() 161 | } 162 | 163 | func open() -> String { 164 | return openCommand.execute() 165 | } 166 | } 167 | /*: 168 | ### 用法 169 | */ 170 | let podBayDoors = "Pod Bay Doors" 171 | let doorModule = HAL9000DoorsOperations(doors:podBayDoors) 172 | 173 | doorModule.open() 174 | doorModule.close() 175 | /*: 176 | 🎶 解释器（Interpreter） 177 | ------------------ 178 | 179 | 给定一种语言，定义他的文法的一种表示，并定义一个解释器，该解释器使用该表示来解释语言中句子。 180 | 181 | ### 示例： 182 | */ 183 | 184 | protocol IntegerExpression { 185 | func evaluate(_ context: IntegerContext) -> Int 186 | func replace(character: Character, integerExpression: IntegerExpression) -> IntegerExpression 187 | func copied() -> IntegerExpression 188 | } 189 | 190 | final class IntegerContext { 191 | private var data: [Character:Int] = [:] 192 | 193 | func lookup(name: Character) -> Int { 194 | return self.data[name]! 195 | } 196 | 197 | func assign(expression: IntegerVariableExpression, value: Int) { 198 | self.data[expression.name] = value 199 | } 200 | } 201 | 202 | final class IntegerVariableExpression: IntegerExpression { 203 | let name: Character 204 | 205 | init(name: Character) { 206 | self.name = name 207 | } 208 | 209 | func evaluate(_ context: IntegerContext) -> Int { 210 | return context.lookup(name: self.name) 211 | } 212 | 213 | func replace(character name: Character, integerExpression: IntegerExpression) -> IntegerExpression { 214 | if name == self.name { 215 | return integerExpression.copied() 216 | } else { 217 | return IntegerVariableExpression(name: self.name) 218 | } 219 | } 220 | 221 | func copied() -> IntegerExpression { 222 | return IntegerVariableExpression(name: self.name) 223 | } 224 | } 225 | 226 | final class AddExpression: IntegerExpression { 227 | private var operand1: IntegerExpression 228 | private var operand2: IntegerExpression 229 | 230 | init(op1: IntegerExpression, op2: IntegerExpression) { 231 | self.operand1 = op1 232 | self.operand2 = op2 233 | } 234 | 235 | func evaluate(_ context: IntegerContext) -> Int { 236 | return self.operand1.evaluate(context) + self.operand2.evaluate(context) 237 | } 238 | 239 | func replace(character: Character, integerExpression: IntegerExpression) -> IntegerExpression { 240 | return AddExpression(op1: operand1.replace(character: character, integerExpression: integerExpression), 241 | op2: operand2.replace(character: character, integerExpression: integerExpression)) 242 | } 243 | 244 | func copied() -> IntegerExpression { 245 | return AddExpression(op1: self.operand1, op2: self.operand2) 246 | } 247 | } 248 | /*: 249 | ### 用法 250 | */ 251 | var context = IntegerContext() 252 | 253 | var a = IntegerVariableExpression(name: "A") 254 | var b = IntegerVariableExpression(name: "B") 255 | var c = IntegerVariableExpression(name: "C") 256 | 257 | var expression = AddExpression(op1: a, op2: AddExpression(op1: b, op2: c)) // a + (b + c) 258 | 259 | context.assign(expression: a, value: 2) 260 | context.assign(expression: b, value: 1) 261 | context.assign(expression: c, value: 3) 262 | 263 | var result = expression.evaluate(context) 264 | /*: 265 | 🍫 迭代器（Iterator） 266 | --------------- 267 | 268 | 迭代器模式可以让用户通过特定的接口巡访容器中的每一个元素而不用了解底层的实现。 269 | 270 | ### 示例： 271 | */ 272 | struct Novella { 273 | let name: String 274 | } 275 | 276 | struct Novellas { 277 | let novellas: [Novella] 278 | } 279 | 280 | struct NovellasIterator: IteratorProtocol { 281 | 282 | private var current = 0 283 | private let novellas: [Novella] 284 | 285 | init(novellas: [Novella]) { 286 | self.novellas = novellas 287 | } 288 | 289 | mutating func next() -> Novella? { 290 | defer { current += 1 } 291 | return novellas.count > current ? novellas[current] : nil 292 | } 293 | } 294 | 295 | extension Novellas: Sequence { 296 | func makeIterator() -> NovellasIterator { 297 | return NovellasIterator(novellas: novellas) 298 | } 299 | } 300 | /*: 301 | ### 用法 302 | */ 303 | let greatNovellas = Novellas(novellas: [Novella(name: "The Mist")] ) 304 | 305 | for novella in greatNovellas { 306 | print("I've read: \(novella)") 307 | } 308 | /*: 309 | 💐 中介者（Mediator） 310 | --------------- 311 | 312 | 用一个中介者对象封装一系列的对象交互，中介者使各对象不需要显示地相互作用，从而使耦合松散，而且可以独立地改变它们之间的交互。 313 | 314 | ### 示例： 315 | */ 316 | protocol Receiver { 317 | associatedtype MessageType 318 | func receive(message: MessageType) 319 | } 320 | 321 | protocol Sender { 322 | associatedtype MessageType 323 | associatedtype ReceiverType: Receiver 324 | 325 | var recipients: [ReceiverType] { get } 326 | 327 | func send(message: MessageType) 328 | } 329 | 330 | struct Programmer: Receiver { 331 | let name: String 332 | 333 | init(name: String) { 334 | self.name = name 335 | } 336 | 337 | func receive(message: String) { 338 | print("\(name) received: \(message)") 339 | } 340 | } 341 | 342 | final class MessageMediator: Sender { 343 | internal var recipients: [Programmer] = [] 344 | 345 | func add(recipient: Programmer) { 346 | recipients.append(recipient) 347 | } 348 | 349 | func send(message: String) { 350 | for recipient in recipients { 351 | recipient.receive(message: message) 352 | } 353 | } 354 | } 355 | 356 | /*: 357 | ### 用法 358 | */ 359 | func spamMonster(message: String, worker: MessageMediator) { 360 | worker.send(message: message) 361 | } 362 | 363 | let messagesMediator = MessageMediator() 364 | 365 | let user0 = Programmer(name: "Linus Torvalds") 366 | let user1 = Programmer(name: "Avadis 'Avie' Tevanian") 367 | messagesMediator.add(recipient: user0) 368 | messagesMediator.add(recipient: user1) 369 | 370 | spamMonster(message: "I'd Like to Add you to My Professional Network", worker: messagesMediator) 371 | 372 | /*: 373 | 💾 备忘录（Memento） 374 | -------------- 375 | 376 | 在不破坏封装性的前提下，捕获一个对象的内部状态，并在该对象之外保存这个状态。这样就可以将该对象恢复到原先保存的状态 377 | 378 | ### 示例： 379 | */ 380 | typealias Memento = [String: String] 381 | /*: 382 | 发起人（Originator） 383 | */ 384 | protocol MementoConvertible { 385 | var memento: Memento { get } 386 | init?(memento: Memento) 387 | } 388 | 389 | struct GameState: MementoConvertible { 390 | 391 | private enum Keys { 392 | static let chapter = "com.valve.halflife.chapter" 393 | static let weapon = "com.valve.halflife.weapon" 394 | } 395 | 396 | var chapter: String 397 | var weapon: String 398 | 399 | init(chapter: String, weapon: String) { 400 | self.chapter = chapter 401 | self.weapon = weapon 402 | } 403 | 404 | init?(memento: Memento) { 405 | guard let mementoChapter = memento[Keys.chapter], 406 | let mementoWeapon = memento[Keys.weapon] else { 407 | return nil 408 | } 409 | 410 | chapter = mementoChapter 411 | weapon = mementoWeapon 412 | } 413 | 414 | var memento: Memento { 415 | return [ Keys.chapter: chapter, Keys.weapon: weapon ] 416 | } 417 | } 418 | /*: 419 | 管理者（Caretaker） 420 | */ 421 | enum CheckPoint { 422 | 423 | private static let defaults = UserDefaults.standard 424 | 425 | static func save(_ state: MementoConvertible, saveName: String) { 426 | defaults.set(state.memento, forKey: saveName) 427 | defaults.synchronize() 428 | } 429 | 430 | static func restore(saveName: String) -> Any? { 431 | return defaults.object(forKey: saveName) 432 | } 433 | } 434 | /*: 435 | ### 用法 436 | */ 437 | var gameState = GameState(chapter: "Black Mesa Inbound", weapon: "Crowbar") 438 | 439 | gameState.chapter = "Anomalous Materials" 440 | gameState.weapon = "Glock 17" 441 | CheckPoint.save(gameState, saveName: "gameState1") 442 | 443 | gameState.chapter = "Unforeseen Consequences" 444 | gameState.weapon = "MP5" 445 | CheckPoint.save(gameState, saveName: "gameState2") 446 | 447 | gameState.chapter = "Office Complex" 448 | gameState.weapon = "Crossbow" 449 | CheckPoint.save(gameState, saveName: "gameState3") 450 | 451 | if let memento = CheckPoint.restore(saveName: "gameState1") as? Memento { 452 | let finalState = GameState(memento: memento) 453 | dump(finalState) 454 | } 455 | /*: 456 | 👓 观察者（Observer） 457 | --------------- 458 | 459 | 一个目标对象管理所有相依于它的观察者对象，并且在它本身的状态改变时主动发出通知 460 | 461 | ### 示例： 462 | */ 463 | protocol PropertyObserver : class { 464 | func willChange(propertyName: String, newPropertyValue: Any?) 465 | func didChange(propertyName: String, oldPropertyValue: Any?) 466 | } 467 | 468 | final class TestChambers { 469 | 470 | weak var observer:PropertyObserver? 471 | 472 | private let testChamberNumberName = "testChamberNumber" 473 | 474 | var testChamberNumber: Int = 0 { 475 | willSet(newValue) { 476 | observer?.willChange(propertyName: testChamberNumberName, newPropertyValue: newValue) 477 | } 478 | didSet { 479 | observer?.didChange(propertyName: testChamberNumberName, oldPropertyValue: oldValue) 480 | } 481 | } 482 | } 483 | 484 | final class Observer : PropertyObserver { 485 | func willChange(propertyName: String, newPropertyValue: Any?) { 486 | if newPropertyValue as? Int == 1 { 487 | print("Okay. Look. We both said a lot of things that you're going to regret.") 488 | } 489 | } 490 | 491 | func didChange(propertyName: String, oldPropertyValue: Any?) { 492 | if oldPropertyValue as? Int == 0 { 493 | print("Sorry about the mess. I've really let the place go since you killed me.") 494 | } 495 | } 496 | } 497 | /*: 498 | ### 用法 499 | */ 500 | var observerInstance = Observer() 501 | var testChambers = TestChambers() 502 | testChambers.observer = observerInstance 503 | testChambers.testChamberNumber += 1 504 | /*: 505 | 🐉 状态（State） 506 | --------- 507 | 508 | 在状态模式中，对象的行为是基于它的内部状态而改变的。 509 | 这个模式允许某个类对象在运行时发生改变。 510 | 511 | ### 示例： 512 | */ 513 | final class Context { 514 | private var state: State = UnauthorizedState() 515 | 516 | var isAuthorized: Bool { 517 | get { return state.isAuthorized(context: self) } 518 | } 519 | 520 | var userId: String? { 521 | get { return state.userId(context: self) } 522 | } 523 | 524 | func changeStateToAuthorized(userId: String) { 525 | state = AuthorizedState(userId: userId) 526 | } 527 | 528 | func changeStateToUnauthorized() { 529 | state = UnauthorizedState() 530 | } 531 | } 532 | 533 | protocol State { 534 | func isAuthorized(context: Context) -> Bool 535 | func userId(context: Context) -> String? 536 | } 537 | 538 | class UnauthorizedState: State { 539 | func isAuthorized(context: Context) -> Bool { return false } 540 | 541 | func userId(context: Context) -> String? { return nil } 542 | } 543 | 544 | class AuthorizedState: State { 545 | let userId: String 546 | 547 | init(userId: String) { self.userId = userId } 548 | 549 | func isAuthorized(context: Context) -> Bool { return true } 550 | 551 | func userId(context: Context) -> String? { return userId } 552 | } 553 | /*: 554 | ### 用法 555 | */ 556 | let userContext = Context() 557 | (userContext.isAuthorized, userContext.userId) 558 | userContext.changeStateToAuthorized(userId: "admin") 559 | (userContext.isAuthorized, userContext.userId) // now logged in as "admin" 560 | userContext.changeStateToUnauthorized() 561 | (userContext.isAuthorized, userContext.userId) 562 | /*: 563 | 💡 策略（Strategy） 564 | -------------- 565 | 566 | 对象有某个行为，但是在不同的场景中，该行为有不同的实现算法。策略模式： 567 | * 定义了一族算法（业务规则）； 568 | * 封装了每个算法； 569 | * 这族的算法可互换代替（interchangeable）。 570 | 571 | ### 示例： 572 | */ 573 | 574 | struct TestSubject { 575 | let pupilDiameter: Double 576 | let blushResponse: Double 577 | let isOrganic: Bool 578 | } 579 | 580 | protocol RealnessTesting: AnyObject { 581 | func testRealness(_ testSubject: TestSubject) -> Bool 582 | } 583 | 584 | final class VoightKampffTest: RealnessTesting { 585 | func testRealness(_ testSubject: TestSubject) -> Bool { 586 | return testSubject.pupilDiameter < 30.0 || testSubject.blushResponse == 0.0 587 | } 588 | } 589 | 590 | final class GeneticTest: RealnessTesting { 591 | func testRealness(_ testSubject: TestSubject) -> Bool { 592 | return testSubject.isOrganic 593 | } 594 | } 595 | 596 | final class BladeRunner { 597 | private let strategy: RealnessTesting 598 | 599 | init(test: RealnessTesting) { 600 | self.strategy = test 601 | } 602 | 603 | func testIfAndroid(_ testSubject: TestSubject) -> Bool { 604 | return !strategy.testRealness(testSubject) 605 | } 606 | } 607 | 608 | /*: 609 | ### 用法 610 | */ 611 | 612 | let rachel = TestSubject(pupilDiameter: 30.2, 613 | blushResponse: 0.3, 614 | isOrganic: false) 615 | 616 | // Deckard is using a traditional test 617 | let deckard = BladeRunner(test: VoightKampffTest()) 618 | let isRachelAndroid = deckard.testIfAndroid(rachel) 619 | 620 | // Gaff is using a very precise method 621 | let gaff = BladeRunner(test: GeneticTest()) 622 | let isDeckardAndroid = gaff.testIfAndroid(rachel) 623 | /*: 624 | 📝 模板方法模式 625 | ----------- 626 | 627 | 模板方法模式是一种行为设计模式， 它通过父类/协议中定义了一个算法的框架， 允许子类/具体实现对象在不修改结构的情况下重写算法的特定步骤。 628 | 629 | ### 示例： 630 | */ 631 | protocol Garden { 632 | func prepareSoil() 633 | func plantSeeds() 634 | func waterPlants() 635 | func prepareGarden() 636 | } 637 | 638 | extension Garden { 639 | 640 | func prepareGarden() { 641 | prepareSoil() 642 | plantSeeds() 643 | waterPlants() 644 | } 645 | } 646 | 647 | final class RoseGarden: Garden { 648 | 649 | func prepare() { 650 | prepareGarden() 651 | } 652 | 653 | func prepareSoil() { 654 | print ("prepare soil for rose garden") 655 | } 656 | 657 | func plantSeeds() { 658 | print ("plant seeds for rose garden") 659 | } 660 | 661 | func waterPlants() { 662 | print ("water the rose garden") 663 | } 664 | } 665 | 666 | /*: 667 | ### 用法 668 | */ 669 | 670 | let roseGarden = RoseGarden() 671 | roseGarden.prepare() 672 | /*: 673 | 🏃 访问者（Visitor） 674 | -------------- 675 | 676 | 封装某些作用于某种数据结构中各元素的操作，它可以在不改变数据结构的前提下定义作用于这些元素的新的操作。 677 | 678 | ### 示例： 679 | */ 680 | protocol PlanetVisitor { 681 | func visit(planet: PlanetAlderaan) 682 | func visit(planet: PlanetCoruscant) 683 | func visit(planet: PlanetTatooine) 684 | func visit(planet: MoonJedha) 685 | } 686 | 687 | protocol Planet { 688 | func accept(visitor: PlanetVisitor) 689 | } 690 | 691 | final class MoonJedha: Planet { 692 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 693 | } 694 | 695 | final class PlanetAlderaan: Planet { 696 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 697 | } 698 | 699 | final class PlanetCoruscant: Planet { 700 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 701 | } 702 | 703 | final class PlanetTatooine: Planet { 704 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 705 | } 706 | 707 | final class NameVisitor: PlanetVisitor { 708 | var name = "" 709 | 710 | func visit(planet: PlanetAlderaan) { name = "Alderaan" } 711 | func visit(planet: PlanetCoruscant) { name = "Coruscant" } 712 | func visit(planet: PlanetTatooine) { name = "Tatooine" } 713 | func visit(planet: MoonJedha) { name = "Jedha" } 714 | } 715 | 716 | /*: 717 | ### 用法 718 | */ 719 | let planets: [Planet] = [PlanetAlderaan(), PlanetCoruscant(), PlanetTatooine(), MoonJedha()] 720 | 721 | let names = planets.map { (planet: Planet) -> String in 722 | let visitor = NameVisitor() 723 | planet.accept(visitor: visitor) 724 | 725 | return visitor.name 726 | } 727 | 728 | names 729 | -------------------------------------------------------------------------------- /Design-Patterns-CN.playground/Pages/Creational.xcplaygroundpage/Contents.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 3 | 创建型模式 4 | ======== 5 | 6 | > 创建型模式是处理对象创建的设计模式，试图根据实际情况使用合适的方式创建对象。基本的对象创建方式可能会导致设计上的问题，或增加设计的复杂度。创建型模式通过以某种方式控制对象的创建来解决问题。 7 | > 8 | >**来源：** [维基百科](https://zh.wikipedia.org/wiki/%E5%89%B5%E5%BB%BA%E5%9E%8B%E6%A8%A1%E5%BC%8F) 9 | 10 | ## 目录 11 | 12 | * [行为型模式](Behavioral) 13 | * [创建型模式](Creational) 14 | * [结构型模式](Structural) 15 | */ 16 | import Foundation 17 | /*: 18 | 🌰 抽象工厂（Abstract Factory） 19 | ------------- 20 | 21 | 抽象工厂模式提供了一种方式，可以将一组具有同一主题的单独的工厂封装起来。在正常使用中，客户端程序需要创建抽象工厂的具体实现，然后使用抽象工厂作为接口来创建这一主题的具体对象。 22 | 23 | ### 示例： 24 | 25 | 协议 26 | */ 27 | 28 | protocol BurgerDescribing { 29 | var ingredients: [String] { get } 30 | } 31 | 32 | struct CheeseBurger: BurgerDescribing { 33 | let ingredients: [String] 34 | } 35 | 36 | protocol BurgerMaking { 37 | func make() -> BurgerDescribing 38 | } 39 | 40 | // 工厂方法实现 41 | 42 | final class BigKahunaBurger: BurgerMaking { 43 | func make() -> BurgerDescribing { 44 | return CheeseBurger(ingredients: ["Cheese", "Burger", "Lettuce", "Tomato"]) 45 | } 46 | } 47 | 48 | final class JackInTheBox: BurgerMaking { 49 | func make() -> BurgerDescribing { 50 | return CheeseBurger(ingredients: ["Cheese", "Burger", "Tomato", "Onions"]) 51 | } 52 | } 53 | 54 | /*: 55 | 抽象工厂 56 | */ 57 | 58 | enum BurgerFactoryType: BurgerMaking { 59 | 60 | case bigKahuna 61 | case jackInTheBox 62 | 63 | func make() -> BurgerDescribing { 64 | switch self { 65 | case .bigKahuna: 66 | return BigKahunaBurger().make() 67 | case .jackInTheBox: 68 | return JackInTheBox().make() 69 | } 70 | } 71 | } 72 | /*: 73 | ### 用法 74 | */ 75 | let bigKahuna = BurgerFactoryType.bigKahuna.make() 76 | let jackInTheBox = BurgerFactoryType.jackInTheBox.make() 77 | /*: 78 | 👷 生成器（Builder） 79 | -------------- 80 | 81 | 一种对象构建模式。它可以将复杂对象的建造过程抽象出来（抽象类别），使这个抽象过程的不同实现方法可以构造出不同表现（属性）的对象。 82 | 83 | ### 示例： 84 | */ 85 | final class DeathStarBuilder { 86 | 87 | var x: Double? 88 | var y: Double? 89 | var z: Double? 90 | 91 | typealias BuilderClosure = (DeathStarBuilder) -> () 92 | 93 | init(buildClosure: BuilderClosure) { 94 | buildClosure(self) 95 | } 96 | } 97 | 98 | struct DeathStar : CustomStringConvertible { 99 | 100 | let x: Double 101 | let y: Double 102 | let z: Double 103 | 104 | init?(builder: DeathStarBuilder) { 105 | 106 | if let x = builder.x, let y = builder.y, let z = builder.z { 107 | self.x = x 108 | self.y = y 109 | self.z = z 110 | } else { 111 | return nil 112 | } 113 | } 114 | 115 | var description:String { 116 | return "Death Star at (x:\(x) y:\(y) z:\(z))" 117 | } 118 | } 119 | /*: 120 | ### 用法 121 | */ 122 | let empire = DeathStarBuilder { builder in 123 | builder.x = 0.1 124 | builder.y = 0.2 125 | builder.z = 0.3 126 | } 127 | 128 | let deathStar = DeathStar(builder:empire) 129 | /*: 130 | 🏭 工厂方法（Factory Method） 131 | ----------------------- 132 | 133 | 定义一个创建对象的接口，但让实现这个接口的类来决定实例化哪个类。工厂方法让类的实例化推迟到子类中进行。 134 | 135 | ### 示例： 136 | */ 137 | protocol CurrencyDescribing { 138 | var symbol: String { get } 139 | var code: String { get } 140 | } 141 | 142 | final class Euro: CurrencyDescribing { 143 | var symbol: String { 144 | return "€" 145 | } 146 | 147 | var code: String { 148 | return "EUR" 149 | } 150 | } 151 | 152 | final class UnitedStatesDolar: CurrencyDescribing { 153 | var symbol: String { 154 | return "$" 155 | } 156 | 157 | var code: String { 158 | return "USD" 159 | } 160 | } 161 | 162 | enum Country { 163 | case unitedStates 164 | case spain 165 | case uk 166 | case greece 167 | } 168 | 169 | enum CurrencyFactory { 170 | static func currency(for country: Country) -> CurrencyDescribing? { 171 | 172 | switch country { 173 | case .spain, .greece: 174 | return Euro() 175 | case .unitedStates: 176 | return UnitedStatesDolar() 177 | default: 178 | return nil 179 | } 180 | 181 | } 182 | } 183 | /*: 184 | ### 用法 185 | */ 186 | let noCurrencyCode = "No Currency Code Available" 187 | 188 | CurrencyFactory.currency(for: .greece)?.code ?? noCurrencyCode 189 | CurrencyFactory.currency(for: .spain)?.code ?? noCurrencyCode 190 | CurrencyFactory.currency(for: .unitedStates)?.code ?? noCurrencyCode 191 | CurrencyFactory.currency(for: .uk)?.code ?? noCurrencyCode 192 | /*: 193 | 🔂 单态（Monostate） 194 | ------------ 195 | 196 | 单态模式是实现单一共享的另一种方法。不同于单例模式，它通过完全不同的机制，在不限制构造方法的情况下实现单一共享特性。 197 | 因此，在这种情况下，单态会将状态保存为静态，而不是将整个实例保存为单例。 198 | [单例和单态 - Robert C. Martin](http://staff.cs.utu.fi/~jounsmed/doos_06/material/SingletonAndMonostate.pdf) 199 | 200 | ### 示例: 201 | */ 202 | class Settings { 203 | 204 | enum Theme { 205 | case `default` 206 | case old 207 | case new 208 | } 209 | 210 | private static var theme: Theme? 211 | 212 | var currentTheme: Theme { 213 | get { Settings.theme ?? .default } 214 | set(newTheme) { Settings.theme = newTheme } 215 | } 216 | } 217 | /*: 218 | ### 用法: 219 | */ 220 | import SwiftUI 221 | 222 | // 改变主题 223 | let settings = Settings() // 开始使用主题 .old 224 | settings.currentTheme = .new // 改变主题为 .new 225 | 226 | // 界面一 227 | let screenColor: Color = Settings().currentTheme == .old ? .gray : .white 228 | 229 | // 界面二 230 | let screenTitle: String = Settings().currentTheme == .old ? "Itunes Connect" : "App Store Connect" 231 | /*: 232 | 🃏 原型（Prototype） 233 | -------------- 234 | 235 | 通过“复制”一个已经存在的实例来返回新的实例,而不是新建实例。被复制的实例就是我们所称的“原型”，这个原型是可定制的。 236 | 237 | ### 示例： 238 | */ 239 | class MoonWorker { 240 | 241 | let name: String 242 | var health: Int = 100 243 | 244 | init(name: String) { 245 | self.name = name 246 | } 247 | 248 | func clone() -> MoonWorker { 249 | return MoonWorker(name: name) 250 | } 251 | } 252 | /*: 253 | ### 用法 254 | */ 255 | let prototype = MoonWorker(name: "Sam Bell") 256 | 257 | var bell1 = prototype.clone() 258 | bell1.health = 12 259 | 260 | var bell2 = prototype.clone() 261 | bell2.health = 23 262 | 263 | var bell3 = prototype.clone() 264 | bell3.health = 0 265 | /*: 266 | 💍 单例（Singleton） 267 | -------------- 268 | 269 | 单例对象的类必须保证只有一个实例存在。许多时候整个系统只需要拥有一个的全局对象，这样有利于我们协调系统整体的行为 270 | 271 | ### 示例： 272 | */ 273 | final class ElonMusk { 274 | 275 | static let shared = ElonMusk() 276 | 277 | private init() { 278 | // Private initialization to ensure just one instance is created. 279 | } 280 | } 281 | /*: 282 | ### 用法 283 | */ 284 | let elon = ElonMusk.shared // There is only one Elon Musk folks. 285 | -------------------------------------------------------------------------------- /Design-Patterns-CN.playground/Pages/Index.xcplaygroundpage/Contents.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 3 | 设计模式（Swift 5.0 实现） 4 | ====================== 5 | 6 | ([Design-Patterns-CN.playground.zip](https://raw.githubusercontent.com/ochococo/Design-Patterns-In-Swift/master/Design-Patterns-CN.playground.zip)). 7 | 8 | 👷 源项目由 [@nsmeme](http://twitter.com/nsmeme) (Oktawian Chojnacki) 维护。 9 | 10 | 🇨🇳 中文版由 [@binglogo](https://twitter.com/binglogo) 整理翻译。 11 | 12 | ## 目录 13 | 14 | * [行为型模式](Behavioral) 15 | * [创建型模式](Creational) 16 | * [结构型模式](Structural) 17 | */ 18 | import Foundation 19 | 20 | print("您好！") 21 | -------------------------------------------------------------------------------- /Design-Patterns-CN.playground/Pages/Structural.xcplaygroundpage/Contents.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 3 | 结构型模式（Structural） 4 | ==================== 5 | 6 | > 在软件工程中结构型模式是设计模式，借由一以贯之的方式来了解元件间的关系，以简化设计。 7 | > 8 | >**来源：** [维基百科](https://zh.wikipedia.org/wiki/%E7%B5%90%E6%A7%8B%E5%9E%8B%E6%A8%A1%E5%BC%8F) 9 | 10 | ## 目录 11 | 12 | * [行为型模式](Behavioral) 13 | * [创建型模式](Creational) 14 | * [结构型模式](Structural) 15 | */ 16 | import Foundation 17 | /*: 18 | 🔌 适配器（Adapter） 19 | -------------- 20 | 21 | 适配器模式有时候也称包装样式或者包装(wrapper)。将一个类的接口转接成用户所期待的。一个适配使得因接口不兼容而不能在一起工作的类工作在一起，做法是将类自己的接口包裹在一个已存在的类中。 22 | 23 | ### 示例： 24 | */ 25 | protocol NewDeathStarSuperLaserAiming { 26 | var angleV: Double { get } 27 | var angleH: Double { get } 28 | } 29 | /*: 30 | **被适配者** 31 | */ 32 | struct OldDeathStarSuperlaserTarget { 33 | let angleHorizontal: Float 34 | let angleVertical: Float 35 | 36 | init(angleHorizontal: Float, angleVertical: Float) { 37 | self.angleHorizontal = angleHorizontal 38 | self.angleVertical = angleVertical 39 | } 40 | } 41 | /*: 42 | **适配器** 43 | */ 44 | struct NewDeathStarSuperlaserTarget: NewDeathStarSuperLaserAiming { 45 | 46 | private let target: OldDeathStarSuperlaserTarget 47 | 48 | var angleV: Double { 49 | return Double(target.angleVertical) 50 | } 51 | 52 | var angleH: Double { 53 | return Double(target.angleHorizontal) 54 | } 55 | 56 | init(_ target: OldDeathStarSuperlaserTarget) { 57 | self.target = target 58 | } 59 | } 60 | /*: 61 | ### 用法 62 | */ 63 | let target = OldDeathStarSuperlaserTarget(angleHorizontal: 14.0, angleVertical: 12.0) 64 | let newFormat = NewDeathStarSuperlaserTarget(target) 65 | 66 | newFormat.angleH 67 | newFormat.angleV 68 | /*: 69 | 🌉 桥接（Bridge） 70 | ----------- 71 | 72 | 桥接模式将抽象部分与实现部分分离，使它们都可以独立的变化。 73 | 74 | ### 示例： 75 | */ 76 | protocol Switch { 77 | var appliance: Appliance { get set } 78 | func turnOn() 79 | } 80 | 81 | protocol Appliance { 82 | func run() 83 | } 84 | 85 | final class RemoteControl: Switch { 86 | var appliance: Appliance 87 | 88 | func turnOn() { 89 | self.appliance.run() 90 | } 91 | 92 | init(appliance: Appliance) { 93 | self.appliance = appliance 94 | } 95 | } 96 | 97 | final class TV: Appliance { 98 | func run() { 99 | print("tv turned on"); 100 | } 101 | } 102 | 103 | final class VacuumCleaner: Appliance { 104 | func run() { 105 | print("vacuum cleaner turned on") 106 | } 107 | } 108 | /*: 109 | ### 用法 110 | */ 111 | let tvRemoteControl = RemoteControl(appliance: TV()) 112 | tvRemoteControl.turnOn() 113 | 114 | let fancyVacuumCleanerRemoteControl = RemoteControl(appliance: VacuumCleaner()) 115 | fancyVacuumCleanerRemoteControl.turnOn() 116 | /*: 117 | 🌿 组合（Composite） 118 | -------------- 119 | 120 | 将对象组合成树形结构以表示‘部分-整体’的层次结构。组合模式使得用户对单个对象和组合对象的使用具有一致性。 121 | 122 | ### 示例： 123 | 124 | 组件（Component） 125 | */ 126 | protocol Shape { 127 | func draw(fillColor: String) 128 | } 129 | /*: 130 | 叶子节点（Leafs） 131 | */ 132 | final class Square: Shape { 133 | func draw(fillColor: String) { 134 | print("Drawing a Square with color \(fillColor)") 135 | } 136 | } 137 | 138 | final class Circle: Shape { 139 | func draw(fillColor: String) { 140 | print("Drawing a circle with color \(fillColor)") 141 | } 142 | } 143 | 144 | /*: 145 | 组合 146 | */ 147 | final class Whiteboard: Shape { 148 | 149 | private lazy var shapes = [Shape]() 150 | 151 | init(_ shapes: Shape...) { 152 | self.shapes = shapes 153 | } 154 | 155 | func draw(fillColor: String) { 156 | for shape in self.shapes { 157 | shape.draw(fillColor: fillColor) 158 | } 159 | } 160 | } 161 | /*: 162 | ### 用法 163 | */ 164 | var whiteboard = Whiteboard(Circle(), Square()) 165 | whiteboard.draw(fillColor: "Red") 166 | /*: 167 | 🍧 修饰（Decorator） 168 | -------------- 169 | 170 | 修饰模式，是面向对象编程领域中，一种动态地往一个类中添加新的行为的设计模式。 171 | 就功能而言，修饰模式相比生成子类更为灵活，这样可以给某个对象而不是整个类添加一些功能。 172 | 173 | ### 示例： 174 | */ 175 | protocol CostHaving { 176 | var cost: Double { get } 177 | } 178 | 179 | protocol IngredientsHaving { 180 | var ingredients: [String] { get } 181 | } 182 | 183 | typealias BeverageDataHaving = CostHaving & IngredientsHaving 184 | 185 | struct SimpleCoffee: BeverageDataHaving { 186 | let cost: Double = 1.0 187 | let ingredients = ["Water", "Coffee"] 188 | } 189 | 190 | protocol BeverageHaving: BeverageDataHaving { 191 | var beverage: BeverageDataHaving { get } 192 | } 193 | 194 | struct Milk: BeverageHaving { 195 | 196 | let beverage: BeverageDataHaving 197 | 198 | var cost: Double { 199 | return beverage.cost + 0.5 200 | } 201 | 202 | var ingredients: [String] { 203 | return beverage.ingredients + ["Milk"] 204 | } 205 | } 206 | 207 | struct WhipCoffee: BeverageHaving { 208 | 209 | let beverage: BeverageDataHaving 210 | 211 | var cost: Double { 212 | return beverage.cost + 0.5 213 | } 214 | 215 | var ingredients: [String] { 216 | return beverage.ingredients + ["Whip"] 217 | } 218 | } 219 | /*: 220 | ### 用法 221 | */ 222 | var someCoffee: BeverageDataHaving = SimpleCoffee() 223 | print("Cost: \(someCoffee.cost); Ingredients: \(someCoffee.ingredients)") 224 | someCoffee = Milk(beverage: someCoffee) 225 | print("Cost: \(someCoffee.cost); Ingredients: \(someCoffee.ingredients)") 226 | someCoffee = WhipCoffee(beverage: someCoffee) 227 | print("Cost: \(someCoffee.cost); Ingredients: \(someCoffee.ingredients)") 228 | /*: 229 | 🎁 外观（Facade） 230 | ----------- 231 | 232 | 外观模式为子系统中的一组接口提供一个统一的高层接口，使得子系统更容易使用。 233 | 234 | ### 示例： 235 | */ 236 | final class Defaults { 237 | 238 | private let defaults: UserDefaults 239 | 240 | init(defaults: UserDefaults = .standard) { 241 | self.defaults = defaults 242 | } 243 | 244 | subscript(key: String) -> String? { 245 | get { 246 | return defaults.string(forKey: key) 247 | } 248 | 249 | set { 250 | defaults.set(newValue, forKey: key) 251 | } 252 | } 253 | } 254 | /*: 255 | ### 用法 256 | */ 257 | let storage = Defaults() 258 | 259 | // Store 260 | storage["Bishop"] = "Disconnect me. I’d rather be nothing" 261 | 262 | // Read 263 | storage["Bishop"] 264 | /*: 265 | 🍃 享元（Flyweight） 266 | -------------- 267 | 268 | 使用共享物件，用来尽可能减少内存使用量以及分享资讯给尽可能多的相似物件；它适合用于当大量物件只是重复因而导致无法令人接受的使用大量内存。 269 | 270 | ### 示例： 271 | */ 272 | // 特指咖啡生成的对象会是享元 273 | struct SpecialityCoffee { 274 | let origin: String 275 | } 276 | 277 | protocol CoffeeSearching { 278 | func search(origin: String) -> SpecialityCoffee? 279 | } 280 | 281 | // 菜单充当特制咖啡享元对象的工厂和缓存 282 | final class Menu: CoffeeSearching { 283 | 284 | private var coffeeAvailable: [String: SpecialityCoffee] = [:] 285 | 286 | func search(origin: String) -> SpecialityCoffee? { 287 | if coffeeAvailable.index(forKey: origin) == nil { 288 | coffeeAvailable[origin] = SpecialityCoffee(origin: origin) 289 | } 290 | 291 | return coffeeAvailable[origin] 292 | } 293 | } 294 | 295 | final class CoffeeShop { 296 | private var orders: [Int: SpecialityCoffee] = [:] 297 | private let menu: CoffeeSearching 298 | 299 | init(menu: CoffeeSearching) { 300 | self.menu = menu 301 | } 302 | 303 | func takeOrder(origin: String, table: Int) { 304 | orders[table] = menu.search(origin: origin) 305 | } 306 | 307 | func serve() { 308 | for (table, origin) in orders { 309 | print("Serving \(origin) to table \(table)") 310 | } 311 | } 312 | } 313 | /*: 314 | ### 用法 315 | */ 316 | let coffeeShop = CoffeeShop(menu: Menu()) 317 | 318 | coffeeShop.takeOrder(origin: "Yirgacheffe, Ethiopia", table: 1) 319 | coffeeShop.takeOrder(origin: "Buziraguhindwa, Burundi", table: 3) 320 | 321 | coffeeShop.serve() 322 | /*: 323 | ☔ 保护代理模式（Protection Proxy） 324 | ------------------ 325 | 326 | 在代理模式中，创建一个类代表另一个底层类的功能。 327 | 保护代理用于限制访问。 328 | 329 | ### 示例： 330 | */ 331 | protocol DoorOpening { 332 | func open(doors: String) -> String 333 | } 334 | 335 | final class HAL9000: DoorOpening { 336 | func open(doors: String) -> String { 337 | return ("HAL9000: Affirmative, Dave. I read you. Opened \(doors).") 338 | } 339 | } 340 | 341 | final class CurrentComputer: DoorOpening { 342 | private var computer: HAL9000! 343 | 344 | func authenticate(password: String) -> Bool { 345 | 346 | guard password == "pass" else { 347 | return false 348 | } 349 | 350 | computer = HAL9000() 351 | 352 | return true 353 | } 354 | 355 | func open(doors: String) -> String { 356 | 357 | guard computer != nil else { 358 | return "Access Denied. I'm afraid I can't do that." 359 | } 360 | 361 | return computer.open(doors: doors) 362 | } 363 | } 364 | /*: 365 | ### 用法 366 | */ 367 | let computer = CurrentComputer() 368 | let podBay = "Pod Bay Doors" 369 | 370 | computer.open(doors: podBay) 371 | 372 | computer.authenticate(password: "pass") 373 | computer.open(doors: podBay) 374 | /*: 375 | 🍬 虚拟代理（Virtual Proxy） 376 | ---------------- 377 | 378 | 在代理模式中，创建一个类代表另一个底层类的功能。 379 | 虚拟代理用于对象的需时加载。 380 | 381 | ### 示例： 382 | */ 383 | protocol HEVSuitMedicalAid { 384 | func administerMorphine() -> String 385 | } 386 | 387 | final class HEVSuit: HEVSuitMedicalAid { 388 | func administerMorphine() -> String { 389 | return "Morphine administered." 390 | } 391 | } 392 | 393 | final class HEVSuitHumanInterface: HEVSuitMedicalAid { 394 | 395 | lazy private var physicalSuit: HEVSuit = HEVSuit() 396 | 397 | func administerMorphine() -> String { 398 | return physicalSuit.administerMorphine() 399 | } 400 | } 401 | /*: 402 | ### 用法 403 | */ 404 | let humanInterface = HEVSuitHumanInterface() 405 | humanInterface.administerMorphine() 406 | -------------------------------------------------------------------------------- /Design-Patterns-CN.playground/Pages/Structural.xcplaygroundpage/timeline.xctimeline: -------------------------------------------------------------------------------- 1 | 2 | 4 | 5 | 6 | 7 | -------------------------------------------------------------------------------- /Design-Patterns-CN.playground/contents.xcplayground: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | -------------------------------------------------------------------------------- /Design-Patterns.playground.zip: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/evnaz/Design-Patterns-In-Swift/bd6dfaf9a241d418b3ec70a9faa275ffe279865e/Design-Patterns.playground.zip -------------------------------------------------------------------------------- /Design-Patterns.playground/Pages/Behavioral.xcplaygroundpage/Contents.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 3 | Behavioral 4 | ========== 5 | 6 | >In software engineering, behavioral design patterns are design patterns that identify common communication patterns between objects and realize these patterns. By doing so, these patterns increase flexibility in carrying out this communication. 7 | > 8 | >**Source:** [wikipedia.org](http://en.wikipedia.org/wiki/Behavioral_pattern) 9 | 10 | ## Table of Contents 11 | 12 | * [Behavioral](Behavioral) 13 | * [Creational](Creational) 14 | * [Structural](Structural) 15 | 16 | */ 17 | import Foundation 18 | /*: 19 | 🐝 Chain Of Responsibility 20 | -------------------------- 21 | 22 | The chain of responsibility pattern is used to process varied requests, each of which may be dealt with by a different handler. 23 | 24 | ### Example: 25 | */ 26 | 27 | protocol Withdrawing { 28 | func withdraw(amount: Int) -> Bool 29 | } 30 | 31 | final class MoneyPile: Withdrawing { 32 | 33 | let value: Int 34 | var quantity: Int 35 | var next: Withdrawing? 36 | 37 | init(value: Int, quantity: Int, next: Withdrawing?) { 38 | self.value = value 39 | self.quantity = quantity 40 | self.next = next 41 | } 42 | 43 | func withdraw(amount: Int) -> Bool { 44 | 45 | var amount = amount 46 | 47 | func canTakeSomeBill(want: Int) -> Bool { 48 | return (want / self.value) > 0 49 | } 50 | 51 | var quantity = self.quantity 52 | 53 | while canTakeSomeBill(want: amount) { 54 | 55 | if quantity == 0 { 56 | break 57 | } 58 | 59 | amount -= self.value 60 | quantity -= 1 61 | } 62 | 63 | guard amount > 0 else { 64 | return true 65 | } 66 | 67 | if let next = self.next { 68 | return next.withdraw(amount: amount) 69 | } 70 | 71 | return false 72 | } 73 | } 74 | 75 | final class ATM: Withdrawing { 76 | 77 | private var hundred: Withdrawing 78 | private var fifty: Withdrawing 79 | private var twenty: Withdrawing 80 | private var ten: Withdrawing 81 | 82 | private var startPile: Withdrawing { 83 | return self.hundred 84 | } 85 | 86 | init(hundred: Withdrawing, 87 | fifty: Withdrawing, 88 | twenty: Withdrawing, 89 | ten: Withdrawing) { 90 | 91 | self.hundred = hundred 92 | self.fifty = fifty 93 | self.twenty = twenty 94 | self.ten = ten 95 | } 96 | 97 | func withdraw(amount: Int) -> Bool { 98 | return startPile.withdraw(amount: amount) 99 | } 100 | } 101 | /*: 102 | ### Usage 103 | */ 104 | // Create piles of money and link them together 10 < 20 < 50 < 100.** 105 | let ten = MoneyPile(value: 10, quantity: 6, next: nil) 106 | let twenty = MoneyPile(value: 20, quantity: 2, next: ten) 107 | let fifty = MoneyPile(value: 50, quantity: 2, next: twenty) 108 | let hundred = MoneyPile(value: 100, quantity: 1, next: fifty) 109 | 110 | // Build ATM. 111 | var atm = ATM(hundred: hundred, fifty: fifty, twenty: twenty, ten: ten) 112 | atm.withdraw(amount: 310) // Cannot because ATM has only 300 113 | atm.withdraw(amount: 100) // Can withdraw - 1x100 114 | /*: 115 | 👫 Command 116 | ---------- 117 | 118 | The command pattern is used to express a request, including the call to be made and all of its required parameters, in a command object. The command may then be executed immediately or held for later use. 119 | 120 | ### Example: 121 | */ 122 | protocol DoorCommand { 123 | func execute() -> String 124 | } 125 | 126 | final class OpenCommand: DoorCommand { 127 | let doors:String 128 | 129 | required init(doors: String) { 130 | self.doors = doors 131 | } 132 | 133 | func execute() -> String { 134 | return "Opened \(doors)" 135 | } 136 | } 137 | 138 | final class CloseCommand: DoorCommand { 139 | let doors:String 140 | 141 | required init(doors: String) { 142 | self.doors = doors 143 | } 144 | 145 | func execute() -> String { 146 | return "Closed \(doors)" 147 | } 148 | } 149 | 150 | final class HAL9000DoorsOperations { 151 | let openCommand: DoorCommand 152 | let closeCommand: DoorCommand 153 | 154 | init(doors: String) { 155 | self.openCommand = OpenCommand(doors:doors) 156 | self.closeCommand = CloseCommand(doors:doors) 157 | } 158 | 159 | func close() -> String { 160 | return closeCommand.execute() 161 | } 162 | 163 | func open() -> String { 164 | return openCommand.execute() 165 | } 166 | } 167 | /*: 168 | ### Usage: 169 | */ 170 | let podBayDoors = "Pod Bay Doors" 171 | let doorModule = HAL9000DoorsOperations(doors:podBayDoors) 172 | 173 | doorModule.open() 174 | doorModule.close() 175 | /*: 176 | 🎶 Interpreter 177 | -------------- 178 | 179 | The interpreter pattern is used to evaluate sentences in a language. 180 | 181 | ### Example 182 | */ 183 | 184 | protocol IntegerExpression { 185 | func evaluate(_ context: IntegerContext) -> Int 186 | func replace(character: Character, integerExpression: IntegerExpression) -> IntegerExpression 187 | func copied() -> IntegerExpression 188 | } 189 | 190 | final class IntegerContext { 191 | private var data: [Character:Int] = [:] 192 | 193 | func lookup(name: Character) -> Int { 194 | return self.data[name]! 195 | } 196 | 197 | func assign(expression: IntegerVariableExpression, value: Int) { 198 | self.data[expression.name] = value 199 | } 200 | } 201 | 202 | final class IntegerVariableExpression: IntegerExpression { 203 | let name: Character 204 | 205 | init(name: Character) { 206 | self.name = name 207 | } 208 | 209 | func evaluate(_ context: IntegerContext) -> Int { 210 | return context.lookup(name: self.name) 211 | } 212 | 213 | func replace(character name: Character, integerExpression: IntegerExpression) -> IntegerExpression { 214 | if name == self.name { 215 | return integerExpression.copied() 216 | } else { 217 | return IntegerVariableExpression(name: self.name) 218 | } 219 | } 220 | 221 | func copied() -> IntegerExpression { 222 | return IntegerVariableExpression(name: self.name) 223 | } 224 | } 225 | 226 | final class AddExpression: IntegerExpression { 227 | private var operand1: IntegerExpression 228 | private var operand2: IntegerExpression 229 | 230 | init(op1: IntegerExpression, op2: IntegerExpression) { 231 | self.operand1 = op1 232 | self.operand2 = op2 233 | } 234 | 235 | func evaluate(_ context: IntegerContext) -> Int { 236 | return self.operand1.evaluate(context) + self.operand2.evaluate(context) 237 | } 238 | 239 | func replace(character: Character, integerExpression: IntegerExpression) -> IntegerExpression { 240 | return AddExpression(op1: operand1.replace(character: character, integerExpression: integerExpression), 241 | op2: operand2.replace(character: character, integerExpression: integerExpression)) 242 | } 243 | 244 | func copied() -> IntegerExpression { 245 | return AddExpression(op1: self.operand1, op2: self.operand2) 246 | } 247 | } 248 | /*: 249 | ### Usage 250 | */ 251 | var context = IntegerContext() 252 | 253 | var a = IntegerVariableExpression(name: "A") 254 | var b = IntegerVariableExpression(name: "B") 255 | var c = IntegerVariableExpression(name: "C") 256 | 257 | var expression = AddExpression(op1: a, op2: AddExpression(op1: b, op2: c)) // a + (b + c) 258 | 259 | context.assign(expression: a, value: 2) 260 | context.assign(expression: b, value: 1) 261 | context.assign(expression: c, value: 3) 262 | 263 | var result = expression.evaluate(context) 264 | /*: 265 | 🍫 Iterator 266 | ----------- 267 | 268 | The iterator pattern is used to provide a standard interface for traversing a collection of items in an aggregate object without the need to understand its underlying structure. 269 | 270 | ### Example: 271 | */ 272 | struct Novella { 273 | let name: String 274 | } 275 | 276 | struct Novellas { 277 | let novellas: [Novella] 278 | } 279 | 280 | struct NovellasIterator: IteratorProtocol { 281 | 282 | private var current = 0 283 | private let novellas: [Novella] 284 | 285 | init(novellas: [Novella]) { 286 | self.novellas = novellas 287 | } 288 | 289 | mutating func next() -> Novella? { 290 | defer { current += 1 } 291 | return novellas.count > current ? novellas[current] : nil 292 | } 293 | } 294 | 295 | extension Novellas: Sequence { 296 | func makeIterator() -> NovellasIterator { 297 | return NovellasIterator(novellas: novellas) 298 | } 299 | } 300 | /*: 301 | ### Usage 302 | */ 303 | let greatNovellas = Novellas(novellas: [Novella(name: "The Mist")] ) 304 | 305 | for novella in greatNovellas { 306 | print("I've read: \(novella)") 307 | } 308 | /*: 309 | 💐 Mediator 310 | ----------- 311 | 312 | The mediator pattern is used to reduce coupling between classes that communicate with each other. Instead of classes communicating directly, and thus requiring knowledge of their implementation, the classes send messages via a mediator object. 313 | 314 | ### Example 315 | */ 316 | protocol Receiver { 317 | associatedtype MessageType 318 | func receive(message: MessageType) 319 | } 320 | 321 | protocol Sender { 322 | associatedtype MessageType 323 | associatedtype ReceiverType: Receiver 324 | 325 | var recipients: [ReceiverType] { get } 326 | 327 | func send(message: MessageType) 328 | } 329 | 330 | struct Programmer: Receiver { 331 | let name: String 332 | 333 | init(name: String) { 334 | self.name = name 335 | } 336 | 337 | func receive(message: String) { 338 | print("\(name) received: \(message)") 339 | } 340 | } 341 | 342 | final class MessageMediator: Sender { 343 | internal var recipients: [Programmer] = [] 344 | 345 | func add(recipient: Programmer) { 346 | recipients.append(recipient) 347 | } 348 | 349 | func send(message: String) { 350 | for recipient in recipients { 351 | recipient.receive(message: message) 352 | } 353 | } 354 | } 355 | 356 | /*: 357 | ### Usage 358 | */ 359 | func spamMonster(message: String, worker: MessageMediator) { 360 | worker.send(message: message) 361 | } 362 | 363 | let messagesMediator = MessageMediator() 364 | 365 | let user0 = Programmer(name: "Linus Torvalds") 366 | let user1 = Programmer(name: "Avadis 'Avie' Tevanian") 367 | messagesMediator.add(recipient: user0) 368 | messagesMediator.add(recipient: user1) 369 | 370 | spamMonster(message: "I'd Like to Add you to My Professional Network", worker: messagesMediator) 371 | 372 | /*: 373 | 💾 Memento 374 | ---------- 375 | 376 | The memento pattern is used to capture the current state of an object and store it in such a manner that it can be restored at a later time without breaking the rules of encapsulation. 377 | 378 | ### Example 379 | */ 380 | typealias Memento = [String: String] 381 | /*: 382 | Originator 383 | */ 384 | protocol MementoConvertible { 385 | var memento: Memento { get } 386 | init?(memento: Memento) 387 | } 388 | 389 | struct GameState: MementoConvertible { 390 | 391 | private enum Keys { 392 | static let chapter = "com.valve.halflife.chapter" 393 | static let weapon = "com.valve.halflife.weapon" 394 | } 395 | 396 | var chapter: String 397 | var weapon: String 398 | 399 | init(chapter: String, weapon: String) { 400 | self.chapter = chapter 401 | self.weapon = weapon 402 | } 403 | 404 | init?(memento: Memento) { 405 | guard let mementoChapter = memento[Keys.chapter], 406 | let mementoWeapon = memento[Keys.weapon] else { 407 | return nil 408 | } 409 | 410 | chapter = mementoChapter 411 | weapon = mementoWeapon 412 | } 413 | 414 | var memento: Memento { 415 | return [ Keys.chapter: chapter, Keys.weapon: weapon ] 416 | } 417 | } 418 | /*: 419 | Caretaker 420 | */ 421 | enum CheckPoint { 422 | 423 | private static let defaults = UserDefaults.standard 424 | 425 | static func save(_ state: MementoConvertible, saveName: String) { 426 | defaults.set(state.memento, forKey: saveName) 427 | defaults.synchronize() 428 | } 429 | 430 | static func restore(saveName: String) -> Any? { 431 | return defaults.object(forKey: saveName) 432 | } 433 | } 434 | /*: 435 | ### Usage 436 | */ 437 | var gameState = GameState(chapter: "Black Mesa Inbound", weapon: "Crowbar") 438 | 439 | gameState.chapter = "Anomalous Materials" 440 | gameState.weapon = "Glock 17" 441 | CheckPoint.save(gameState, saveName: "gameState1") 442 | 443 | gameState.chapter = "Unforeseen Consequences" 444 | gameState.weapon = "MP5" 445 | CheckPoint.save(gameState, saveName: "gameState2") 446 | 447 | gameState.chapter = "Office Complex" 448 | gameState.weapon = "Crossbow" 449 | CheckPoint.save(gameState, saveName: "gameState3") 450 | 451 | if let memento = CheckPoint.restore(saveName: "gameState1") as? Memento { 452 | let finalState = GameState(memento: memento) 453 | dump(finalState) 454 | } 455 | /*: 456 | 👓 Observer 457 | ----------- 458 | 459 | The observer pattern is used to allow an object to publish changes to its state. 460 | Other objects subscribe to be immediately notified of any changes. 461 | 462 | ### Example 463 | */ 464 | protocol PropertyObserver : class { 465 | func willChange(propertyName: String, newPropertyValue: Any?) 466 | func didChange(propertyName: String, oldPropertyValue: Any?) 467 | } 468 | 469 | final class TestChambers { 470 | 471 | weak var observer:PropertyObserver? 472 | 473 | private let testChamberNumberName = "testChamberNumber" 474 | 475 | var testChamberNumber: Int = 0 { 476 | willSet(newValue) { 477 | observer?.willChange(propertyName: testChamberNumberName, newPropertyValue: newValue) 478 | } 479 | didSet { 480 | observer?.didChange(propertyName: testChamberNumberName, oldPropertyValue: oldValue) 481 | } 482 | } 483 | } 484 | 485 | final class Observer : PropertyObserver { 486 | func willChange(propertyName: String, newPropertyValue: Any?) { 487 | if newPropertyValue as? Int == 1 { 488 | print("Okay. Look. We both said a lot of things that you're going to regret.") 489 | } 490 | } 491 | 492 | func didChange(propertyName: String, oldPropertyValue: Any?) { 493 | if oldPropertyValue as? Int == 0 { 494 | print("Sorry about the mess. I've really let the place go since you killed me.") 495 | } 496 | } 497 | } 498 | /*: 499 | ### Usage 500 | */ 501 | var observerInstance = Observer() 502 | var testChambers = TestChambers() 503 | testChambers.observer = observerInstance 504 | testChambers.testChamberNumber += 1 505 | /*: 506 | 🐉 State 507 | --------- 508 | 509 | The state pattern is used to alter the behaviour of an object as its internal state changes. 510 | The pattern allows the class for an object to apparently change at run-time. 511 | 512 | ### Example 513 | */ 514 | final class Context { 515 | private var state: State = UnauthorizedState() 516 | 517 | var isAuthorized: Bool { 518 | get { return state.isAuthorized(context: self) } 519 | } 520 | 521 | var userId: String? { 522 | get { return state.userId(context: self) } 523 | } 524 | 525 | func changeStateToAuthorized(userId: String) { 526 | state = AuthorizedState(userId: userId) 527 | } 528 | 529 | func changeStateToUnauthorized() { 530 | state = UnauthorizedState() 531 | } 532 | } 533 | 534 | protocol State { 535 | func isAuthorized(context: Context) -> Bool 536 | func userId(context: Context) -> String? 537 | } 538 | 539 | class UnauthorizedState: State { 540 | func isAuthorized(context: Context) -> Bool { return false } 541 | 542 | func userId(context: Context) -> String? { return nil } 543 | } 544 | 545 | class AuthorizedState: State { 546 | let userId: String 547 | 548 | init(userId: String) { self.userId = userId } 549 | 550 | func isAuthorized(context: Context) -> Bool { return true } 551 | 552 | func userId(context: Context) -> String? { return userId } 553 | } 554 | /*: 555 | ### Usage 556 | */ 557 | let userContext = Context() 558 | (userContext.isAuthorized, userContext.userId) 559 | userContext.changeStateToAuthorized(userId: "admin") 560 | (userContext.isAuthorized, userContext.userId) // now logged in as "admin" 561 | userContext.changeStateToUnauthorized() 562 | (userContext.isAuthorized, userContext.userId) 563 | /*: 564 | 💡 Strategy 565 | ----------- 566 | 567 | The strategy pattern is used to create an interchangeable family of algorithms from which the required process is chosen at run-time. 568 | 569 | ### Example 570 | */ 571 | 572 | struct TestSubject { 573 | let pupilDiameter: Double 574 | let blushResponse: Double 575 | let isOrganic: Bool 576 | } 577 | 578 | protocol RealnessTesting: AnyObject { 579 | func testRealness(_ testSubject: TestSubject) -> Bool 580 | } 581 | 582 | final class VoightKampffTest: RealnessTesting { 583 | func testRealness(_ testSubject: TestSubject) -> Bool { 584 | return testSubject.pupilDiameter < 30.0 || testSubject.blushResponse == 0.0 585 | } 586 | } 587 | 588 | final class GeneticTest: RealnessTesting { 589 | func testRealness(_ testSubject: TestSubject) -> Bool { 590 | return testSubject.isOrganic 591 | } 592 | } 593 | 594 | final class BladeRunner { 595 | private let strategy: RealnessTesting 596 | 597 | init(test: RealnessTesting) { 598 | self.strategy = test 599 | } 600 | 601 | func testIfAndroid(_ testSubject: TestSubject) -> Bool { 602 | return !strategy.testRealness(testSubject) 603 | } 604 | } 605 | 606 | /*: 607 | ### Usage 608 | */ 609 | 610 | let rachel = TestSubject(pupilDiameter: 30.2, 611 | blushResponse: 0.3, 612 | isOrganic: false) 613 | 614 | // Deckard is using a traditional test 615 | let deckard = BladeRunner(test: VoightKampffTest()) 616 | let isRachelAndroid = deckard.testIfAndroid(rachel) 617 | 618 | // Gaff is using a very precise method 619 | let gaff = BladeRunner(test: GeneticTest()) 620 | let isDeckardAndroid = gaff.testIfAndroid(rachel) 621 | /*: 622 | 📝 Template Method 623 | ----------- 624 | 625 | The template method pattern defines the steps of an algorithm and allows the redefinition of one or more of these steps. In this way, the template method protects the algorithm, the order of execution and provides abstract methods that can be implemented by concrete types. 626 | 627 | ### Example 628 | */ 629 | protocol Garden { 630 | func prepareSoil() 631 | func plantSeeds() 632 | func waterPlants() 633 | func prepareGarden() 634 | } 635 | 636 | extension Garden { 637 | 638 | func prepareGarden() { 639 | prepareSoil() 640 | plantSeeds() 641 | waterPlants() 642 | } 643 | } 644 | 645 | final class RoseGarden: Garden { 646 | 647 | func prepare() { 648 | prepareGarden() 649 | } 650 | 651 | func prepareSoil() { 652 | print ("prepare soil for rose garden") 653 | } 654 | 655 | func plantSeeds() { 656 | print ("plant seeds for rose garden") 657 | } 658 | 659 | func waterPlants() { 660 | print ("water the rose garden") 661 | } 662 | } 663 | 664 | /*: 665 | ### Usage 666 | */ 667 | 668 | let roseGarden = RoseGarden() 669 | roseGarden.prepare() 670 | /*: 671 | 🏃 Visitor 672 | ---------- 673 | 674 | The visitor pattern is used to separate a relatively complex set of structured data classes from the functionality that may be performed upon the data that they hold. 675 | 676 | ### Example 677 | */ 678 | protocol PlanetVisitor { 679 | func visit(planet: PlanetAlderaan) 680 | func visit(planet: PlanetCoruscant) 681 | func visit(planet: PlanetTatooine) 682 | func visit(planet: MoonJedha) 683 | } 684 | 685 | protocol Planet { 686 | func accept(visitor: PlanetVisitor) 687 | } 688 | 689 | final class MoonJedha: Planet { 690 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 691 | } 692 | 693 | final class PlanetAlderaan: Planet { 694 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 695 | } 696 | 697 | final class PlanetCoruscant: Planet { 698 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 699 | } 700 | 701 | final class PlanetTatooine: Planet { 702 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 703 | } 704 | 705 | final class NameVisitor: PlanetVisitor { 706 | var name = "" 707 | 708 | func visit(planet: PlanetAlderaan) { name = "Alderaan" } 709 | func visit(planet: PlanetCoruscant) { name = "Coruscant" } 710 | func visit(planet: PlanetTatooine) { name = "Tatooine" } 711 | func visit(planet: MoonJedha) { name = "Jedha" } 712 | } 713 | 714 | /*: 715 | ### Usage 716 | */ 717 | let planets: [Planet] = [PlanetAlderaan(), PlanetCoruscant(), PlanetTatooine(), MoonJedha()] 718 | 719 | let names = planets.map { (planet: Planet) -> String in 720 | let visitor = NameVisitor() 721 | planet.accept(visitor: visitor) 722 | 723 | return visitor.name 724 | } 725 | 726 | names 727 | -------------------------------------------------------------------------------- /Design-Patterns.playground/Pages/Creational.xcplaygroundpage/Contents.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 3 | Creational 4 | ========== 5 | 6 | > In software engineering, creational design patterns are design patterns that deal with object creation mechanisms, trying to create objects in a manner suitable to the situation. The basic form of object creation could result in design problems or added complexity to the design. Creational design patterns solve this problem by somehow controlling this object creation. 7 | > 8 | >**Source:** [wikipedia.org](http://en.wikipedia.org/wiki/Creational_pattern) 9 | 10 | ## Table of Contents 11 | 12 | * [Behavioral](Behavioral) 13 | * [Creational](Creational) 14 | * [Structural](Structural) 15 | 16 | */ 17 | import Foundation 18 | /*: 19 | 🌰 Abstract Factory 20 | ------------------- 21 | 22 | The abstract factory pattern is used to provide a client with a set of related or dependant objects. 23 | The "family" of objects created by the factory are determined at run-time. 24 | 25 | ### Example 26 | 27 | Protocols 28 | */ 29 | 30 | protocol BurgerDescribing { 31 | var ingredients: [String] { get } 32 | } 33 | 34 | struct CheeseBurger: BurgerDescribing { 35 | let ingredients: [String] 36 | } 37 | 38 | protocol BurgerMaking { 39 | func make() -> BurgerDescribing 40 | } 41 | 42 | // Number implementations with factory methods 43 | 44 | final class BigKahunaBurger: BurgerMaking { 45 | func make() -> BurgerDescribing { 46 | return CheeseBurger(ingredients: ["Cheese", "Burger", "Lettuce", "Tomato"]) 47 | } 48 | } 49 | 50 | final class JackInTheBox: BurgerMaking { 51 | func make() -> BurgerDescribing { 52 | return CheeseBurger(ingredients: ["Cheese", "Burger", "Tomato", "Onions"]) 53 | } 54 | } 55 | 56 | /*: 57 | Abstract factory 58 | */ 59 | 60 | enum BurgerFactoryType: BurgerMaking { 61 | 62 | case bigKahuna 63 | case jackInTheBox 64 | 65 | func make() -> BurgerDescribing { 66 | switch self { 67 | case .bigKahuna: 68 | return BigKahunaBurger().make() 69 | case .jackInTheBox: 70 | return JackInTheBox().make() 71 | } 72 | } 73 | } 74 | /*: 75 | ### Usage 76 | */ 77 | let bigKahuna = BurgerFactoryType.bigKahuna.make() 78 | let jackInTheBox = BurgerFactoryType.jackInTheBox.make() 79 | /*: 80 | 👷 Builder 81 | ---------- 82 | 83 | The builder pattern is used to create complex objects with constituent parts that must be created in the same order or using a specific algorithm. 84 | An external class controls the construction algorithm. 85 | 86 | ### Example 87 | */ 88 | final class DeathStarBuilder { 89 | 90 | var x: Double? 91 | var y: Double? 92 | var z: Double? 93 | 94 | typealias BuilderClosure = (DeathStarBuilder) -> () 95 | 96 | init(buildClosure: BuilderClosure) { 97 | buildClosure(self) 98 | } 99 | } 100 | 101 | struct DeathStar : CustomStringConvertible { 102 | 103 | let x: Double 104 | let y: Double 105 | let z: Double 106 | 107 | init?(builder: DeathStarBuilder) { 108 | 109 | if let x = builder.x, let y = builder.y, let z = builder.z { 110 | self.x = x 111 | self.y = y 112 | self.z = z 113 | } else { 114 | return nil 115 | } 116 | } 117 | 118 | var description:String { 119 | return "Death Star at (x:\(x) y:\(y) z:\(z))" 120 | } 121 | } 122 | /*: 123 | ### Usage 124 | */ 125 | let empire = DeathStarBuilder { builder in 126 | builder.x = 0.1 127 | builder.y = 0.2 128 | builder.z = 0.3 129 | } 130 | 131 | let deathStar = DeathStar(builder:empire) 132 | /*: 133 | 🏭 Factory Method 134 | ----------------- 135 | 136 | The factory pattern is used to replace class constructors, abstracting the process of object generation so that the type of the object instantiated can be determined at run-time. 137 | 138 | ### Example 139 | */ 140 | protocol CurrencyDescribing { 141 | var symbol: String { get } 142 | var code: String { get } 143 | } 144 | 145 | final class Euro: CurrencyDescribing { 146 | var symbol: String { 147 | return "€" 148 | } 149 | 150 | var code: String { 151 | return "EUR" 152 | } 153 | } 154 | 155 | final class UnitedStatesDolar: CurrencyDescribing { 156 | var symbol: String { 157 | return "$" 158 | } 159 | 160 | var code: String { 161 | return "USD" 162 | } 163 | } 164 | 165 | enum Country { 166 | case unitedStates 167 | case spain 168 | case uk 169 | case greece 170 | } 171 | 172 | enum CurrencyFactory { 173 | static func currency(for country: Country) -> CurrencyDescribing? { 174 | 175 | switch country { 176 | case .spain, .greece: 177 | return Euro() 178 | case .unitedStates: 179 | return UnitedStatesDolar() 180 | default: 181 | return nil 182 | } 183 | 184 | } 185 | } 186 | /*: 187 | ### Usage 188 | */ 189 | let noCurrencyCode = "No Currency Code Available" 190 | 191 | CurrencyFactory.currency(for: .greece)?.code ?? noCurrencyCode 192 | CurrencyFactory.currency(for: .spain)?.code ?? noCurrencyCode 193 | CurrencyFactory.currency(for: .unitedStates)?.code ?? noCurrencyCode 194 | CurrencyFactory.currency(for: .uk)?.code ?? noCurrencyCode 195 | /*: 196 | 🔂 Monostate 197 | ------------ 198 | 199 | The monostate pattern is another way to achieve singularity. It works through a completely different mechanism, it enforces the behavior of singularity without imposing structural constraints. 200 | So in that case, monostate saves the state as static instead of the entire instance as a singleton. 201 | [SINGLETON and MONOSTATE - Robert C. Martin](http://staff.cs.utu.fi/~jounsmed/doos_06/material/SingletonAndMonostate.pdf) 202 | 203 | ### Example: 204 | */ 205 | class Settings { 206 | 207 | enum Theme { 208 | case `default` 209 | case old 210 | case new 211 | } 212 | 213 | private static var theme: Theme? 214 | 215 | var currentTheme: Theme { 216 | get { Settings.theme ?? .default } 217 | set(newTheme) { Settings.theme = newTheme } 218 | } 219 | } 220 | /*: 221 | ### Usage: 222 | */ 223 | 224 | import SwiftUI 225 | 226 | // When change the theme 227 | let settings = Settings() // Starts using theme .old 228 | settings.currentTheme = .new // Change theme to .new 229 | 230 | // On screen 1 231 | let screenColor: Color = Settings().currentTheme == .old ? .gray : .white 232 | 233 | // On screen 2 234 | let screenTitle: String = Settings().currentTheme == .old ? "Itunes Connect" : "App Store Connect" 235 | /*: 236 | 🃏 Prototype 237 | ------------ 238 | 239 | The prototype pattern is used to instantiate a new object by copying all of the properties of an existing object, creating an independent clone. 240 | This practise is particularly useful when the construction of a new object is inefficient. 241 | 242 | ### Example 243 | */ 244 | class MoonWorker { 245 | 246 | let name: String 247 | var health: Int = 100 248 | 249 | init(name: String) { 250 | self.name = name 251 | } 252 | 253 | func clone() -> MoonWorker { 254 | return MoonWorker(name: name) 255 | } 256 | } 257 | /*: 258 | ### Usage 259 | */ 260 | let prototype = MoonWorker(name: "Sam Bell") 261 | 262 | var bell1 = prototype.clone() 263 | bell1.health = 12 264 | 265 | var bell2 = prototype.clone() 266 | bell2.health = 23 267 | 268 | var bell3 = prototype.clone() 269 | bell3.health = 0 270 | /*: 271 | 💍 Singleton 272 | ------------ 273 | 274 | The singleton pattern ensures that only one object of a particular class is ever created. 275 | All further references to objects of the singleton class refer to the same underlying instance. 276 | There are very few applications, do not overuse this pattern! 277 | 278 | ### Example: 279 | */ 280 | final class ElonMusk { 281 | 282 | static let shared = ElonMusk() 283 | 284 | private init() { 285 | // Private initialization to ensure just one instance is created. 286 | } 287 | } 288 | /*: 289 | ### Usage: 290 | */ 291 | let elon = ElonMusk.shared // There is only one Elon Musk folks. 292 | -------------------------------------------------------------------------------- /Design-Patterns.playground/Pages/Index.xcplaygroundpage/Contents.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 3 | Design Patterns implemented in Swift 5.0 4 | ======================================== 5 | 6 | A short cheat-sheet with Xcode 10.2 Playground ([Design-Patterns.playground.zip](https://raw.githubusercontent.com/ochococo/Design-Patterns-In-Swift/master/Design-Patterns.playground.zip)). 7 | 8 | ### [🇨🇳中文版](https://github.com/ochococo/Design-Patterns-In-Swift/blob/master/README-CN.md) 9 | 10 | 👷 Project started by: [@nsmeme](http://twitter.com/nsmeme) (Oktawian Chojnacki) 11 | 12 | 👷 中文版由 [@binglogo](https://twitter.com/binglogo) (棒棒彬) 整理翻译。 13 | 14 | 🚀 How to generate README, Playground and zip from source: [GENERATE.md](https://github.com/ochococo/Design-Patterns-In-Swift/blob/master/GENERATE.md) 15 | 16 | ## Table of Contents 17 | 18 | * [Behavioral](Behavioral) 19 | * [Creational](Creational) 20 | * [Structural](Structural) 21 | 22 | */ 23 | import Foundation 24 | 25 | print("Welcome!") 26 | -------------------------------------------------------------------------------- /Design-Patterns.playground/Pages/Structural.xcplaygroundpage/Contents.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 3 | Structural 4 | ========== 5 | 6 | >In software engineering, structural design patterns are design patterns that ease the design by identifying a simple way to realize relationships between entities. 7 | > 8 | >**Source:** [wikipedia.org](http://en.wikipedia.org/wiki/Structural_pattern) 9 | 10 | ## Table of Contents 11 | 12 | * [Behavioral](Behavioral) 13 | * [Creational](Creational) 14 | * [Structural](Structural) 15 | 16 | */ 17 | import Foundation 18 | /*: 19 | 🔌 Adapter 20 | ---------- 21 | 22 | The adapter pattern is used to provide a link between two otherwise incompatible types by wrapping the "adaptee" with a class that supports the interface required by the client. 23 | 24 | ### Example 25 | */ 26 | protocol NewDeathStarSuperLaserAiming { 27 | var angleV: Double { get } 28 | var angleH: Double { get } 29 | } 30 | /*: 31 | **Adaptee** 32 | */ 33 | struct OldDeathStarSuperlaserTarget { 34 | let angleHorizontal: Float 35 | let angleVertical: Float 36 | 37 | init(angleHorizontal: Float, angleVertical: Float) { 38 | self.angleHorizontal = angleHorizontal 39 | self.angleVertical = angleVertical 40 | } 41 | } 42 | /*: 43 | **Adapter** 44 | */ 45 | struct NewDeathStarSuperlaserTarget: NewDeathStarSuperLaserAiming { 46 | 47 | private let target: OldDeathStarSuperlaserTarget 48 | 49 | var angleV: Double { 50 | return Double(target.angleVertical) 51 | } 52 | 53 | var angleH: Double { 54 | return Double(target.angleHorizontal) 55 | } 56 | 57 | init(_ target: OldDeathStarSuperlaserTarget) { 58 | self.target = target 59 | } 60 | } 61 | /*: 62 | ### Usage 63 | */ 64 | let target = OldDeathStarSuperlaserTarget(angleHorizontal: 14.0, angleVertical: 12.0) 65 | let newFormat = NewDeathStarSuperlaserTarget(target) 66 | 67 | newFormat.angleH 68 | newFormat.angleV 69 | /*: 70 | 🌉 Bridge 71 | ---------- 72 | 73 | The bridge pattern is used to separate the abstract elements of a class from the implementation details, providing the means to replace the implementation details without modifying the abstraction. 74 | 75 | ### Example 76 | */ 77 | protocol Switch { 78 | var appliance: Appliance { get set } 79 | func turnOn() 80 | } 81 | 82 | protocol Appliance { 83 | func run() 84 | } 85 | 86 | final class RemoteControl: Switch { 87 | var appliance: Appliance 88 | 89 | func turnOn() { 90 | self.appliance.run() 91 | } 92 | 93 | init(appliance: Appliance) { 94 | self.appliance = appliance 95 | } 96 | } 97 | 98 | final class TV: Appliance { 99 | func run() { 100 | print("tv turned on"); 101 | } 102 | } 103 | 104 | final class VacuumCleaner: Appliance { 105 | func run() { 106 | print("vacuum cleaner turned on") 107 | } 108 | } 109 | /*: 110 | ### Usage 111 | */ 112 | let tvRemoteControl = RemoteControl(appliance: TV()) 113 | tvRemoteControl.turnOn() 114 | 115 | let fancyVacuumCleanerRemoteControl = RemoteControl(appliance: VacuumCleaner()) 116 | fancyVacuumCleanerRemoteControl.turnOn() 117 | /*: 118 | 🌿 Composite 119 | ------------- 120 | 121 | The composite pattern is used to create hierarchical, recursive tree structures of related objects where any element of the structure may be accessed and utilised in a standard manner. 122 | 123 | ### Example 124 | 125 | Component 126 | */ 127 | protocol Shape { 128 | func draw(fillColor: String) 129 | } 130 | /*: 131 | Leafs 132 | */ 133 | final class Square: Shape { 134 | func draw(fillColor: String) { 135 | print("Drawing a Square with color \(fillColor)") 136 | } 137 | } 138 | 139 | final class Circle: Shape { 140 | func draw(fillColor: String) { 141 | print("Drawing a circle with color \(fillColor)") 142 | } 143 | } 144 | 145 | /*: 146 | Composite 147 | */ 148 | final class Whiteboard: Shape { 149 | 150 | private lazy var shapes = [Shape]() 151 | 152 | init(_ shapes: Shape...) { 153 | self.shapes = shapes 154 | } 155 | 156 | func draw(fillColor: String) { 157 | for shape in self.shapes { 158 | shape.draw(fillColor: fillColor) 159 | } 160 | } 161 | } 162 | /*: 163 | ### Usage: 164 | */ 165 | var whiteboard = Whiteboard(Circle(), Square()) 166 | whiteboard.draw(fillColor: "Red") 167 | /*: 168 | 🍧 Decorator 169 | ------------ 170 | 171 | The decorator pattern is used to extend or alter the functionality of objects at run- time by wrapping them in an object of a decorator class. 172 | This provides a flexible alternative to using inheritance to modify behaviour. 173 | 174 | ### Example 175 | */ 176 | protocol CostHaving { 177 | var cost: Double { get } 178 | } 179 | 180 | protocol IngredientsHaving { 181 | var ingredients: [String] { get } 182 | } 183 | 184 | typealias BeverageDataHaving = CostHaving & IngredientsHaving 185 | 186 | struct SimpleCoffee: BeverageDataHaving { 187 | let cost: Double = 1.0 188 | let ingredients = ["Water", "Coffee"] 189 | } 190 | 191 | protocol BeverageHaving: BeverageDataHaving { 192 | var beverage: BeverageDataHaving { get } 193 | } 194 | 195 | struct Milk: BeverageHaving { 196 | 197 | let beverage: BeverageDataHaving 198 | 199 | var cost: Double { 200 | return beverage.cost + 0.5 201 | } 202 | 203 | var ingredients: [String] { 204 | return beverage.ingredients + ["Milk"] 205 | } 206 | } 207 | 208 | struct WhipCoffee: BeverageHaving { 209 | 210 | let beverage: BeverageDataHaving 211 | 212 | var cost: Double { 213 | return beverage.cost + 0.5 214 | } 215 | 216 | var ingredients: [String] { 217 | return beverage.ingredients + ["Whip"] 218 | } 219 | } 220 | /*: 221 | ### Usage: 222 | */ 223 | var someCoffee: BeverageDataHaving = SimpleCoffee() 224 | print("Cost: \(someCoffee.cost); Ingredients: \(someCoffee.ingredients)") 225 | someCoffee = Milk(beverage: someCoffee) 226 | print("Cost: \(someCoffee.cost); Ingredients: \(someCoffee.ingredients)") 227 | someCoffee = WhipCoffee(beverage: someCoffee) 228 | print("Cost: \(someCoffee.cost); Ingredients: \(someCoffee.ingredients)") 229 | /*: 230 | 🎁 Façade 231 | --------- 232 | 233 | The facade pattern is used to define a simplified interface to a more complex subsystem. 234 | 235 | ### Example 236 | */ 237 | final class Defaults { 238 | 239 | private let defaults: UserDefaults 240 | 241 | init(defaults: UserDefaults = .standard) { 242 | self.defaults = defaults 243 | } 244 | 245 | subscript(key: String) -> String? { 246 | get { 247 | return defaults.string(forKey: key) 248 | } 249 | 250 | set { 251 | defaults.set(newValue, forKey: key) 252 | } 253 | } 254 | } 255 | /*: 256 | ### Usage 257 | */ 258 | let storage = Defaults() 259 | 260 | // Store 261 | storage["Bishop"] = "Disconnect me. I’d rather be nothing" 262 | 263 | // Read 264 | storage["Bishop"] 265 | /*: 266 | ## 🍃 Flyweight 267 | The flyweight pattern is used to minimize memory usage or computational expenses by sharing as much as possible with other similar objects. 268 | ### Example 269 | */ 270 | // Instances of SpecialityCoffee will be the Flyweights 271 | struct SpecialityCoffee { 272 | let origin: String 273 | } 274 | 275 | protocol CoffeeSearching { 276 | func search(origin: String) -> SpecialityCoffee? 277 | } 278 | 279 | // Menu acts as a factory and cache for SpecialityCoffee flyweight objects 280 | final class Menu: CoffeeSearching { 281 | 282 | private var coffeeAvailable: [String: SpecialityCoffee] = [:] 283 | 284 | func search(origin: String) -> SpecialityCoffee? { 285 | if coffeeAvailable.index(forKey: origin) == nil { 286 | coffeeAvailable[origin] = SpecialityCoffee(origin: origin) 287 | } 288 | 289 | return coffeeAvailable[origin] 290 | } 291 | } 292 | 293 | final class CoffeeShop { 294 | private var orders: [Int: SpecialityCoffee] = [:] 295 | private let menu: CoffeeSearching 296 | 297 | init(menu: CoffeeSearching) { 298 | self.menu = menu 299 | } 300 | 301 | func takeOrder(origin: String, table: Int) { 302 | orders[table] = menu.search(origin: origin) 303 | } 304 | 305 | func serve() { 306 | for (table, origin) in orders { 307 | print("Serving \(origin) to table \(table)") 308 | } 309 | } 310 | } 311 | /*: 312 | ### Usage 313 | */ 314 | let coffeeShop = CoffeeShop(menu: Menu()) 315 | 316 | coffeeShop.takeOrder(origin: "Yirgacheffe, Ethiopia", table: 1) 317 | coffeeShop.takeOrder(origin: "Buziraguhindwa, Burundi", table: 3) 318 | 319 | coffeeShop.serve() 320 | /*: 321 | ☔ Protection Proxy 322 | ------------------ 323 | 324 | The proxy pattern is used to provide a surrogate or placeholder object, which references an underlying object. 325 | Protection proxy is restricting access. 326 | 327 | ### Example 328 | */ 329 | protocol DoorOpening { 330 | func open(doors: String) -> String 331 | } 332 | 333 | final class HAL9000: DoorOpening { 334 | func open(doors: String) -> String { 335 | return ("HAL9000: Affirmative, Dave. I read you. Opened \(doors).") 336 | } 337 | } 338 | 339 | final class CurrentComputer: DoorOpening { 340 | private var computer: HAL9000! 341 | 342 | func authenticate(password: String) -> Bool { 343 | 344 | guard password == "pass" else { 345 | return false 346 | } 347 | 348 | computer = HAL9000() 349 | 350 | return true 351 | } 352 | 353 | func open(doors: String) -> String { 354 | 355 | guard computer != nil else { 356 | return "Access Denied. I'm afraid I can't do that." 357 | } 358 | 359 | return computer.open(doors: doors) 360 | } 361 | } 362 | /*: 363 | ### Usage 364 | */ 365 | let computer = CurrentComputer() 366 | let podBay = "Pod Bay Doors" 367 | 368 | computer.open(doors: podBay) 369 | 370 | computer.authenticate(password: "pass") 371 | computer.open(doors: podBay) 372 | /*: 373 | 🍬 Virtual Proxy 374 | ---------------- 375 | 376 | The proxy pattern is used to provide a surrogate or placeholder object, which references an underlying object. 377 | Virtual proxy is used for loading object on demand. 378 | 379 | ### Example 380 | */ 381 | protocol HEVSuitMedicalAid { 382 | func administerMorphine() -> String 383 | } 384 | 385 | final class HEVSuit: HEVSuitMedicalAid { 386 | func administerMorphine() -> String { 387 | return "Morphine administered." 388 | } 389 | } 390 | 391 | final class HEVSuitHumanInterface: HEVSuitMedicalAid { 392 | 393 | lazy private var physicalSuit: HEVSuit = HEVSuit() 394 | 395 | func administerMorphine() -> String { 396 | return physicalSuit.administerMorphine() 397 | } 398 | } 399 | /*: 400 | ### Usage 401 | */ 402 | let humanInterface = HEVSuitHumanInterface() 403 | humanInterface.administerMorphine() 404 | -------------------------------------------------------------------------------- /Design-Patterns.playground/Pages/Structural.xcplaygroundpage/timeline.xctimeline: -------------------------------------------------------------------------------- 1 | 2 | 4 | 5 | 6 | 7 | -------------------------------------------------------------------------------- /Design-Patterns.playground/contents.xcplayground: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 3, 29 June 2007 3 | 4 | Copyright (C) 2007 Free Software Foundation, Inc. 5 | Everyone is permitted to copy and distribute verbatim copies 6 | of this license document, but changing it is not allowed. 7 | 8 | Preamble 9 | 10 | The GNU General Public License is a free, copyleft license for 11 | software and other kinds of works. 12 | 13 | The licenses for most software and other practical works are designed 14 | to take away your freedom to share and change the works. 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See the 645 | GNU General Public License for more details. 646 | 647 | You should have received a copy of the GNU General Public License 648 | along with this program. If not, see . 649 | 650 | Also add information on how to contact you by electronic and paper mail. 651 | 652 | If the program does terminal interaction, make it output a short 653 | notice like this when it starts in an interactive mode: 654 | 655 | {project} Copyright (C) {year} {fullname} 656 | This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 657 | This is free software, and you are welcome to redistribute it 658 | under certain conditions; type `show c' for details. 659 | 660 | The hypothetical commands `show w' and `show c' should show the appropriate 661 | parts of the General Public License. Of course, your program's commands 662 | might be different; for a GUI interface, you would use an "about box". 663 | 664 | You should also get your employer (if you work as a programmer) or school, 665 | if any, to sign a "copyright disclaimer" for the program, if necessary. 666 | For more information on this, and how to apply and follow the GNU GPL, see 667 | . 668 | 669 | The GNU General Public License does not permit incorporating your program 670 | into proprietary programs. If your program is a subroutine library, you 671 | may consider it more useful to permit linking proprietary applications with 672 | the library. If this is what you want to do, use the GNU Lesser General 673 | Public License instead of this License. But first, please read 674 | . -------------------------------------------------------------------------------- /PULL_REQUEST_TEMPLATE.md: -------------------------------------------------------------------------------- 1 | - [ ] Read [CONTRIBUTING.md]](https://github.com/ochococo/Design-Patterns-In-Swift/blob/master/CONTRIBUTING.md]) 2 | - [ ] Added description 3 | - [ ] Linked to and/or created issue -------------------------------------------------------------------------------- /generate-playground-cn.sh: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | 3 | # Note: I think this part is absolute garbage but it's a snapshot of my current skills with Bash. 4 | # Would love to rewrite it in Swift soon. 5 | 6 | combineSwiftCN() { 7 | cat source-cn/startComment > $2 8 | cat $1/header.md >> $2 9 | cat source-cn/contents.md >> $2 10 | cat source-cn/endComment >> $2 11 | cat source-cn/imports.swift >> $2 12 | cat $1/*.swift >> $2 13 | { rm $2 && awk '{gsub("\\*//\\*:", "", $0); print}' > $2; } < $2 14 | } 15 | 16 | move() { 17 | mv $1.swift Design-Patterns-CN.playground/Pages/$1.xcplaygroundpage/Contents.swift 18 | } 19 | 20 | playground() { 21 | combineSwiftCN source-cn/$1 $1.swift 22 | move $1 23 | } 24 | 25 | combineMarkdown() { 26 | cat $1/header.md > $2 27 | 28 | { rm $2 && awk '{gsub("\\*/", "", $0); print}' > $2; } < $2 29 | { rm $2 && awk '{gsub("/\\*:", "", $0); print}' > $2; } < $2 30 | 31 | cat source-cn/startSwiftCode >> $2 32 | cat $1/*.swift >> $2 33 | 34 | { rm $2 && awk '{gsub("\\*//\\*:", "", $0); print}' > $2; } < $2 35 | { rm $2 && awk '{gsub("\\*/", "\n```swift", $0); print}' > $2; } < $2 36 | { rm $2 && awk '{gsub("/\\*:", "```\n", $0); print}' > $2; } < $2 37 | 38 | cat source-cn/endSwiftCode >> $2 39 | 40 | { rm $2 && awk '{gsub("```swift```", "", $0); print}' > $2; } < $2 41 | 42 | cat $2 >> README-CN.md 43 | rm $2 44 | } 45 | 46 | readme() { 47 | combineMarkdown source-cn/$1 $1.md 48 | } 49 | 50 | playground Index 51 | playground Behavioral 52 | playground Creational 53 | playground Structural 54 | 55 | zip -r -X Design-Patterns-CN.playground.zip ./Design-Patterns-CN.playground 56 | 57 | echo "" > README-CN.md 58 | 59 | readme Index 60 | cat source-cn/contentsReadme.md >> README-CN.md 61 | readme Behavioral 62 | readme Creational 63 | readme Structural 64 | cat source-cn/footer.md >> README-CN.md -------------------------------------------------------------------------------- /generate-playground.sh: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | 3 | # Note: I think this part is absolute garbage but it's a snapshot of my current skills with Bash. 4 | # Would love to rewrite it in Swift soon. 5 | 6 | combineSwift() { 7 | cat source/startComment > $2 8 | cat $1/header.md >> $2 9 | cat source/contents.md >> $2 10 | cat source/endComment >> $2 11 | cat source/imports.swift >> $2 12 | cat $1/*.swift >> $2 13 | { rm $2 && awk '{gsub("\\*//\\*:", "", $0); print}' > $2; } < $2 14 | } 15 | 16 | move() { 17 | mv $1.swift Design-Patterns.playground/Pages/$1.xcplaygroundpage/Contents.swift 18 | } 19 | 20 | playground() { 21 | combineSwift source/$1 $1.swift 22 | move $1 23 | } 24 | 25 | combineMarkdown() { 26 | cat $1/header.md > $2 27 | 28 | { rm $2 && awk '{gsub("\\*/", "", $0); print}' > $2; } < $2 29 | { rm $2 && awk '{gsub("/\\*:", "", $0); print}' > $2; } < $2 30 | 31 | cat source/startSwiftCode >> $2 32 | cat $1/*.swift >> $2 33 | 34 | { rm $2 && awk '{gsub("\\*//\\*:", "", $0); print}' > $2; } < $2 35 | { rm $2 && awk '{gsub("\\*/", "\n```swift", $0); print}' > $2; } < $2 36 | { rm $2 && awk '{gsub("/\\*:", "```\n", $0); print}' > $2; } < $2 37 | 38 | cat source/endSwiftCode >> $2 39 | 40 | { rm $2 && awk '{gsub("```swift```", "", $0); print}' > $2; } < $2 41 | 42 | cat $2 >> README.md 43 | rm $2 44 | } 45 | 46 | readme() { 47 | combineMarkdown source/$1 $1.md 48 | } 49 | 50 | playground Index 51 | playground Behavioral 52 | playground Creational 53 | playground Structural 54 | 55 | zip -r -X Design-Patterns.playground.zip ./Design-Patterns.playground 56 | 57 | echo "" > README.md 58 | 59 | readme Index 60 | cat source/contentsReadme.md >> README.md 61 | readme Behavioral 62 | readme Creational 63 | readme Structural 64 | cat source/footer.md >> README.md -------------------------------------------------------------------------------- /source-cn/Index/header.md: -------------------------------------------------------------------------------- 1 | 2 | 设计模式（Swift 5.0 实现） 3 | ====================== 4 | 5 | ([Design-Patterns-CN.playground.zip](https://raw.githubusercontent.com/ochococo/Design-Patterns-In-Swift/master/Design-Patterns-CN.playground.zip)). 6 | 7 | 👷 源项目由 [@nsmeme](http://twitter.com/nsmeme) (Oktawian Chojnacki) 维护。 8 | 9 | 🇨🇳 中文版由 [@binglogo](https://twitter.com/binglogo) 整理翻译。 10 | -------------------------------------------------------------------------------- /source-cn/Index/welcome.swift: -------------------------------------------------------------------------------- 1 | 2 | print("您好！") 3 | -------------------------------------------------------------------------------- /source-cn/behavioral/chain_of_responsibility.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🐝 责任链（Chain Of Responsibility） 3 | ------------------------------ 4 | 5 | 责任链模式在面向对象程式设计里是一种软件设计模式，它包含了一些命令对象和一系列的处理对象。每一个处理对象决定它能处理哪些命令对象，它也知道如何将它不能处理的命令对象传递给该链中的下一个处理对象。 6 | 7 | ### 示例： 8 | */ 9 | 10 | protocol Withdrawing { 11 | func withdraw(amount: Int) -> Bool 12 | } 13 | 14 | final class MoneyPile: Withdrawing { 15 | 16 | let value: Int 17 | var quantity: Int 18 | var next: Withdrawing? 19 | 20 | init(value: Int, quantity: Int, next: Withdrawing?) { 21 | self.value = value 22 | self.quantity = quantity 23 | self.next = next 24 | } 25 | 26 | func withdraw(amount: Int) -> Bool { 27 | 28 | var amount = amount 29 | 30 | func canTakeSomeBill(want: Int) -> Bool { 31 | return (want / self.value) > 0 32 | } 33 | 34 | var quantity = self.quantity 35 | 36 | while canTakeSomeBill(want: amount) { 37 | 38 | if quantity == 0 { 39 | break 40 | } 41 | 42 | amount -= self.value 43 | quantity -= 1 44 | } 45 | 46 | guard amount > 0 else { 47 | return true 48 | } 49 | 50 | if let next = self.next { 51 | return next.withdraw(amount: amount) 52 | } 53 | 54 | return false 55 | } 56 | } 57 | 58 | final class ATM: Withdrawing { 59 | 60 | private var hundred: Withdrawing 61 | private var fifty: Withdrawing 62 | private var twenty: Withdrawing 63 | private var ten: Withdrawing 64 | 65 | private var startPile: Withdrawing { 66 | return self.hundred 67 | } 68 | 69 | init(hundred: Withdrawing, 70 | fifty: Withdrawing, 71 | twenty: Withdrawing, 72 | ten: Withdrawing) { 73 | 74 | self.hundred = hundred 75 | self.fifty = fifty 76 | self.twenty = twenty 77 | self.ten = ten 78 | } 79 | 80 | func withdraw(amount: Int) -> Bool { 81 | return startPile.withdraw(amount: amount) 82 | } 83 | } 84 | /*: 85 | ### 用法 86 | */ 87 | // 创建一系列的钱堆，并将其链接起来：10<20<50<100 88 | let ten = MoneyPile(value: 10, quantity: 6, next: nil) 89 | let twenty = MoneyPile(value: 20, quantity: 2, next: ten) 90 | let fifty = MoneyPile(value: 50, quantity: 2, next: twenty) 91 | let hundred = MoneyPile(value: 100, quantity: 1, next: fifty) 92 | 93 | // 创建 ATM 实例 94 | var atm = ATM(hundred: hundred, fifty: fifty, twenty: twenty, ten: ten) 95 | atm.withdraw(amount: 310) // Cannot because ATM has only 300 96 | atm.withdraw(amount: 100) // Can withdraw - 1x100 97 | -------------------------------------------------------------------------------- /source-cn/behavioral/command.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 👫 命令（Command） 3 | ------------ 4 | 命令模式是一种设计模式，它尝试以对象来代表实际行动。命令对象可以把行动(action) 及其参数封装起来，于是这些行动可以被： 5 | * 重复多次 6 | * 取消（如果该对象有实现的话） 7 | * 取消后又再重做 8 | ### 示例： 9 | */ 10 | protocol DoorCommand { 11 | func execute() -> String 12 | } 13 | 14 | final class OpenCommand: DoorCommand { 15 | let doors:String 16 | 17 | required init(doors: String) { 18 | self.doors = doors 19 | } 20 | 21 | func execute() -> String { 22 | return "Opened \(doors)" 23 | } 24 | } 25 | 26 | final class CloseCommand: DoorCommand { 27 | let doors:String 28 | 29 | required init(doors: String) { 30 | self.doors = doors 31 | } 32 | 33 | func execute() -> String { 34 | return "Closed \(doors)" 35 | } 36 | } 37 | 38 | final class HAL9000DoorsOperations { 39 | let openCommand: DoorCommand 40 | let closeCommand: DoorCommand 41 | 42 | init(doors: String) { 43 | self.openCommand = OpenCommand(doors:doors) 44 | self.closeCommand = CloseCommand(doors:doors) 45 | } 46 | 47 | func close() -> String { 48 | return closeCommand.execute() 49 | } 50 | 51 | func open() -> String { 52 | return openCommand.execute() 53 | } 54 | } 55 | /*: 56 | ### 用法 57 | */ 58 | let podBayDoors = "Pod Bay Doors" 59 | let doorModule = HAL9000DoorsOperations(doors:podBayDoors) 60 | 61 | doorModule.open() 62 | doorModule.close() 63 | -------------------------------------------------------------------------------- /source-cn/behavioral/header.md: -------------------------------------------------------------------------------- 1 | 2 | 行为型模式 3 | ======== 4 | 5 | >在软件工程中， 行为型模式为设计模式的一种类型，用来识别对象之间的常用交流模式并加以实现。如此，可在进行这些交流活动时增强弹性。 6 | > 7 | >**来源：** [维基百科](https://zh.wikipedia.org/wiki/%E8%A1%8C%E7%82%BA%E5%9E%8B%E6%A8%A1%E5%BC%8F) 8 | -------------------------------------------------------------------------------- /source-cn/behavioral/interpreter.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🎶 解释器（Interpreter） 3 | ------------------ 4 | 5 | 给定一种语言，定义他的文法的一种表示，并定义一个解释器，该解释器使用该表示来解释语言中句子。 6 | 7 | ### 示例： 8 | */ 9 | 10 | protocol IntegerExpression { 11 | func evaluate(_ context: IntegerContext) -> Int 12 | func replace(character: Character, integerExpression: IntegerExpression) -> IntegerExpression 13 | func copied() -> IntegerExpression 14 | } 15 | 16 | final class IntegerContext { 17 | private var data: [Character:Int] = [:] 18 | 19 | func lookup(name: Character) -> Int { 20 | return self.data[name]! 21 | } 22 | 23 | func assign(expression: IntegerVariableExpression, value: Int) { 24 | self.data[expression.name] = value 25 | } 26 | } 27 | 28 | final class IntegerVariableExpression: IntegerExpression { 29 | let name: Character 30 | 31 | init(name: Character) { 32 | self.name = name 33 | } 34 | 35 | func evaluate(_ context: IntegerContext) -> Int { 36 | return context.lookup(name: self.name) 37 | } 38 | 39 | func replace(character name: Character, integerExpression: IntegerExpression) -> IntegerExpression { 40 | if name == self.name { 41 | return integerExpression.copied() 42 | } else { 43 | return IntegerVariableExpression(name: self.name) 44 | } 45 | } 46 | 47 | func copied() -> IntegerExpression { 48 | return IntegerVariableExpression(name: self.name) 49 | } 50 | } 51 | 52 | final class AddExpression: IntegerExpression { 53 | private var operand1: IntegerExpression 54 | private var operand2: IntegerExpression 55 | 56 | init(op1: IntegerExpression, op2: IntegerExpression) { 57 | self.operand1 = op1 58 | self.operand2 = op2 59 | } 60 | 61 | func evaluate(_ context: IntegerContext) -> Int { 62 | return self.operand1.evaluate(context) + self.operand2.evaluate(context) 63 | } 64 | 65 | func replace(character: Character, integerExpression: IntegerExpression) -> IntegerExpression { 66 | return AddExpression(op1: operand1.replace(character: character, integerExpression: integerExpression), 67 | op2: operand2.replace(character: character, integerExpression: integerExpression)) 68 | } 69 | 70 | func copied() -> IntegerExpression { 71 | return AddExpression(op1: self.operand1, op2: self.operand2) 72 | } 73 | } 74 | /*: 75 | ### 用法 76 | */ 77 | var context = IntegerContext() 78 | 79 | var a = IntegerVariableExpression(name: "A") 80 | var b = IntegerVariableExpression(name: "B") 81 | var c = IntegerVariableExpression(name: "C") 82 | 83 | var expression = AddExpression(op1: a, op2: AddExpression(op1: b, op2: c)) // a + (b + c) 84 | 85 | context.assign(expression: a, value: 2) 86 | context.assign(expression: b, value: 1) 87 | context.assign(expression: c, value: 3) 88 | 89 | var result = expression.evaluate(context) 90 | -------------------------------------------------------------------------------- /source-cn/behavioral/iterator.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🍫 迭代器（Iterator） 3 | --------------- 4 | 5 | 迭代器模式可以让用户通过特定的接口巡访容器中的每一个元素而不用了解底层的实现。 6 | 7 | ### 示例： 8 | */ 9 | struct Novella { 10 | let name: String 11 | } 12 | 13 | struct Novellas { 14 | let novellas: [Novella] 15 | } 16 | 17 | struct NovellasIterator: IteratorProtocol { 18 | 19 | private var current = 0 20 | private let novellas: [Novella] 21 | 22 | init(novellas: [Novella]) { 23 | self.novellas = novellas 24 | } 25 | 26 | mutating func next() -> Novella? { 27 | defer { current += 1 } 28 | return novellas.count > current ? novellas[current] : nil 29 | } 30 | } 31 | 32 | extension Novellas: Sequence { 33 | func makeIterator() -> NovellasIterator { 34 | return NovellasIterator(novellas: novellas) 35 | } 36 | } 37 | /*: 38 | ### 用法 39 | */ 40 | let greatNovellas = Novellas(novellas: [Novella(name: "The Mist")] ) 41 | 42 | for novella in greatNovellas { 43 | print("I've read: \(novella)") 44 | } 45 | -------------------------------------------------------------------------------- /source-cn/behavioral/mediator.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 💐 中介者（Mediator） 3 | --------------- 4 | 5 | 用一个中介者对象封装一系列的对象交互，中介者使各对象不需要显示地相互作用，从而使耦合松散，而且可以独立地改变它们之间的交互。 6 | 7 | ### 示例： 8 | */ 9 | protocol Receiver { 10 | associatedtype MessageType 11 | func receive(message: MessageType) 12 | } 13 | 14 | protocol Sender { 15 | associatedtype MessageType 16 | associatedtype ReceiverType: Receiver 17 | 18 | var recipients: [ReceiverType] { get } 19 | 20 | func send(message: MessageType) 21 | } 22 | 23 | struct Programmer: Receiver { 24 | let name: String 25 | 26 | init(name: String) { 27 | self.name = name 28 | } 29 | 30 | func receive(message: String) { 31 | print("\(name) received: \(message)") 32 | } 33 | } 34 | 35 | final class MessageMediator: Sender { 36 | internal var recipients: [Programmer] = [] 37 | 38 | func add(recipient: Programmer) { 39 | recipients.append(recipient) 40 | } 41 | 42 | func send(message: String) { 43 | for recipient in recipients { 44 | recipient.receive(message: message) 45 | } 46 | } 47 | } 48 | 49 | /*: 50 | ### 用法 51 | */ 52 | func spamMonster(message: String, worker: MessageMediator) { 53 | worker.send(message: message) 54 | } 55 | 56 | let messagesMediator = MessageMediator() 57 | 58 | let user0 = Programmer(name: "Linus Torvalds") 59 | let user1 = Programmer(name: "Avadis 'Avie' Tevanian") 60 | messagesMediator.add(recipient: user0) 61 | messagesMediator.add(recipient: user1) 62 | 63 | spamMonster(message: "I'd Like to Add you to My Professional Network", worker: messagesMediator) 64 | 65 | -------------------------------------------------------------------------------- /source-cn/behavioral/memento.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 💾 备忘录（Memento） 3 | -------------- 4 | 5 | 在不破坏封装性的前提下，捕获一个对象的内部状态，并在该对象之外保存这个状态。这样就可以将该对象恢复到原先保存的状态 6 | 7 | ### 示例： 8 | */ 9 | typealias Memento = [String: String] 10 | /*: 11 | 发起人（Originator） 12 | */ 13 | protocol MementoConvertible { 14 | var memento: Memento { get } 15 | init?(memento: Memento) 16 | } 17 | 18 | struct GameState: MementoConvertible { 19 | 20 | private enum Keys { 21 | static let chapter = "com.valve.halflife.chapter" 22 | static let weapon = "com.valve.halflife.weapon" 23 | } 24 | 25 | var chapter: String 26 | var weapon: String 27 | 28 | init(chapter: String, weapon: String) { 29 | self.chapter = chapter 30 | self.weapon = weapon 31 | } 32 | 33 | init?(memento: Memento) { 34 | guard let mementoChapter = memento[Keys.chapter], 35 | let mementoWeapon = memento[Keys.weapon] else { 36 | return nil 37 | } 38 | 39 | chapter = mementoChapter 40 | weapon = mementoWeapon 41 | } 42 | 43 | var memento: Memento { 44 | return [ Keys.chapter: chapter, Keys.weapon: weapon ] 45 | } 46 | } 47 | /*: 48 | 管理者（Caretaker） 49 | */ 50 | enum CheckPoint { 51 | 52 | private static let defaults = UserDefaults.standard 53 | 54 | static func save(_ state: MementoConvertible, saveName: String) { 55 | defaults.set(state.memento, forKey: saveName) 56 | defaults.synchronize() 57 | } 58 | 59 | static func restore(saveName: String) -> Any? { 60 | return defaults.object(forKey: saveName) 61 | } 62 | } 63 | /*: 64 | ### 用法 65 | */ 66 | var gameState = GameState(chapter: "Black Mesa Inbound", weapon: "Crowbar") 67 | 68 | gameState.chapter = "Anomalous Materials" 69 | gameState.weapon = "Glock 17" 70 | CheckPoint.save(gameState, saveName: "gameState1") 71 | 72 | gameState.chapter = "Unforeseen Consequences" 73 | gameState.weapon = "MP5" 74 | CheckPoint.save(gameState, saveName: "gameState2") 75 | 76 | gameState.chapter = "Office Complex" 77 | gameState.weapon = "Crossbow" 78 | CheckPoint.save(gameState, saveName: "gameState3") 79 | 80 | if let memento = CheckPoint.restore(saveName: "gameState1") as? Memento { 81 | let finalState = GameState(memento: memento) 82 | dump(finalState) 83 | } 84 | -------------------------------------------------------------------------------- /source-cn/behavioral/observer.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 👓 观察者（Observer） 3 | --------------- 4 | 5 | 一个目标对象管理所有相依于它的观察者对象，并且在它本身的状态改变时主动发出通知 6 | 7 | ### 示例： 8 | */ 9 | protocol PropertyObserver : class { 10 | func willChange(propertyName: String, newPropertyValue: Any?) 11 | func didChange(propertyName: String, oldPropertyValue: Any?) 12 | } 13 | 14 | final class TestChambers { 15 | 16 | weak var observer:PropertyObserver? 17 | 18 | private let testChamberNumberName = "testChamberNumber" 19 | 20 | var testChamberNumber: Int = 0 { 21 | willSet(newValue) { 22 | observer?.willChange(propertyName: testChamberNumberName, newPropertyValue: newValue) 23 | } 24 | didSet { 25 | observer?.didChange(propertyName: testChamberNumberName, oldPropertyValue: oldValue) 26 | } 27 | } 28 | } 29 | 30 | final class Observer : PropertyObserver { 31 | func willChange(propertyName: String, newPropertyValue: Any?) { 32 | if newPropertyValue as? Int == 1 { 33 | print("Okay. Look. We both said a lot of things that you're going to regret.") 34 | } 35 | } 36 | 37 | func didChange(propertyName: String, oldPropertyValue: Any?) { 38 | if oldPropertyValue as? Int == 0 { 39 | print("Sorry about the mess. I've really let the place go since you killed me.") 40 | } 41 | } 42 | } 43 | /*: 44 | ### 用法 45 | */ 46 | var observerInstance = Observer() 47 | var testChambers = TestChambers() 48 | testChambers.observer = observerInstance 49 | testChambers.testChamberNumber += 1 50 | -------------------------------------------------------------------------------- /source-cn/behavioral/state.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🐉 状态（State） 3 | --------- 4 | 5 | 在状态模式中，对象的行为是基于它的内部状态而改变的。 6 | 这个模式允许某个类对象在运行时发生改变。 7 | 8 | ### 示例： 9 | */ 10 | final class Context { 11 | private var state: State = UnauthorizedState() 12 | 13 | var isAuthorized: Bool { 14 | get { return state.isAuthorized(context: self) } 15 | } 16 | 17 | var userId: String? { 18 | get { return state.userId(context: self) } 19 | } 20 | 21 | func changeStateToAuthorized(userId: String) { 22 | state = AuthorizedState(userId: userId) 23 | } 24 | 25 | func changeStateToUnauthorized() { 26 | state = UnauthorizedState() 27 | } 28 | } 29 | 30 | protocol State { 31 | func isAuthorized(context: Context) -> Bool 32 | func userId(context: Context) -> String? 33 | } 34 | 35 | class UnauthorizedState: State { 36 | func isAuthorized(context: Context) -> Bool { return false } 37 | 38 | func userId(context: Context) -> String? { return nil } 39 | } 40 | 41 | class AuthorizedState: State { 42 | let userId: String 43 | 44 | init(userId: String) { self.userId = userId } 45 | 46 | func isAuthorized(context: Context) -> Bool { return true } 47 | 48 | func userId(context: Context) -> String? { return userId } 49 | } 50 | /*: 51 | ### 用法 52 | */ 53 | let userContext = Context() 54 | (userContext.isAuthorized, userContext.userId) 55 | userContext.changeStateToAuthorized(userId: "admin") 56 | (userContext.isAuthorized, userContext.userId) // now logged in as "admin" 57 | userContext.changeStateToUnauthorized() 58 | (userContext.isAuthorized, userContext.userId) 59 | -------------------------------------------------------------------------------- /source-cn/behavioral/strategy.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 💡 策略（Strategy） 3 | -------------- 4 | 5 | 对象有某个行为，但是在不同的场景中，该行为有不同的实现算法。策略模式： 6 | * 定义了一族算法（业务规则）； 7 | * 封装了每个算法； 8 | * 这族的算法可互换代替（interchangeable）。 9 | 10 | ### 示例： 11 | */ 12 | 13 | struct TestSubject { 14 | let pupilDiameter: Double 15 | let blushResponse: Double 16 | let isOrganic: Bool 17 | } 18 | 19 | protocol RealnessTesting: AnyObject { 20 | func testRealness(_ testSubject: TestSubject) -> Bool 21 | } 22 | 23 | final class VoightKampffTest: RealnessTesting { 24 | func testRealness(_ testSubject: TestSubject) -> Bool { 25 | return testSubject.pupilDiameter < 30.0 || testSubject.blushResponse == 0.0 26 | } 27 | } 28 | 29 | final class GeneticTest: RealnessTesting { 30 | func testRealness(_ testSubject: TestSubject) -> Bool { 31 | return testSubject.isOrganic 32 | } 33 | } 34 | 35 | final class BladeRunner { 36 | private let strategy: RealnessTesting 37 | 38 | init(test: RealnessTesting) { 39 | self.strategy = test 40 | } 41 | 42 | func testIfAndroid(_ testSubject: TestSubject) -> Bool { 43 | return !strategy.testRealness(testSubject) 44 | } 45 | } 46 | 47 | /*: 48 | ### 用法 49 | */ 50 | 51 | let rachel = TestSubject(pupilDiameter: 30.2, 52 | blushResponse: 0.3, 53 | isOrganic: false) 54 | 55 | // Deckard is using a traditional test 56 | let deckard = BladeRunner(test: VoightKampffTest()) 57 | let isRachelAndroid = deckard.testIfAndroid(rachel) 58 | 59 | // Gaff is using a very precise method 60 | let gaff = BladeRunner(test: GeneticTest()) 61 | let isDeckardAndroid = gaff.testIfAndroid(rachel) 62 | -------------------------------------------------------------------------------- /source-cn/behavioral/template_method.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 📝 模板方法模式 3 | ----------- 4 | 5 | 模板方法模式是一种行为设计模式， 它通过父类/协议中定义了一个算法的框架， 允许子类/具体实现对象在不修改结构的情况下重写算法的特定步骤。 6 | 7 | ### 示例： 8 | */ 9 | protocol Garden { 10 | func prepareSoil() 11 | func plantSeeds() 12 | func waterPlants() 13 | func prepareGarden() 14 | } 15 | 16 | extension Garden { 17 | 18 | func prepareGarden() { 19 | prepareSoil() 20 | plantSeeds() 21 | waterPlants() 22 | } 23 | } 24 | 25 | final class RoseGarden: Garden { 26 | 27 | func prepare() { 28 | prepareGarden() 29 | } 30 | 31 | func prepareSoil() { 32 | print ("prepare soil for rose garden") 33 | } 34 | 35 | func plantSeeds() { 36 | print ("plant seeds for rose garden") 37 | } 38 | 39 | func waterPlants() { 40 | print ("water the rose garden") 41 | } 42 | } 43 | 44 | /*: 45 | ### 用法 46 | */ 47 | 48 | let roseGarden = RoseGarden() 49 | roseGarden.prepare() 50 | -------------------------------------------------------------------------------- /source-cn/behavioral/visitor.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🏃 访问者（Visitor） 3 | -------------- 4 | 5 | 封装某些作用于某种数据结构中各元素的操作，它可以在不改变数据结构的前提下定义作用于这些元素的新的操作。 6 | 7 | ### 示例： 8 | */ 9 | protocol PlanetVisitor { 10 | func visit(planet: PlanetAlderaan) 11 | func visit(planet: PlanetCoruscant) 12 | func visit(planet: PlanetTatooine) 13 | func visit(planet: MoonJedha) 14 | } 15 | 16 | protocol Planet { 17 | func accept(visitor: PlanetVisitor) 18 | } 19 | 20 | final class MoonJedha: Planet { 21 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 22 | } 23 | 24 | final class PlanetAlderaan: Planet { 25 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 26 | } 27 | 28 | final class PlanetCoruscant: Planet { 29 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 30 | } 31 | 32 | final class PlanetTatooine: Planet { 33 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 34 | } 35 | 36 | final class NameVisitor: PlanetVisitor { 37 | var name = "" 38 | 39 | func visit(planet: PlanetAlderaan) { name = "Alderaan" } 40 | func visit(planet: PlanetCoruscant) { name = "Coruscant" } 41 | func visit(planet: PlanetTatooine) { name = "Tatooine" } 42 | func visit(planet: MoonJedha) { name = "Jedha" } 43 | } 44 | 45 | /*: 46 | ### 用法 47 | */ 48 | let planets: [Planet] = [PlanetAlderaan(), PlanetCoruscant(), PlanetTatooine(), MoonJedha()] 49 | 50 | let names = planets.map { (planet: Planet) -> String in 51 | let visitor = NameVisitor() 52 | planet.accept(visitor: visitor) 53 | 54 | return visitor.name 55 | } 56 | 57 | names 58 | -------------------------------------------------------------------------------- /source-cn/contents.md: -------------------------------------------------------------------------------- 1 | 2 | ## 目录 3 | 4 | * [行为型模式](Behavioral) 5 | * [创建型模式](Creational) 6 | * [结构型模式](Structural) -------------------------------------------------------------------------------- /source-cn/contentsReadme.md: -------------------------------------------------------------------------------- 1 | 2 | ## 目录 3 | 4 | | [行为型模式](#行为型模式) | [创建型模式](#创建型模式) | [结构型模式](#结构型模式structural) | 5 | | ------------------------------------------------------------ | --------------------------------------------------------- | ------------------------------------------------------------ | 6 | | [🐝 责任链 Chain Of Responsibility](#-责任链chain-of-responsibility) | [🌰 抽象工厂 Abstract Factory](#-抽象工厂abstract-factory) | [🔌 适配器 Adapter](#-适配器adapter) | 7 | | [👫 命令 Command](#-命令command) | [👷 生成器 Builder](#-生成器builder) | [🌉 桥接 Bridge](#-桥接bridge) | 8 | | [🎶 解释器 Interpreter](#-解释器interpreter) | [🏭 工厂方法 Factory Method](#-工厂方法factory-method) | [🌿 组合 Composite](#-组合composite) | 9 | | [🍫 迭代器 Iterator](#-迭代器iterator) | [🔂 单态 Monostate](#-单态monostate) | [🍧 修饰 Decorator](#-修饰decorator) | 10 | | [💐 中介者 Mediator](#-中介者mediator) | [🃏 原型 Prototype](#-原型prototype) | [🎁 外观 Façade](#-外观facade) | 11 | | [💾 备忘录 Memento](#-备忘录memento) | [💍 单例 Singleton](#-单例singleton) | [🍃 享元 Flyweight](#-享元flyweight) | 12 | | [👓 观察者 Observer](#-观察者observer) | | [☔ 保护代理 Protection Proxy](#-保护代理模式protection-proxy) | 13 | | [🐉 状态 State](#-状态state) | | [🍬 虚拟代理 Virtual Proxy](#-虚拟代理virtual-proxy) | 14 | | [💡 策略 Strategy](#-策略strategy) | | | 15 | | [🏃 访问者 Visitor](#-访问者visitor) | | | 16 | | [📝 模板方法 Templdate Method](#-template-method) | | | 17 | 18 | -------------------------------------------------------------------------------- /source-cn/creational/abstract_factory.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🌰 抽象工厂（Abstract Factory） 3 | ------------- 4 | 5 | 抽象工厂模式提供了一种方式，可以将一组具有同一主题的单独的工厂封装起来。在正常使用中，客户端程序需要创建抽象工厂的具体实现，然后使用抽象工厂作为接口来创建这一主题的具体对象。 6 | 7 | ### 示例： 8 | 9 | 协议 10 | */ 11 | 12 | protocol BurgerDescribing { 13 | var ingredients: [String] { get } 14 | } 15 | 16 | struct CheeseBurger: BurgerDescribing { 17 | let ingredients: [String] 18 | } 19 | 20 | protocol BurgerMaking { 21 | func make() -> BurgerDescribing 22 | } 23 | 24 | // 工厂方法实现 25 | 26 | final class BigKahunaBurger: BurgerMaking { 27 | func make() -> BurgerDescribing { 28 | return CheeseBurger(ingredients: ["Cheese", "Burger", "Lettuce", "Tomato"]) 29 | } 30 | } 31 | 32 | final class JackInTheBox: BurgerMaking { 33 | func make() -> BurgerDescribing { 34 | return CheeseBurger(ingredients: ["Cheese", "Burger", "Tomato", "Onions"]) 35 | } 36 | } 37 | 38 | /*: 39 | 抽象工厂 40 | */ 41 | 42 | enum BurgerFactoryType: BurgerMaking { 43 | 44 | case bigKahuna 45 | case jackInTheBox 46 | 47 | func make() -> BurgerDescribing { 48 | switch self { 49 | case .bigKahuna: 50 | return BigKahunaBurger().make() 51 | case .jackInTheBox: 52 | return JackInTheBox().make() 53 | } 54 | } 55 | } 56 | /*: 57 | ### 用法 58 | */ 59 | let bigKahuna = BurgerFactoryType.bigKahuna.make() 60 | let jackInTheBox = BurgerFactoryType.jackInTheBox.make() 61 | -------------------------------------------------------------------------------- /source-cn/creational/builder.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 👷 生成器（Builder） 3 | -------------- 4 | 5 | 一种对象构建模式。它可以将复杂对象的建造过程抽象出来（抽象类别），使这个抽象过程的不同实现方法可以构造出不同表现（属性）的对象。 6 | 7 | ### 示例： 8 | */ 9 | final class DeathStarBuilder { 10 | 11 | var x: Double? 12 | var y: Double? 13 | var z: Double? 14 | 15 | typealias BuilderClosure = (DeathStarBuilder) -> () 16 | 17 | init(buildClosure: BuilderClosure) { 18 | buildClosure(self) 19 | } 20 | } 21 | 22 | struct DeathStar : CustomStringConvertible { 23 | 24 | let x: Double 25 | let y: Double 26 | let z: Double 27 | 28 | init?(builder: DeathStarBuilder) { 29 | 30 | if let x = builder.x, let y = builder.y, let z = builder.z { 31 | self.x = x 32 | self.y = y 33 | self.z = z 34 | } else { 35 | return nil 36 | } 37 | } 38 | 39 | var description:String { 40 | return "Death Star at (x:\(x) y:\(y) z:\(z))" 41 | } 42 | } 43 | /*: 44 | ### 用法 45 | */ 46 | let empire = DeathStarBuilder { builder in 47 | builder.x = 0.1 48 | builder.y = 0.2 49 | builder.z = 0.3 50 | } 51 | 52 | let deathStar = DeathStar(builder:empire) 53 | -------------------------------------------------------------------------------- /source-cn/creational/factory.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🏭 工厂方法（Factory Method） 3 | ----------------------- 4 | 5 | 定义一个创建对象的接口，但让实现这个接口的类来决定实例化哪个类。工厂方法让类的实例化推迟到子类中进行。 6 | 7 | ### 示例： 8 | */ 9 | protocol CurrencyDescribing { 10 | var symbol: String { get } 11 | var code: String { get } 12 | } 13 | 14 | final class Euro: CurrencyDescribing { 15 | var symbol: String { 16 | return "€" 17 | } 18 | 19 | var code: String { 20 | return "EUR" 21 | } 22 | } 23 | 24 | final class UnitedStatesDolar: CurrencyDescribing { 25 | var symbol: String { 26 | return "$" 27 | } 28 | 29 | var code: String { 30 | return "USD" 31 | } 32 | } 33 | 34 | enum Country { 35 | case unitedStates 36 | case spain 37 | case uk 38 | case greece 39 | } 40 | 41 | enum CurrencyFactory { 42 | static func currency(for country: Country) -> CurrencyDescribing? { 43 | 44 | switch country { 45 | case .spain, .greece: 46 | return Euro() 47 | case .unitedStates: 48 | return UnitedStatesDolar() 49 | default: 50 | return nil 51 | } 52 | 53 | } 54 | } 55 | /*: 56 | ### 用法 57 | */ 58 | let noCurrencyCode = "No Currency Code Available" 59 | 60 | CurrencyFactory.currency(for: .greece)?.code ?? noCurrencyCode 61 | CurrencyFactory.currency(for: .spain)?.code ?? noCurrencyCode 62 | CurrencyFactory.currency(for: .unitedStates)?.code ?? noCurrencyCode 63 | CurrencyFactory.currency(for: .uk)?.code ?? noCurrencyCode 64 | -------------------------------------------------------------------------------- /source-cn/creational/header.md: -------------------------------------------------------------------------------- 1 | 2 | 创建型模式 3 | ======== 4 | 5 | > 创建型模式是处理对象创建的设计模式，试图根据实际情况使用合适的方式创建对象。基本的对象创建方式可能会导致设计上的问题，或增加设计的复杂度。创建型模式通过以某种方式控制对象的创建来解决问题。 6 | > 7 | >**来源：** [维基百科](https://zh.wikipedia.org/wiki/%E5%89%B5%E5%BB%BA%E5%9E%8B%E6%A8%A1%E5%BC%8F) 8 | -------------------------------------------------------------------------------- /source-cn/creational/monostate.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🔂 单态（Monostate） 3 | ------------ 4 | 5 | 单态模式是实现单一共享的另一种方法。不同于单例模式，它通过完全不同的机制，在不限制构造方法的情况下实现单一共享特性。 6 | 因此，在这种情况下，单态会将状态保存为静态，而不是将整个实例保存为单例。 7 | [单例和单态 - Robert C. Martin](http://staff.cs.utu.fi/~jounsmed/doos_06/material/SingletonAndMonostate.pdf) 8 | 9 | ### 示例: 10 | */ 11 | class Settings { 12 | 13 | enum Theme { 14 | case `default` 15 | case old 16 | case new 17 | } 18 | 19 | private static var theme: Theme? 20 | 21 | var currentTheme: Theme { 22 | get { Settings.theme ?? .default } 23 | set(newTheme) { Settings.theme = newTheme } 24 | } 25 | } 26 | /*: 27 | ### 用法: 28 | */ 29 | import SwiftUI 30 | 31 | // 改变主题 32 | let settings = Settings() // 开始使用主题 .old 33 | settings.currentTheme = .new // 改变主题为 .new 34 | 35 | // 界面一 36 | let screenColor: Color = Settings().currentTheme == .old ? .gray : .white 37 | 38 | // 界面二 39 | let screenTitle: String = Settings().currentTheme == .old ? "Itunes Connect" : "App Store Connect" 40 | -------------------------------------------------------------------------------- /source-cn/creational/prototype.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🃏 原型（Prototype） 3 | -------------- 4 | 5 | 通过“复制”一个已经存在的实例来返回新的实例,而不是新建实例。被复制的实例就是我们所称的“原型”，这个原型是可定制的。 6 | 7 | ### 示例： 8 | */ 9 | class MoonWorker { 10 | 11 | let name: String 12 | var health: Int = 100 13 | 14 | init(name: String) { 15 | self.name = name 16 | } 17 | 18 | func clone() -> MoonWorker { 19 | return MoonWorker(name: name) 20 | } 21 | } 22 | /*: 23 | ### 用法 24 | */ 25 | let prototype = MoonWorker(name: "Sam Bell") 26 | 27 | var bell1 = prototype.clone() 28 | bell1.health = 12 29 | 30 | var bell2 = prototype.clone() 31 | bell2.health = 23 32 | 33 | var bell3 = prototype.clone() 34 | bell3.health = 0 35 | -------------------------------------------------------------------------------- /source-cn/creational/singleton.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 💍 单例（Singleton） 3 | -------------- 4 | 5 | 单例对象的类必须保证只有一个实例存在。许多时候整个系统只需要拥有一个的全局对象，这样有利于我们协调系统整体的行为 6 | 7 | ### 示例： 8 | */ 9 | final class ElonMusk { 10 | 11 | static let shared = ElonMusk() 12 | 13 | private init() { 14 | // Private initialization to ensure just one instance is created. 15 | } 16 | } 17 | /*: 18 | ### 用法 19 | */ 20 | let elon = ElonMusk.shared // There is only one Elon Musk folks. 21 | -------------------------------------------------------------------------------- /source-cn/endComment: -------------------------------------------------------------------------------- 1 | 2 | */ -------------------------------------------------------------------------------- /source-cn/endSwiftCode: -------------------------------------------------------------------------------- 1 | ``` 2 | 3 | -------------------------------------------------------------------------------- /source-cn/footer.md: -------------------------------------------------------------------------------- 1 | 2 | Info 3 | ==== 4 | 5 | 📖 Descriptions from: [Gang of Four Design Patterns Reference Sheet](http://www.blackwasp.co.uk/GangOfFour.aspx) 6 | -------------------------------------------------------------------------------- /source-cn/imports.swift: -------------------------------------------------------------------------------- 1 | 2 | import Foundation 3 | -------------------------------------------------------------------------------- /source-cn/startComment: -------------------------------------------------------------------------------- 1 | /*: 2 | -------------------------------------------------------------------------------- /source-cn/startSwiftCode: -------------------------------------------------------------------------------- 1 | 2 | 3 | ```swift -------------------------------------------------------------------------------- /source-cn/structural/adapter.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🔌 适配器（Adapter） 3 | -------------- 4 | 5 | 适配器模式有时候也称包装样式或者包装(wrapper)。将一个类的接口转接成用户所期待的。一个适配使得因接口不兼容而不能在一起工作的类工作在一起，做法是将类自己的接口包裹在一个已存在的类中。 6 | 7 | ### 示例： 8 | */ 9 | protocol NewDeathStarSuperLaserAiming { 10 | var angleV: Double { get } 11 | var angleH: Double { get } 12 | } 13 | /*: 14 | **被适配者** 15 | */ 16 | struct OldDeathStarSuperlaserTarget { 17 | let angleHorizontal: Float 18 | let angleVertical: Float 19 | 20 | init(angleHorizontal: Float, angleVertical: Float) { 21 | self.angleHorizontal = angleHorizontal 22 | self.angleVertical = angleVertical 23 | } 24 | } 25 | /*: 26 | **适配器** 27 | */ 28 | struct NewDeathStarSuperlaserTarget: NewDeathStarSuperLaserAiming { 29 | 30 | private let target: OldDeathStarSuperlaserTarget 31 | 32 | var angleV: Double { 33 | return Double(target.angleVertical) 34 | } 35 | 36 | var angleH: Double { 37 | return Double(target.angleHorizontal) 38 | } 39 | 40 | init(_ target: OldDeathStarSuperlaserTarget) { 41 | self.target = target 42 | } 43 | } 44 | /*: 45 | ### 用法 46 | */ 47 | let target = OldDeathStarSuperlaserTarget(angleHorizontal: 14.0, angleVertical: 12.0) 48 | let newFormat = NewDeathStarSuperlaserTarget(target) 49 | 50 | newFormat.angleH 51 | newFormat.angleV 52 | -------------------------------------------------------------------------------- /source-cn/structural/bridge.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🌉 桥接（Bridge） 3 | ----------- 4 | 5 | 桥接模式将抽象部分与实现部分分离，使它们都可以独立的变化。 6 | 7 | ### 示例： 8 | */ 9 | protocol Switch { 10 | var appliance: Appliance { get set } 11 | func turnOn() 12 | } 13 | 14 | protocol Appliance { 15 | func run() 16 | } 17 | 18 | final class RemoteControl: Switch { 19 | var appliance: Appliance 20 | 21 | func turnOn() { 22 | self.appliance.run() 23 | } 24 | 25 | init(appliance: Appliance) { 26 | self.appliance = appliance 27 | } 28 | } 29 | 30 | final class TV: Appliance { 31 | func run() { 32 | print("tv turned on"); 33 | } 34 | } 35 | 36 | final class VacuumCleaner: Appliance { 37 | func run() { 38 | print("vacuum cleaner turned on") 39 | } 40 | } 41 | /*: 42 | ### 用法 43 | */ 44 | let tvRemoteControl = RemoteControl(appliance: TV()) 45 | tvRemoteControl.turnOn() 46 | 47 | let fancyVacuumCleanerRemoteControl = RemoteControl(appliance: VacuumCleaner()) 48 | fancyVacuumCleanerRemoteControl.turnOn() 49 | -------------------------------------------------------------------------------- /source-cn/structural/composite.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🌿 组合（Composite） 3 | -------------- 4 | 5 | 将对象组合成树形结构以表示‘部分-整体’的层次结构。组合模式使得用户对单个对象和组合对象的使用具有一致性。 6 | 7 | ### 示例： 8 | 9 | 组件（Component） 10 | */ 11 | protocol Shape { 12 | func draw(fillColor: String) 13 | } 14 | /*: 15 | 叶子节点（Leafs） 16 | */ 17 | final class Square: Shape { 18 | func draw(fillColor: String) { 19 | print("Drawing a Square with color \(fillColor)") 20 | } 21 | } 22 | 23 | final class Circle: Shape { 24 | func draw(fillColor: String) { 25 | print("Drawing a circle with color \(fillColor)") 26 | } 27 | } 28 | 29 | /*: 30 | 组合 31 | */ 32 | final class Whiteboard: Shape { 33 | 34 | private lazy var shapes = [Shape]() 35 | 36 | init(_ shapes: Shape...) { 37 | self.shapes = shapes 38 | } 39 | 40 | func draw(fillColor: String) { 41 | for shape in self.shapes { 42 | shape.draw(fillColor: fillColor) 43 | } 44 | } 45 | } 46 | /*: 47 | ### 用法 48 | */ 49 | var whiteboard = Whiteboard(Circle(), Square()) 50 | whiteboard.draw(fillColor: "Red") 51 | -------------------------------------------------------------------------------- /source-cn/structural/decorator.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🍧 修饰（Decorator） 3 | -------------- 4 | 5 | 修饰模式，是面向对象编程领域中，一种动态地往一个类中添加新的行为的设计模式。 6 | 就功能而言，修饰模式相比生成子类更为灵活，这样可以给某个对象而不是整个类添加一些功能。 7 | 8 | ### 示例： 9 | */ 10 | protocol CostHaving { 11 | var cost: Double { get } 12 | } 13 | 14 | protocol IngredientsHaving { 15 | var ingredients: [String] { get } 16 | } 17 | 18 | typealias BeverageDataHaving = CostHaving & IngredientsHaving 19 | 20 | struct SimpleCoffee: BeverageDataHaving { 21 | let cost: Double = 1.0 22 | let ingredients = ["Water", "Coffee"] 23 | } 24 | 25 | protocol BeverageHaving: BeverageDataHaving { 26 | var beverage: BeverageDataHaving { get } 27 | } 28 | 29 | struct Milk: BeverageHaving { 30 | 31 | let beverage: BeverageDataHaving 32 | 33 | var cost: Double { 34 | return beverage.cost + 0.5 35 | } 36 | 37 | var ingredients: [String] { 38 | return beverage.ingredients + ["Milk"] 39 | } 40 | } 41 | 42 | struct WhipCoffee: BeverageHaving { 43 | 44 | let beverage: BeverageDataHaving 45 | 46 | var cost: Double { 47 | return beverage.cost + 0.5 48 | } 49 | 50 | var ingredients: [String] { 51 | return beverage.ingredients + ["Whip"] 52 | } 53 | } 54 | /*: 55 | ### 用法 56 | */ 57 | var someCoffee: BeverageDataHaving = SimpleCoffee() 58 | print("Cost: \(someCoffee.cost); Ingredients: \(someCoffee.ingredients)") 59 | someCoffee = Milk(beverage: someCoffee) 60 | print("Cost: \(someCoffee.cost); Ingredients: \(someCoffee.ingredients)") 61 | someCoffee = WhipCoffee(beverage: someCoffee) 62 | print("Cost: \(someCoffee.cost); Ingredients: \(someCoffee.ingredients)") 63 | -------------------------------------------------------------------------------- /source-cn/structural/facade.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🎁 外观（Facade） 3 | ----------- 4 | 5 | 外观模式为子系统中的一组接口提供一个统一的高层接口，使得子系统更容易使用。 6 | 7 | ### 示例： 8 | */ 9 | final class Defaults { 10 | 11 | private let defaults: UserDefaults 12 | 13 | init(defaults: UserDefaults = .standard) { 14 | self.defaults = defaults 15 | } 16 | 17 | subscript(key: String) -> String? { 18 | get { 19 | return defaults.string(forKey: key) 20 | } 21 | 22 | set { 23 | defaults.set(newValue, forKey: key) 24 | } 25 | } 26 | } 27 | /*: 28 | ### 用法 29 | */ 30 | let storage = Defaults() 31 | 32 | // Store 33 | storage["Bishop"] = "Disconnect me. I’d rather be nothing" 34 | 35 | // Read 36 | storage["Bishop"] 37 | -------------------------------------------------------------------------------- /source-cn/structural/flyweight.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🍃 享元（Flyweight） 3 | -------------- 4 | 5 | 使用共享物件，用来尽可能减少内存使用量以及分享资讯给尽可能多的相似物件；它适合用于当大量物件只是重复因而导致无法令人接受的使用大量内存。 6 | 7 | ### 示例： 8 | */ 9 | // 特指咖啡生成的对象会是享元 10 | struct SpecialityCoffee { 11 | let origin: String 12 | } 13 | 14 | protocol CoffeeSearching { 15 | func search(origin: String) -> SpecialityCoffee? 16 | } 17 | 18 | // 菜单充当特制咖啡享元对象的工厂和缓存 19 | final class Menu: CoffeeSearching { 20 | 21 | private var coffeeAvailable: [String: SpecialityCoffee] = [:] 22 | 23 | func search(origin: String) -> SpecialityCoffee? { 24 | if coffeeAvailable.index(forKey: origin) == nil { 25 | coffeeAvailable[origin] = SpecialityCoffee(origin: origin) 26 | } 27 | 28 | return coffeeAvailable[origin] 29 | } 30 | } 31 | 32 | final class CoffeeShop { 33 | private var orders: [Int: SpecialityCoffee] = [:] 34 | private let menu: CoffeeSearching 35 | 36 | init(menu: CoffeeSearching) { 37 | self.menu = menu 38 | } 39 | 40 | func takeOrder(origin: String, table: Int) { 41 | orders[table] = menu.search(origin: origin) 42 | } 43 | 44 | func serve() { 45 | for (table, origin) in orders { 46 | print("Serving \(origin) to table \(table)") 47 | } 48 | } 49 | } 50 | /*: 51 | ### 用法 52 | */ 53 | let coffeeShop = CoffeeShop(menu: Menu()) 54 | 55 | coffeeShop.takeOrder(origin: "Yirgacheffe, Ethiopia", table: 1) 56 | coffeeShop.takeOrder(origin: "Buziraguhindwa, Burundi", table: 3) 57 | 58 | coffeeShop.serve() 59 | -------------------------------------------------------------------------------- /source-cn/structural/header.md: -------------------------------------------------------------------------------- 1 | 2 | 结构型模式（Structural） 3 | ==================== 4 | 5 | > 在软件工程中结构型模式是设计模式，借由一以贯之的方式来了解元件间的关系，以简化设计。 6 | > 7 | >**来源：** [维基百科](https://zh.wikipedia.org/wiki/%E7%B5%90%E6%A7%8B%E5%9E%8B%E6%A8%A1%E5%BC%8F) 8 | -------------------------------------------------------------------------------- /source-cn/structural/protection_proxy.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | ☔ 保护代理模式（Protection Proxy） 3 | ------------------ 4 | 5 | 在代理模式中，创建一个类代表另一个底层类的功能。 6 | 保护代理用于限制访问。 7 | 8 | ### 示例： 9 | */ 10 | protocol DoorOpening { 11 | func open(doors: String) -> String 12 | } 13 | 14 | final class HAL9000: DoorOpening { 15 | func open(doors: String) -> String { 16 | return ("HAL9000: Affirmative, Dave. I read you. Opened \(doors).") 17 | } 18 | } 19 | 20 | final class CurrentComputer: DoorOpening { 21 | private var computer: HAL9000! 22 | 23 | func authenticate(password: String) -> Bool { 24 | 25 | guard password == "pass" else { 26 | return false 27 | } 28 | 29 | computer = HAL9000() 30 | 31 | return true 32 | } 33 | 34 | func open(doors: String) -> String { 35 | 36 | guard computer != nil else { 37 | return "Access Denied. I'm afraid I can't do that." 38 | } 39 | 40 | return computer.open(doors: doors) 41 | } 42 | } 43 | /*: 44 | ### 用法 45 | */ 46 | let computer = CurrentComputer() 47 | let podBay = "Pod Bay Doors" 48 | 49 | computer.open(doors: podBay) 50 | 51 | computer.authenticate(password: "pass") 52 | computer.open(doors: podBay) 53 | -------------------------------------------------------------------------------- /source-cn/structural/virtual_proxy.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🍬 虚拟代理（Virtual Proxy） 3 | ---------------- 4 | 5 | 在代理模式中，创建一个类代表另一个底层类的功能。 6 | 虚拟代理用于对象的需时加载。 7 | 8 | ### 示例： 9 | */ 10 | protocol HEVSuitMedicalAid { 11 | func administerMorphine() -> String 12 | } 13 | 14 | final class HEVSuit: HEVSuitMedicalAid { 15 | func administerMorphine() -> String { 16 | return "Morphine administered." 17 | } 18 | } 19 | 20 | final class HEVSuitHumanInterface: HEVSuitMedicalAid { 21 | 22 | lazy private var physicalSuit: HEVSuit = HEVSuit() 23 | 24 | func administerMorphine() -> String { 25 | return physicalSuit.administerMorphine() 26 | } 27 | } 28 | /*: 29 | ### 用法 30 | */ 31 | let humanInterface = HEVSuitHumanInterface() 32 | humanInterface.administerMorphine() 33 | -------------------------------------------------------------------------------- /source/Index/header.md: -------------------------------------------------------------------------------- 1 | 2 | Design Patterns implemented in Swift 5.0 3 | ======================================== 4 | 5 | A short cheat-sheet with Xcode 10.2 Playground ([Design-Patterns.playground.zip](https://raw.githubusercontent.com/ochococo/Design-Patterns-In-Swift/master/Design-Patterns.playground.zip)). 6 | 7 | ### [🇨🇳中文版](https://github.com/ochococo/Design-Patterns-In-Swift/blob/master/README-CN.md) 8 | 9 | 👷 Project started by: [@nsmeme](http://twitter.com/nsmeme) (Oktawian Chojnacki) 10 | 11 | 👷 中文版由 [@binglogo](https://twitter.com/binglogo) (棒棒彬) 整理翻译。 12 | 13 | 🚀 How to generate README, Playground and zip from source: [GENERATE.md](https://github.com/ochococo/Design-Patterns-In-Swift/blob/master/GENERATE.md) 14 | -------------------------------------------------------------------------------- /source/Index/welcome.swift: -------------------------------------------------------------------------------- 1 | 2 | print("Welcome!") 3 | -------------------------------------------------------------------------------- /source/behavioral/chain_of_responsibility.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🐝 Chain Of Responsibility 3 | -------------------------- 4 | 5 | The chain of responsibility pattern is used to process varied requests, each of which may be dealt with by a different handler. 6 | 7 | ### Example: 8 | */ 9 | 10 | protocol Withdrawing { 11 | func withdraw(amount: Int) -> Bool 12 | } 13 | 14 | final class MoneyPile: Withdrawing { 15 | 16 | let value: Int 17 | var quantity: Int 18 | var next: Withdrawing? 19 | 20 | init(value: Int, quantity: Int, next: Withdrawing?) { 21 | self.value = value 22 | self.quantity = quantity 23 | self.next = next 24 | } 25 | 26 | func withdraw(amount: Int) -> Bool { 27 | 28 | var amount = amount 29 | 30 | func canTakeSomeBill(want: Int) -> Bool { 31 | return (want / self.value) > 0 32 | } 33 | 34 | var quantity = self.quantity 35 | 36 | while canTakeSomeBill(want: amount) { 37 | 38 | if quantity == 0 { 39 | break 40 | } 41 | 42 | amount -= self.value 43 | quantity -= 1 44 | } 45 | 46 | guard amount > 0 else { 47 | return true 48 | } 49 | 50 | if let next = self.next { 51 | return next.withdraw(amount: amount) 52 | } 53 | 54 | return false 55 | } 56 | } 57 | 58 | final class ATM: Withdrawing { 59 | 60 | private var hundred: Withdrawing 61 | private var fifty: Withdrawing 62 | private var twenty: Withdrawing 63 | private var ten: Withdrawing 64 | 65 | private var startPile: Withdrawing { 66 | return self.hundred 67 | } 68 | 69 | init(hundred: Withdrawing, 70 | fifty: Withdrawing, 71 | twenty: Withdrawing, 72 | ten: Withdrawing) { 73 | 74 | self.hundred = hundred 75 | self.fifty = fifty 76 | self.twenty = twenty 77 | self.ten = ten 78 | } 79 | 80 | func withdraw(amount: Int) -> Bool { 81 | return startPile.withdraw(amount: amount) 82 | } 83 | } 84 | /*: 85 | ### Usage 86 | */ 87 | // Create piles of money and link them together 10 < 20 < 50 < 100.** 88 | let ten = MoneyPile(value: 10, quantity: 6, next: nil) 89 | let twenty = MoneyPile(value: 20, quantity: 2, next: ten) 90 | let fifty = MoneyPile(value: 50, quantity: 2, next: twenty) 91 | let hundred = MoneyPile(value: 100, quantity: 1, next: fifty) 92 | 93 | // Build ATM. 94 | var atm = ATM(hundred: hundred, fifty: fifty, twenty: twenty, ten: ten) 95 | atm.withdraw(amount: 310) // Cannot because ATM has only 300 96 | atm.withdraw(amount: 100) // Can withdraw - 1x100 97 | -------------------------------------------------------------------------------- /source/behavioral/command.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 👫 Command 3 | ---------- 4 | 5 | The command pattern is used to express a request, including the call to be made and all of its required parameters, in a command object. The command may then be executed immediately or held for later use. 6 | 7 | ### Example: 8 | */ 9 | protocol DoorCommand { 10 | func execute() -> String 11 | } 12 | 13 | final class OpenCommand: DoorCommand { 14 | let doors:String 15 | 16 | required init(doors: String) { 17 | self.doors = doors 18 | } 19 | 20 | func execute() -> String { 21 | return "Opened \(doors)" 22 | } 23 | } 24 | 25 | final class CloseCommand: DoorCommand { 26 | let doors:String 27 | 28 | required init(doors: String) { 29 | self.doors = doors 30 | } 31 | 32 | func execute() -> String { 33 | return "Closed \(doors)" 34 | } 35 | } 36 | 37 | final class HAL9000DoorsOperations { 38 | let openCommand: DoorCommand 39 | let closeCommand: DoorCommand 40 | 41 | init(doors: String) { 42 | self.openCommand = OpenCommand(doors:doors) 43 | self.closeCommand = CloseCommand(doors:doors) 44 | } 45 | 46 | func close() -> String { 47 | return closeCommand.execute() 48 | } 49 | 50 | func open() -> String { 51 | return openCommand.execute() 52 | } 53 | } 54 | /*: 55 | ### Usage: 56 | */ 57 | let podBayDoors = "Pod Bay Doors" 58 | let doorModule = HAL9000DoorsOperations(doors:podBayDoors) 59 | 60 | doorModule.open() 61 | doorModule.close() 62 | -------------------------------------------------------------------------------- /source/behavioral/header.md: -------------------------------------------------------------------------------- 1 | 2 | Behavioral 3 | ========== 4 | 5 | >In software engineering, behavioral design patterns are design patterns that identify common communication patterns between objects and realize these patterns. By doing so, these patterns increase flexibility in carrying out this communication. 6 | > 7 | >**Source:** [wikipedia.org](http://en.wikipedia.org/wiki/Behavioral_pattern) 8 | -------------------------------------------------------------------------------- /source/behavioral/interpreter.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🎶 Interpreter 3 | -------------- 4 | 5 | The interpreter pattern is used to evaluate sentences in a language. 6 | 7 | ### Example 8 | */ 9 | 10 | protocol IntegerExpression { 11 | func evaluate(_ context: IntegerContext) -> Int 12 | func replace(character: Character, integerExpression: IntegerExpression) -> IntegerExpression 13 | func copied() -> IntegerExpression 14 | } 15 | 16 | final class IntegerContext { 17 | private var data: [Character:Int] = [:] 18 | 19 | func lookup(name: Character) -> Int { 20 | return self.data[name]! 21 | } 22 | 23 | func assign(expression: IntegerVariableExpression, value: Int) { 24 | self.data[expression.name] = value 25 | } 26 | } 27 | 28 | final class IntegerVariableExpression: IntegerExpression { 29 | let name: Character 30 | 31 | init(name: Character) { 32 | self.name = name 33 | } 34 | 35 | func evaluate(_ context: IntegerContext) -> Int { 36 | return context.lookup(name: self.name) 37 | } 38 | 39 | func replace(character name: Character, integerExpression: IntegerExpression) -> IntegerExpression { 40 | if name == self.name { 41 | return integerExpression.copied() 42 | } else { 43 | return IntegerVariableExpression(name: self.name) 44 | } 45 | } 46 | 47 | func copied() -> IntegerExpression { 48 | return IntegerVariableExpression(name: self.name) 49 | } 50 | } 51 | 52 | final class AddExpression: IntegerExpression { 53 | private var operand1: IntegerExpression 54 | private var operand2: IntegerExpression 55 | 56 | init(op1: IntegerExpression, op2: IntegerExpression) { 57 | self.operand1 = op1 58 | self.operand2 = op2 59 | } 60 | 61 | func evaluate(_ context: IntegerContext) -> Int { 62 | return self.operand1.evaluate(context) + self.operand2.evaluate(context) 63 | } 64 | 65 | func replace(character: Character, integerExpression: IntegerExpression) -> IntegerExpression { 66 | return AddExpression(op1: operand1.replace(character: character, integerExpression: integerExpression), 67 | op2: operand2.replace(character: character, integerExpression: integerExpression)) 68 | } 69 | 70 | func copied() -> IntegerExpression { 71 | return AddExpression(op1: self.operand1, op2: self.operand2) 72 | } 73 | } 74 | /*: 75 | ### Usage 76 | */ 77 | var context = IntegerContext() 78 | 79 | var a = IntegerVariableExpression(name: "A") 80 | var b = IntegerVariableExpression(name: "B") 81 | var c = IntegerVariableExpression(name: "C") 82 | 83 | var expression = AddExpression(op1: a, op2: AddExpression(op1: b, op2: c)) // a + (b + c) 84 | 85 | context.assign(expression: a, value: 2) 86 | context.assign(expression: b, value: 1) 87 | context.assign(expression: c, value: 3) 88 | 89 | var result = expression.evaluate(context) 90 | -------------------------------------------------------------------------------- /source/behavioral/iterator.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🍫 Iterator 3 | ----------- 4 | 5 | The iterator pattern is used to provide a standard interface for traversing a collection of items in an aggregate object without the need to understand its underlying structure. 6 | 7 | ### Example: 8 | */ 9 | struct Novella { 10 | let name: String 11 | } 12 | 13 | struct Novellas { 14 | let novellas: [Novella] 15 | } 16 | 17 | struct NovellasIterator: IteratorProtocol { 18 | 19 | private var current = 0 20 | private let novellas: [Novella] 21 | 22 | init(novellas: [Novella]) { 23 | self.novellas = novellas 24 | } 25 | 26 | mutating func next() -> Novella? { 27 | defer { current += 1 } 28 | return novellas.count > current ? novellas[current] : nil 29 | } 30 | } 31 | 32 | extension Novellas: Sequence { 33 | func makeIterator() -> NovellasIterator { 34 | return NovellasIterator(novellas: novellas) 35 | } 36 | } 37 | /*: 38 | ### Usage 39 | */ 40 | let greatNovellas = Novellas(novellas: [Novella(name: "The Mist")] ) 41 | 42 | for novella in greatNovellas { 43 | print("I've read: \(novella)") 44 | } 45 | -------------------------------------------------------------------------------- /source/behavioral/mediator.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 💐 Mediator 3 | ----------- 4 | 5 | The mediator pattern is used to reduce coupling between classes that communicate with each other. Instead of classes communicating directly, and thus requiring knowledge of their implementation, the classes send messages via a mediator object. 6 | 7 | ### Example 8 | */ 9 | protocol Receiver { 10 | associatedtype MessageType 11 | func receive(message: MessageType) 12 | } 13 | 14 | protocol Sender { 15 | associatedtype MessageType 16 | associatedtype ReceiverType: Receiver 17 | 18 | var recipients: [ReceiverType] { get } 19 | 20 | func send(message: MessageType) 21 | } 22 | 23 | struct Programmer: Receiver { 24 | let name: String 25 | 26 | init(name: String) { 27 | self.name = name 28 | } 29 | 30 | func receive(message: String) { 31 | print("\(name) received: \(message)") 32 | } 33 | } 34 | 35 | final class MessageMediator: Sender { 36 | internal var recipients: [Programmer] = [] 37 | 38 | func add(recipient: Programmer) { 39 | recipients.append(recipient) 40 | } 41 | 42 | func send(message: String) { 43 | for recipient in recipients { 44 | recipient.receive(message: message) 45 | } 46 | } 47 | } 48 | 49 | /*: 50 | ### Usage 51 | */ 52 | func spamMonster(message: String, worker: MessageMediator) { 53 | worker.send(message: message) 54 | } 55 | 56 | let messagesMediator = MessageMediator() 57 | 58 | let user0 = Programmer(name: "Linus Torvalds") 59 | let user1 = Programmer(name: "Avadis 'Avie' Tevanian") 60 | messagesMediator.add(recipient: user0) 61 | messagesMediator.add(recipient: user1) 62 | 63 | spamMonster(message: "I'd Like to Add you to My Professional Network", worker: messagesMediator) 64 | 65 | -------------------------------------------------------------------------------- /source/behavioral/memento.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 💾 Memento 3 | ---------- 4 | 5 | The memento pattern is used to capture the current state of an object and store it in such a manner that it can be restored at a later time without breaking the rules of encapsulation. 6 | 7 | ### Example 8 | */ 9 | typealias Memento = [String: String] 10 | /*: 11 | Originator 12 | */ 13 | protocol MementoConvertible { 14 | var memento: Memento { get } 15 | init?(memento: Memento) 16 | } 17 | 18 | struct GameState: MementoConvertible { 19 | 20 | private enum Keys { 21 | static let chapter = "com.valve.halflife.chapter" 22 | static let weapon = "com.valve.halflife.weapon" 23 | } 24 | 25 | var chapter: String 26 | var weapon: String 27 | 28 | init(chapter: String, weapon: String) { 29 | self.chapter = chapter 30 | self.weapon = weapon 31 | } 32 | 33 | init?(memento: Memento) { 34 | guard let mementoChapter = memento[Keys.chapter], 35 | let mementoWeapon = memento[Keys.weapon] else { 36 | return nil 37 | } 38 | 39 | chapter = mementoChapter 40 | weapon = mementoWeapon 41 | } 42 | 43 | var memento: Memento { 44 | return [ Keys.chapter: chapter, Keys.weapon: weapon ] 45 | } 46 | } 47 | /*: 48 | Caretaker 49 | */ 50 | enum CheckPoint { 51 | 52 | private static let defaults = UserDefaults.standard 53 | 54 | static func save(_ state: MementoConvertible, saveName: String) { 55 | defaults.set(state.memento, forKey: saveName) 56 | defaults.synchronize() 57 | } 58 | 59 | static func restore(saveName: String) -> Any? { 60 | return defaults.object(forKey: saveName) 61 | } 62 | } 63 | /*: 64 | ### Usage 65 | */ 66 | var gameState = GameState(chapter: "Black Mesa Inbound", weapon: "Crowbar") 67 | 68 | gameState.chapter = "Anomalous Materials" 69 | gameState.weapon = "Glock 17" 70 | CheckPoint.save(gameState, saveName: "gameState1") 71 | 72 | gameState.chapter = "Unforeseen Consequences" 73 | gameState.weapon = "MP5" 74 | CheckPoint.save(gameState, saveName: "gameState2") 75 | 76 | gameState.chapter = "Office Complex" 77 | gameState.weapon = "Crossbow" 78 | CheckPoint.save(gameState, saveName: "gameState3") 79 | 80 | if let memento = CheckPoint.restore(saveName: "gameState1") as? Memento { 81 | let finalState = GameState(memento: memento) 82 | dump(finalState) 83 | } 84 | -------------------------------------------------------------------------------- /source/behavioral/observer.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 👓 Observer 3 | ----------- 4 | 5 | The observer pattern is used to allow an object to publish changes to its state. 6 | Other objects subscribe to be immediately notified of any changes. 7 | 8 | ### Example 9 | */ 10 | protocol PropertyObserver : class { 11 | func willChange(propertyName: String, newPropertyValue: Any?) 12 | func didChange(propertyName: String, oldPropertyValue: Any?) 13 | } 14 | 15 | final class TestChambers { 16 | 17 | weak var observer:PropertyObserver? 18 | 19 | private let testChamberNumberName = "testChamberNumber" 20 | 21 | var testChamberNumber: Int = 0 { 22 | willSet(newValue) { 23 | observer?.willChange(propertyName: testChamberNumberName, newPropertyValue: newValue) 24 | } 25 | didSet { 26 | observer?.didChange(propertyName: testChamberNumberName, oldPropertyValue: oldValue) 27 | } 28 | } 29 | } 30 | 31 | final class Observer : PropertyObserver { 32 | func willChange(propertyName: String, newPropertyValue: Any?) { 33 | if newPropertyValue as? Int == 1 { 34 | print("Okay. Look. We both said a lot of things that you're going to regret.") 35 | } 36 | } 37 | 38 | func didChange(propertyName: String, oldPropertyValue: Any?) { 39 | if oldPropertyValue as? Int == 0 { 40 | print("Sorry about the mess. I've really let the place go since you killed me.") 41 | } 42 | } 43 | } 44 | /*: 45 | ### Usage 46 | */ 47 | var observerInstance = Observer() 48 | var testChambers = TestChambers() 49 | testChambers.observer = observerInstance 50 | testChambers.testChamberNumber += 1 51 | -------------------------------------------------------------------------------- /source/behavioral/state.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🐉 State 3 | --------- 4 | 5 | The state pattern is used to alter the behaviour of an object as its internal state changes. 6 | The pattern allows the class for an object to apparently change at run-time. 7 | 8 | ### Example 9 | */ 10 | final class Context { 11 | private var state: State = UnauthorizedState() 12 | 13 | var isAuthorized: Bool { 14 | get { return state.isAuthorized(context: self) } 15 | } 16 | 17 | var userId: String? { 18 | get { return state.userId(context: self) } 19 | } 20 | 21 | func changeStateToAuthorized(userId: String) { 22 | state = AuthorizedState(userId: userId) 23 | } 24 | 25 | func changeStateToUnauthorized() { 26 | state = UnauthorizedState() 27 | } 28 | } 29 | 30 | protocol State { 31 | func isAuthorized(context: Context) -> Bool 32 | func userId(context: Context) -> String? 33 | } 34 | 35 | class UnauthorizedState: State { 36 | func isAuthorized(context: Context) -> Bool { return false } 37 | 38 | func userId(context: Context) -> String? { return nil } 39 | } 40 | 41 | class AuthorizedState: State { 42 | let userId: String 43 | 44 | init(userId: String) { self.userId = userId } 45 | 46 | func isAuthorized(context: Context) -> Bool { return true } 47 | 48 | func userId(context: Context) -> String? { return userId } 49 | } 50 | /*: 51 | ### Usage 52 | */ 53 | let userContext = Context() 54 | (userContext.isAuthorized, userContext.userId) 55 | userContext.changeStateToAuthorized(userId: "admin") 56 | (userContext.isAuthorized, userContext.userId) // now logged in as "admin" 57 | userContext.changeStateToUnauthorized() 58 | (userContext.isAuthorized, userContext.userId) 59 | -------------------------------------------------------------------------------- /source/behavioral/strategy.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 💡 Strategy 3 | ----------- 4 | 5 | The strategy pattern is used to create an interchangeable family of algorithms from which the required process is chosen at run-time. 6 | 7 | ### Example 8 | */ 9 | 10 | struct TestSubject { 11 | let pupilDiameter: Double 12 | let blushResponse: Double 13 | let isOrganic: Bool 14 | } 15 | 16 | protocol RealnessTesting: AnyObject { 17 | func testRealness(_ testSubject: TestSubject) -> Bool 18 | } 19 | 20 | final class VoightKampffTest: RealnessTesting { 21 | func testRealness(_ testSubject: TestSubject) -> Bool { 22 | return testSubject.pupilDiameter < 30.0 || testSubject.blushResponse == 0.0 23 | } 24 | } 25 | 26 | final class GeneticTest: RealnessTesting { 27 | func testRealness(_ testSubject: TestSubject) -> Bool { 28 | return testSubject.isOrganic 29 | } 30 | } 31 | 32 | final class BladeRunner { 33 | private let strategy: RealnessTesting 34 | 35 | init(test: RealnessTesting) { 36 | self.strategy = test 37 | } 38 | 39 | func testIfAndroid(_ testSubject: TestSubject) -> Bool { 40 | return !strategy.testRealness(testSubject) 41 | } 42 | } 43 | 44 | /*: 45 | ### Usage 46 | */ 47 | 48 | let rachel = TestSubject(pupilDiameter: 30.2, 49 | blushResponse: 0.3, 50 | isOrganic: false) 51 | 52 | // Deckard is using a traditional test 53 | let deckard = BladeRunner(test: VoightKampffTest()) 54 | let isRachelAndroid = deckard.testIfAndroid(rachel) 55 | 56 | // Gaff is using a very precise method 57 | let gaff = BladeRunner(test: GeneticTest()) 58 | let isDeckardAndroid = gaff.testIfAndroid(rachel) 59 | -------------------------------------------------------------------------------- /source/behavioral/template_method.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 📝 Template Method 3 | ----------- 4 | 5 | The template method pattern defines the steps of an algorithm and allows the redefinition of one or more of these steps. In this way, the template method protects the algorithm, the order of execution and provides abstract methods that can be implemented by concrete types. 6 | 7 | ### Example 8 | */ 9 | protocol Garden { 10 | func prepareSoil() 11 | func plantSeeds() 12 | func waterPlants() 13 | func prepareGarden() 14 | } 15 | 16 | extension Garden { 17 | 18 | func prepareGarden() { 19 | prepareSoil() 20 | plantSeeds() 21 | waterPlants() 22 | } 23 | } 24 | 25 | final class RoseGarden: Garden { 26 | 27 | func prepare() { 28 | prepareGarden() 29 | } 30 | 31 | func prepareSoil() { 32 | print ("prepare soil for rose garden") 33 | } 34 | 35 | func plantSeeds() { 36 | print ("plant seeds for rose garden") 37 | } 38 | 39 | func waterPlants() { 40 | print ("water the rose garden") 41 | } 42 | } 43 | 44 | /*: 45 | ### Usage 46 | */ 47 | 48 | let roseGarden = RoseGarden() 49 | roseGarden.prepare() 50 | -------------------------------------------------------------------------------- /source/behavioral/visitor.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🏃 Visitor 3 | ---------- 4 | 5 | The visitor pattern is used to separate a relatively complex set of structured data classes from the functionality that may be performed upon the data that they hold. 6 | 7 | ### Example 8 | */ 9 | protocol PlanetVisitor { 10 | func visit(planet: PlanetAlderaan) 11 | func visit(planet: PlanetCoruscant) 12 | func visit(planet: PlanetTatooine) 13 | func visit(planet: MoonJedha) 14 | } 15 | 16 | protocol Planet { 17 | func accept(visitor: PlanetVisitor) 18 | } 19 | 20 | final class MoonJedha: Planet { 21 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 22 | } 23 | 24 | final class PlanetAlderaan: Planet { 25 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 26 | } 27 | 28 | final class PlanetCoruscant: Planet { 29 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 30 | } 31 | 32 | final class PlanetTatooine: Planet { 33 | func accept(visitor: PlanetVisitor) { visitor.visit(planet: self) } 34 | } 35 | 36 | final class NameVisitor: PlanetVisitor { 37 | var name = "" 38 | 39 | func visit(planet: PlanetAlderaan) { name = "Alderaan" } 40 | func visit(planet: PlanetCoruscant) { name = "Coruscant" } 41 | func visit(planet: PlanetTatooine) { name = "Tatooine" } 42 | func visit(planet: MoonJedha) { name = "Jedha" } 43 | } 44 | 45 | /*: 46 | ### Usage 47 | */ 48 | let planets: [Planet] = [PlanetAlderaan(), PlanetCoruscant(), PlanetTatooine(), MoonJedha()] 49 | 50 | let names = planets.map { (planet: Planet) -> String in 51 | let visitor = NameVisitor() 52 | planet.accept(visitor: visitor) 53 | 54 | return visitor.name 55 | } 56 | 57 | names 58 | -------------------------------------------------------------------------------- /source/contents.md: -------------------------------------------------------------------------------- 1 | 2 | ## Table of Contents 3 | 4 | * [Behavioral](Behavioral) 5 | * [Creational](Creational) 6 | * [Structural](Structural) 7 | -------------------------------------------------------------------------------- /source/contentsReadme.md: -------------------------------------------------------------------------------- 1 | 2 | ## Table of Contents 3 | 4 | | [Behavioral](#behavioral) | [Creational](#creational) | [Structural](#structural) | 5 | | ------------------------------------------------------ | ---------------------------------------- | ---------------------------------------- | 6 | | [🐝 Chain Of Responsibility](#-chain-of-responsibility) | [🌰 Abstract Factory](#-abstract-factory) | [🔌 Adapter](#-adapter) | 7 | | [👫 Command](#-command) | [👷 Builder](#-builder) | [🌉 Bridge](#-bridge) | 8 | | [🎶 Interpreter](#-interpreter) | [🏭 Factory Method](#-factory-method) | [🌿 Composite](#-composite) | 9 | | [🍫 Iterator](#-iterator) | [🔂 Monostate](#-monostate) | [🍧 Decorator](#-decorator) | 10 | | [💐 Mediator](#-mediator) | [🃏 Prototype](#-prototype) | [🎁 Façade](#-fa-ade) | 11 | | [💾 Memento](#-memento) | [💍 Singleton](#-singleton) | [🍃 Flyweight](#-flyweight) | 12 | | [👓 Observer](#-observer) | | [☔ Protection Proxy](#-protection-proxy) | 13 | | [🐉 State](#-state) | | [🍬 Virtual Proxy](#-virtual-proxy) | 14 | | [💡 Strategy](#-strategy) | | | 15 | | [🏃 Visitor](#-visitor) | | | 16 | | [📝 Template Method](#-template-method) | | | 17 | 18 | -------------------------------------------------------------------------------- /source/creational/abstract_factory.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🌰 Abstract Factory 3 | ------------------- 4 | 5 | The abstract factory pattern is used to provide a client with a set of related or dependant objects. 6 | The "family" of objects created by the factory are determined at run-time. 7 | 8 | ### Example 9 | 10 | Protocols 11 | */ 12 | 13 | protocol BurgerDescribing { 14 | var ingredients: [String] { get } 15 | } 16 | 17 | struct CheeseBurger: BurgerDescribing { 18 | let ingredients: [String] 19 | } 20 | 21 | protocol BurgerMaking { 22 | func make() -> BurgerDescribing 23 | } 24 | 25 | // Number implementations with factory methods 26 | 27 | final class BigKahunaBurger: BurgerMaking { 28 | func make() -> BurgerDescribing { 29 | return CheeseBurger(ingredients: ["Cheese", "Burger", "Lettuce", "Tomato"]) 30 | } 31 | } 32 | 33 | final class JackInTheBox: BurgerMaking { 34 | func make() -> BurgerDescribing { 35 | return CheeseBurger(ingredients: ["Cheese", "Burger", "Tomato", "Onions"]) 36 | } 37 | } 38 | 39 | /*: 40 | Abstract factory 41 | */ 42 | 43 | enum BurgerFactoryType: BurgerMaking { 44 | 45 | case bigKahuna 46 | case jackInTheBox 47 | 48 | func make() -> BurgerDescribing { 49 | switch self { 50 | case .bigKahuna: 51 | return BigKahunaBurger().make() 52 | case .jackInTheBox: 53 | return JackInTheBox().make() 54 | } 55 | } 56 | } 57 | /*: 58 | ### Usage 59 | */ 60 | let bigKahuna = BurgerFactoryType.bigKahuna.make() 61 | let jackInTheBox = BurgerFactoryType.jackInTheBox.make() 62 | -------------------------------------------------------------------------------- /source/creational/builder.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 👷 Builder 3 | ---------- 4 | 5 | The builder pattern is used to create complex objects with constituent parts that must be created in the same order or using a specific algorithm. 6 | An external class controls the construction algorithm. 7 | 8 | ### Example 9 | */ 10 | final class DeathStarBuilder { 11 | 12 | var x: Double? 13 | var y: Double? 14 | var z: Double? 15 | 16 | typealias BuilderClosure = (DeathStarBuilder) -> () 17 | 18 | init(buildClosure: BuilderClosure) { 19 | buildClosure(self) 20 | } 21 | } 22 | 23 | struct DeathStar : CustomStringConvertible { 24 | 25 | let x: Double 26 | let y: Double 27 | let z: Double 28 | 29 | init?(builder: DeathStarBuilder) { 30 | 31 | if let x = builder.x, let y = builder.y, let z = builder.z { 32 | self.x = x 33 | self.y = y 34 | self.z = z 35 | } else { 36 | return nil 37 | } 38 | } 39 | 40 | var description:String { 41 | return "Death Star at (x:\(x) y:\(y) z:\(z))" 42 | } 43 | } 44 | /*: 45 | ### Usage 46 | */ 47 | let empire = DeathStarBuilder { builder in 48 | builder.x = 0.1 49 | builder.y = 0.2 50 | builder.z = 0.3 51 | } 52 | 53 | let deathStar = DeathStar(builder:empire) 54 | -------------------------------------------------------------------------------- /source/creational/factory.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🏭 Factory Method 3 | ----------------- 4 | 5 | The factory pattern is used to replace class constructors, abstracting the process of object generation so that the type of the object instantiated can be determined at run-time. 6 | 7 | ### Example 8 | */ 9 | protocol CurrencyDescribing { 10 | var symbol: String { get } 11 | var code: String { get } 12 | } 13 | 14 | final class Euro: CurrencyDescribing { 15 | var symbol: String { 16 | return "€" 17 | } 18 | 19 | var code: String { 20 | return "EUR" 21 | } 22 | } 23 | 24 | final class UnitedStatesDolar: CurrencyDescribing { 25 | var symbol: String { 26 | return "$" 27 | } 28 | 29 | var code: String { 30 | return "USD" 31 | } 32 | } 33 | 34 | enum Country { 35 | case unitedStates 36 | case spain 37 | case uk 38 | case greece 39 | } 40 | 41 | enum CurrencyFactory { 42 | static func currency(for country: Country) -> CurrencyDescribing? { 43 | 44 | switch country { 45 | case .spain, .greece: 46 | return Euro() 47 | case .unitedStates: 48 | return UnitedStatesDolar() 49 | default: 50 | return nil 51 | } 52 | 53 | } 54 | } 55 | /*: 56 | ### Usage 57 | */ 58 | let noCurrencyCode = "No Currency Code Available" 59 | 60 | CurrencyFactory.currency(for: .greece)?.code ?? noCurrencyCode 61 | CurrencyFactory.currency(for: .spain)?.code ?? noCurrencyCode 62 | CurrencyFactory.currency(for: .unitedStates)?.code ?? noCurrencyCode 63 | CurrencyFactory.currency(for: .uk)?.code ?? noCurrencyCode 64 | -------------------------------------------------------------------------------- /source/creational/header.md: -------------------------------------------------------------------------------- 1 | 2 | Creational 3 | ========== 4 | 5 | > In software engineering, creational design patterns are design patterns that deal with object creation mechanisms, trying to create objects in a manner suitable to the situation. The basic form of object creation could result in design problems or added complexity to the design. Creational design patterns solve this problem by somehow controlling this object creation. 6 | > 7 | >**Source:** [wikipedia.org](http://en.wikipedia.org/wiki/Creational_pattern) 8 | -------------------------------------------------------------------------------- /source/creational/monostate.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🔂 Monostate 3 | ------------ 4 | 5 | The monostate pattern is another way to achieve singularity. It works through a completely different mechanism, it enforces the behavior of singularity without imposing structural constraints. 6 | So in that case, monostate saves the state as static instead of the entire instance as a singleton. 7 | [SINGLETON and MONOSTATE - Robert C. Martin](http://staff.cs.utu.fi/~jounsmed/doos_06/material/SingletonAndMonostate.pdf) 8 | 9 | ### Example: 10 | */ 11 | class Settings { 12 | 13 | enum Theme { 14 | case `default` 15 | case old 16 | case new 17 | } 18 | 19 | private static var theme: Theme? 20 | 21 | var currentTheme: Theme { 22 | get { Settings.theme ?? .default } 23 | set(newTheme) { Settings.theme = newTheme } 24 | } 25 | } 26 | /*: 27 | ### Usage: 28 | */ 29 | 30 | import SwiftUI 31 | 32 | // When change the theme 33 | let settings = Settings() // Starts using theme .old 34 | settings.currentTheme = .new // Change theme to .new 35 | 36 | // On screen 1 37 | let screenColor: Color = Settings().currentTheme == .old ? .gray : .white 38 | 39 | // On screen 2 40 | let screenTitle: String = Settings().currentTheme == .old ? "Itunes Connect" : "App Store Connect" 41 | -------------------------------------------------------------------------------- /source/creational/prototype.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🃏 Prototype 3 | ------------ 4 | 5 | The prototype pattern is used to instantiate a new object by copying all of the properties of an existing object, creating an independent clone. 6 | This practise is particularly useful when the construction of a new object is inefficient. 7 | 8 | ### Example 9 | */ 10 | class MoonWorker { 11 | 12 | let name: String 13 | var health: Int = 100 14 | 15 | init(name: String) { 16 | self.name = name 17 | } 18 | 19 | func clone() -> MoonWorker { 20 | return MoonWorker(name: name) 21 | } 22 | } 23 | /*: 24 | ### Usage 25 | */ 26 | let prototype = MoonWorker(name: "Sam Bell") 27 | 28 | var bell1 = prototype.clone() 29 | bell1.health = 12 30 | 31 | var bell2 = prototype.clone() 32 | bell2.health = 23 33 | 34 | var bell3 = prototype.clone() 35 | bell3.health = 0 36 | -------------------------------------------------------------------------------- /source/creational/singleton.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 💍 Singleton 3 | ------------ 4 | 5 | The singleton pattern ensures that only one object of a particular class is ever created. 6 | All further references to objects of the singleton class refer to the same underlying instance. 7 | There are very few applications, do not overuse this pattern! 8 | 9 | ### Example: 10 | */ 11 | final class ElonMusk { 12 | 13 | static let shared = ElonMusk() 14 | 15 | private init() { 16 | // Private initialization to ensure just one instance is created. 17 | } 18 | } 19 | /*: 20 | ### Usage: 21 | */ 22 | let elon = ElonMusk.shared // There is only one Elon Musk folks. 23 | -------------------------------------------------------------------------------- /source/endComment: -------------------------------------------------------------------------------- 1 | 2 | */ -------------------------------------------------------------------------------- /source/endSwiftCode: -------------------------------------------------------------------------------- 1 | ``` 2 | 3 | -------------------------------------------------------------------------------- /source/footer.md: -------------------------------------------------------------------------------- 1 | 2 | Info 3 | ==== 4 | 5 | 📖 Descriptions from: [Gang of Four Design Patterns Reference Sheet](http://www.blackwasp.co.uk/GangOfFour.aspx) 6 | -------------------------------------------------------------------------------- /source/imports.swift: -------------------------------------------------------------------------------- 1 | 2 | import Foundation 3 | -------------------------------------------------------------------------------- /source/startComment: -------------------------------------------------------------------------------- 1 | /*: 2 | -------------------------------------------------------------------------------- /source/startSwiftCode: -------------------------------------------------------------------------------- 1 | 2 | 3 | ```swift -------------------------------------------------------------------------------- /source/structural/adapter.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🔌 Adapter 3 | ---------- 4 | 5 | The adapter pattern is used to provide a link between two otherwise incompatible types by wrapping the "adaptee" with a class that supports the interface required by the client. 6 | 7 | ### Example 8 | */ 9 | protocol NewDeathStarSuperLaserAiming { 10 | var angleV: Double { get } 11 | var angleH: Double { get } 12 | } 13 | /*: 14 | **Adaptee** 15 | */ 16 | struct OldDeathStarSuperlaserTarget { 17 | let angleHorizontal: Float 18 | let angleVertical: Float 19 | 20 | init(angleHorizontal: Float, angleVertical: Float) { 21 | self.angleHorizontal = angleHorizontal 22 | self.angleVertical = angleVertical 23 | } 24 | } 25 | /*: 26 | **Adapter** 27 | */ 28 | struct NewDeathStarSuperlaserTarget: NewDeathStarSuperLaserAiming { 29 | 30 | private let target: OldDeathStarSuperlaserTarget 31 | 32 | var angleV: Double { 33 | return Double(target.angleVertical) 34 | } 35 | 36 | var angleH: Double { 37 | return Double(target.angleHorizontal) 38 | } 39 | 40 | init(_ target: OldDeathStarSuperlaserTarget) { 41 | self.target = target 42 | } 43 | } 44 | /*: 45 | ### Usage 46 | */ 47 | let target = OldDeathStarSuperlaserTarget(angleHorizontal: 14.0, angleVertical: 12.0) 48 | let newFormat = NewDeathStarSuperlaserTarget(target) 49 | 50 | newFormat.angleH 51 | newFormat.angleV 52 | -------------------------------------------------------------------------------- /source/structural/bridge.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🌉 Bridge 3 | ---------- 4 | 5 | The bridge pattern is used to separate the abstract elements of a class from the implementation details, providing the means to replace the implementation details without modifying the abstraction. 6 | 7 | ### Example 8 | */ 9 | protocol Switch { 10 | var appliance: Appliance { get set } 11 | func turnOn() 12 | } 13 | 14 | protocol Appliance { 15 | func run() 16 | } 17 | 18 | final class RemoteControl: Switch { 19 | var appliance: Appliance 20 | 21 | func turnOn() { 22 | self.appliance.run() 23 | } 24 | 25 | init(appliance: Appliance) { 26 | self.appliance = appliance 27 | } 28 | } 29 | 30 | final class TV: Appliance { 31 | func run() { 32 | print("tv turned on"); 33 | } 34 | } 35 | 36 | final class VacuumCleaner: Appliance { 37 | func run() { 38 | print("vacuum cleaner turned on") 39 | } 40 | } 41 | /*: 42 | ### Usage 43 | */ 44 | let tvRemoteControl = RemoteControl(appliance: TV()) 45 | tvRemoteControl.turnOn() 46 | 47 | let fancyVacuumCleanerRemoteControl = RemoteControl(appliance: VacuumCleaner()) 48 | fancyVacuumCleanerRemoteControl.turnOn() 49 | -------------------------------------------------------------------------------- /source/structural/composite.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🌿 Composite 3 | ------------- 4 | 5 | The composite pattern is used to create hierarchical, recursive tree structures of related objects where any element of the structure may be accessed and utilised in a standard manner. 6 | 7 | ### Example 8 | 9 | Component 10 | */ 11 | protocol Shape { 12 | func draw(fillColor: String) 13 | } 14 | /*: 15 | Leafs 16 | */ 17 | final class Square: Shape { 18 | func draw(fillColor: String) { 19 | print("Drawing a Square with color \(fillColor)") 20 | } 21 | } 22 | 23 | final class Circle: Shape { 24 | func draw(fillColor: String) { 25 | print("Drawing a circle with color \(fillColor)") 26 | } 27 | } 28 | 29 | /*: 30 | Composite 31 | */ 32 | final class Whiteboard: Shape { 33 | 34 | private lazy var shapes = [Shape]() 35 | 36 | init(_ shapes: Shape...) { 37 | self.shapes = shapes 38 | } 39 | 40 | func draw(fillColor: String) { 41 | for shape in self.shapes { 42 | shape.draw(fillColor: fillColor) 43 | } 44 | } 45 | } 46 | /*: 47 | ### Usage: 48 | */ 49 | var whiteboard = Whiteboard(Circle(), Square()) 50 | whiteboard.draw(fillColor: "Red") 51 | -------------------------------------------------------------------------------- /source/structural/decorator.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🍧 Decorator 3 | ------------ 4 | 5 | The decorator pattern is used to extend or alter the functionality of objects at run- time by wrapping them in an object of a decorator class. 6 | This provides a flexible alternative to using inheritance to modify behaviour. 7 | 8 | ### Example 9 | */ 10 | protocol CostHaving { 11 | var cost: Double { get } 12 | } 13 | 14 | protocol IngredientsHaving { 15 | var ingredients: [String] { get } 16 | } 17 | 18 | typealias BeverageDataHaving = CostHaving & IngredientsHaving 19 | 20 | struct SimpleCoffee: BeverageDataHaving { 21 | let cost: Double = 1.0 22 | let ingredients = ["Water", "Coffee"] 23 | } 24 | 25 | protocol BeverageHaving: BeverageDataHaving { 26 | var beverage: BeverageDataHaving { get } 27 | } 28 | 29 | struct Milk: BeverageHaving { 30 | 31 | let beverage: BeverageDataHaving 32 | 33 | var cost: Double { 34 | return beverage.cost + 0.5 35 | } 36 | 37 | var ingredients: [String] { 38 | return beverage.ingredients + ["Milk"] 39 | } 40 | } 41 | 42 | struct WhipCoffee: BeverageHaving { 43 | 44 | let beverage: BeverageDataHaving 45 | 46 | var cost: Double { 47 | return beverage.cost + 0.5 48 | } 49 | 50 | var ingredients: [String] { 51 | return beverage.ingredients + ["Whip"] 52 | } 53 | } 54 | /*: 55 | ### Usage: 56 | */ 57 | var someCoffee: BeverageDataHaving = SimpleCoffee() 58 | print("Cost: \(someCoffee.cost); Ingredients: \(someCoffee.ingredients)") 59 | someCoffee = Milk(beverage: someCoffee) 60 | print("Cost: \(someCoffee.cost); Ingredients: \(someCoffee.ingredients)") 61 | someCoffee = WhipCoffee(beverage: someCoffee) 62 | print("Cost: \(someCoffee.cost); Ingredients: \(someCoffee.ingredients)") 63 | -------------------------------------------------------------------------------- /source/structural/facade.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🎁 Façade 3 | --------- 4 | 5 | The facade pattern is used to define a simplified interface to a more complex subsystem. 6 | 7 | ### Example 8 | */ 9 | final class Defaults { 10 | 11 | private let defaults: UserDefaults 12 | 13 | init(defaults: UserDefaults = .standard) { 14 | self.defaults = defaults 15 | } 16 | 17 | subscript(key: String) -> String? { 18 | get { 19 | return defaults.string(forKey: key) 20 | } 21 | 22 | set { 23 | defaults.set(newValue, forKey: key) 24 | } 25 | } 26 | } 27 | /*: 28 | ### Usage 29 | */ 30 | let storage = Defaults() 31 | 32 | // Store 33 | storage["Bishop"] = "Disconnect me. I’d rather be nothing" 34 | 35 | // Read 36 | storage["Bishop"] 37 | -------------------------------------------------------------------------------- /source/structural/flyweight.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | ## 🍃 Flyweight 3 | The flyweight pattern is used to minimize memory usage or computational expenses by sharing as much as possible with other similar objects. 4 | ### Example 5 | */ 6 | // Instances of SpecialityCoffee will be the Flyweights 7 | struct SpecialityCoffee { 8 | let origin: String 9 | } 10 | 11 | protocol CoffeeSearching { 12 | func search(origin: String) -> SpecialityCoffee? 13 | } 14 | 15 | // Menu acts as a factory and cache for SpecialityCoffee flyweight objects 16 | final class Menu: CoffeeSearching { 17 | 18 | private var coffeeAvailable: [String: SpecialityCoffee] = [:] 19 | 20 | func search(origin: String) -> SpecialityCoffee? { 21 | if coffeeAvailable.index(forKey: origin) == nil { 22 | coffeeAvailable[origin] = SpecialityCoffee(origin: origin) 23 | } 24 | 25 | return coffeeAvailable[origin] 26 | } 27 | } 28 | 29 | final class CoffeeShop { 30 | private var orders: [Int: SpecialityCoffee] = [:] 31 | private let menu: CoffeeSearching 32 | 33 | init(menu: CoffeeSearching) { 34 | self.menu = menu 35 | } 36 | 37 | func takeOrder(origin: String, table: Int) { 38 | orders[table] = menu.search(origin: origin) 39 | } 40 | 41 | func serve() { 42 | for (table, origin) in orders { 43 | print("Serving \(origin) to table \(table)") 44 | } 45 | } 46 | } 47 | /*: 48 | ### Usage 49 | */ 50 | let coffeeShop = CoffeeShop(menu: Menu()) 51 | 52 | coffeeShop.takeOrder(origin: "Yirgacheffe, Ethiopia", table: 1) 53 | coffeeShop.takeOrder(origin: "Buziraguhindwa, Burundi", table: 3) 54 | 55 | coffeeShop.serve() 56 | -------------------------------------------------------------------------------- /source/structural/header.md: -------------------------------------------------------------------------------- 1 | 2 | Structural 3 | ========== 4 | 5 | >In software engineering, structural design patterns are design patterns that ease the design by identifying a simple way to realize relationships between entities. 6 | > 7 | >**Source:** [wikipedia.org](http://en.wikipedia.org/wiki/Structural_pattern) 8 | -------------------------------------------------------------------------------- /source/structural/protection_proxy.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | ☔ Protection Proxy 3 | ------------------ 4 | 5 | The proxy pattern is used to provide a surrogate or placeholder object, which references an underlying object. 6 | Protection proxy is restricting access. 7 | 8 | ### Example 9 | */ 10 | protocol DoorOpening { 11 | func open(doors: String) -> String 12 | } 13 | 14 | final class HAL9000: DoorOpening { 15 | func open(doors: String) -> String { 16 | return ("HAL9000: Affirmative, Dave. I read you. Opened \(doors).") 17 | } 18 | } 19 | 20 | final class CurrentComputer: DoorOpening { 21 | private var computer: HAL9000! 22 | 23 | func authenticate(password: String) -> Bool { 24 | 25 | guard password == "pass" else { 26 | return false 27 | } 28 | 29 | computer = HAL9000() 30 | 31 | return true 32 | } 33 | 34 | func open(doors: String) -> String { 35 | 36 | guard computer != nil else { 37 | return "Access Denied. I'm afraid I can't do that." 38 | } 39 | 40 | return computer.open(doors: doors) 41 | } 42 | } 43 | /*: 44 | ### Usage 45 | */ 46 | let computer = CurrentComputer() 47 | let podBay = "Pod Bay Doors" 48 | 49 | computer.open(doors: podBay) 50 | 51 | computer.authenticate(password: "pass") 52 | computer.open(doors: podBay) 53 | -------------------------------------------------------------------------------- /source/structural/virtual_proxy.swift: -------------------------------------------------------------------------------- 1 | /*: 2 | 🍬 Virtual Proxy 3 | ---------------- 4 | 5 | The proxy pattern is used to provide a surrogate or placeholder object, which references an underlying object. 6 | Virtual proxy is used for loading object on demand. 7 | 8 | ### Example 9 | */ 10 | protocol HEVSuitMedicalAid { 11 | func administerMorphine() -> String 12 | } 13 | 14 | final class HEVSuit: HEVSuitMedicalAid { 15 | func administerMorphine() -> String { 16 | return "Morphine administered." 17 | } 18 | } 19 | 20 | final class HEVSuitHumanInterface: HEVSuitMedicalAid { 21 | 22 | lazy private var physicalSuit: HEVSuit = HEVSuit() 23 | 24 | func administerMorphine() -> String { 25 | return physicalSuit.administerMorphine() 26 | } 27 | } 28 | /*: 29 | ### Usage 30 | */ 31 | let humanInterface = HEVSuitHumanInterface() 32 | humanInterface.administerMorphine() 33 | --------------------------------------------------------------------------------