├── assets ├── waves.gif ├── modal-on.gif ├── twitter.gif ├── mobilep2r.gif ├── modal-off.gif ├── async-await.png ├── chatbox-fixed.gif ├── drawer-glow.gif ├── drawer-noglow.gif ├── drawer-scroll.gif ├── chatbox-chaining.gif ├── chatbox-double-refresh.gif ├── chatbox-double-refresh-fix.gif ├── react-component-lifecycle-mounting.png ├── react-component-lifecycle-updating.png ├── when-do-i-know-im-ready-for-redux-1.gif ├── when-do-i-know-im-ready-for-redux-2.gif ├── when-do-i-know-im-ready-for-redux-3.gif ├── when-do-i-know-im-ready-for-redux-4.gif ├── react-component-lifecycle-unmounting.png └── i-wish-i-knew-these-before-diving-into-react.png ├── .editorconfig ├── README.md ├── .gitignore ├── articles ├── 2017-11-24-when-do-i-know-im-ready-for-redux.md ├── 2017-11-22-dynamic-import.md ├── 2017-11-01-javascript-async-await-explained.md ├── 2017-11-01-i-wish-i-knew-these-before-diving-into-react.md ├── 2017-12-07-await-vs-return-vs-return-await.md ├── 2017-11-15-overscroll-behavior.md 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-------------------------------------------------------------------------------- https://raw.githubusercontent.com/dev-reading/fe/HEAD/assets/i-wish-i-knew-these-before-diving-into-react.png -------------------------------------------------------------------------------- /.editorconfig: -------------------------------------------------------------------------------- 1 | # http://editorconfig.org 2 | root = true 3 | 4 | [*] 5 | charset = utf-8 6 | end_of_line = lf 7 | indent_size = 2 8 | indent_style = space 9 | insert_final_newline = true 10 | max_line_length = 80 11 | trim_trailing_whitespace = true 12 | 13 | [*.md] 14 | max_line_length = 0 15 | trim_trailing_whitespace = false 16 | 17 | [COMMIT_EDITMSG] 18 | max_line_length = 0 19 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # 前端热门文章阅读 2 | 3 | [dev-reading/fe](https://github.com/dev-reading/fe) 是一个阅读、导读、速读的 repo，不要依赖于 [dev-reading/fe](https://github.com/dev-reading/fe) 学习知识。本 repo 只是一个快速了解文章内容的工具，并不提供全文解读和翻译。你可以通过本平台快速了解文章里面的内容，找到感兴趣的文章，然后去阅读全文。 4 | 5 | 主播电台 ![](./assets/waves.gif) 6 | 7 | - [代码之声 - 网易云音乐](http://music.163.com/#/radio/?id=350628096&userid=71823138) 8 | - [喜马拉雅 FM](http://www.ximalaya.com/53565210/album/11353231) 9 | 10 | ## 目录 11 | 12 | - [我希望在深入 React 之前知道这些](./articles/2017-11-01-i-wish-i-knew-these-before-diving-into-react.md) 13 | - [10 分钟学会 JavaScript 的 Async/Await](./articles/2017-11-01-javascript-async-await-explained.md) 14 | - [软件 2.0](https://github.com/dev-reading/fe/issues/6) 15 | - [提升 React 函数组件 45% 的性能](https://github.com/dev-reading/fe/issues/7) 16 | 17 | [更多...](https://github.com/dev-reading/fe/issues) 18 | 19 | ## 交流 20 | 21 | - React技术交流1群(已满) 22 | - React技术交流2群 [450586076](https://jq.qq.com/?_wv=1027&k=5byxq2n) 23 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | # Logs 2 | logs 3 | *.log 4 | npm-debug.log* 5 | yarn-debug.log* 6 | yarn-error.log* 7 | 8 | # Runtime data 9 | pids 10 | *.pid 11 | *.seed 12 | *.pid.lock 13 | 14 | # Directory for instrumented libs generated by jscoverage/JSCover 15 | lib-cov 16 | 17 | # Coverage directory used by tools like istanbul 18 | coverage 19 | 20 | # nyc test coverage 21 | .nyc_output 22 | 23 | # Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files) 24 | .grunt 25 | 26 | # Bower dependency directory (https://bower.io/) 27 | bower_components 28 | 29 | # node-waf configuration 30 | .lock-wscript 31 | 32 | # Compiled binary addons (http://nodejs.org/api/addons.html) 33 | build/Release 34 | 35 | # Dependency directories 36 | node_modules/ 37 | jspm_packages/ 38 | 39 | # Typescript v1 declaration files 40 | typings/ 41 | 42 | # Optional npm cache directory 43 | .npm 44 | 45 | # Optional eslint cache 46 | .eslintcache 47 | 48 | # Optional REPL history 49 | .node_repl_history 50 | 51 | # Output of 'npm pack' 52 | *.tgz 53 | 54 | # Yarn Integrity file 55 | .yarn-integrity 56 | 57 | # dotenv environment variables file 58 | .env 59 | 60 | -------------------------------------------------------------------------------- /articles/2017-11-24-when-do-i-know-im-ready-for-redux.md: -------------------------------------------------------------------------------- 1 | # 4 张动图解释为什么（什么时候）使用 Redux 2 | 3 | > 过早优化是万恶之源 —— Donald Knuth 4 | 5 | 本文描述了**什么时候**开始使用 Redux。作者描述了在构建一个真实 React APP 时，从没有使用 Redux 到使用 Redux 的过程以及收获。 6 | 7 | 首先，**并不是所有的 React 应用程序都需要使用 Redux**。事实上，大多数非常简单的 React 应用程序根本不能从 Redux 中受益。 8 | 9 | ## 第 1 天 10 | 11 | 使用 React 本地组件状态 12 | 13 | React 使用[单向数据流](https://reactjs.org/docs/state-and-lifecycle.html#the-data-flows-down)，这意味着父组件把自身的状态作为属性传递给子组件。 14 | 15 | ![](../assets/when-do-i-know-im-ready-for-redux-1.gif) 16 | 17 | ## 第 5 天 18 | 19 | 随着添加更多的功能，**非父子**组件之间需要**共享**一些状态。 20 | 21 | 我们通过[提升状态](https://reactjs.org/docs/lifting-state-up.html)来解决这个问题。 22 | 23 | 这意味着我们将状态（和改变这个状态的函数）**提升到最接近的祖先**（Container Component）。我们将这些函数绑定到容器组件，并将它们作为属性向下传递。这意味着子组件可以触发其父组件中的状态更改，这将**更新树中的所有其他组件**。 24 | 25 | ![](../assets/when-do-i-know-im-ready-for-redux-2.gif) 26 | 27 | ## 第 20 天 28 | 29 | 随着添加了更多的功能和组件，我们的应用程序状态流程开始看起来像这样... 30 | 31 | ![](../assets/when-do-i-know-im-ready-for-redux-3.gif) 32 | 33 | ## 第 n 天 34 | 35 | 如果您开始遇到上述某些问题，则可能意味着您应该使用 Redux 了。 36 | 37 | ## Redux 38 | 39 | 当我们使用 Redux 后，状态变成了这样： 40 | 41 | ![](../assets/when-do-i-know-im-ready-for-redux-4.gif) 42 | 43 | 如果您的应用符合以下某些条件，那么我认为应该立即使用 Redux。 44 | 45 | - UI 可以根据应用程序状态显着变化 46 | - 并不总是以一种线性的，单向的方式流动 47 | - 许多不相关的组件以相同的方式更新状态 48 | - 状态树并不简单 49 | - 状态以许多不同的方式更新 50 | - 您需要能够撤消以前的用户操作 51 | 52 | ----------- 53 | 54 | > 阅读原文：[When do I know I’m ready for Redux?](https://medium.com/dailyjs/when-do-i-know-im-ready-for-redux-f34da253c85f) 55 | > 56 | > 讨论地址：[4 张动图解释为什么（什么时候）使用 Redux #11](https://github.com/dev-reading/fe/issues/11) 57 | > 58 | > 如果你想参与讨论，请[点击这里](https://github.com/dev-reading/fe) 59 | -------------------------------------------------------------------------------- /articles/2017-11-22-dynamic-import.md: -------------------------------------------------------------------------------- 1 | # 动态 import() | Dynamic import() 2 | 3 | - 浏览器支持：Chrome 63、 [Safari 24 预览版](https://webkit.org/blog/7423/release-notes-for-safari-technology-preview-24/) 4 | - TC39 proposal：https://github.com/tc39/proposal-dynamic-import 5 | - Stage：3 6 | - 规范：https://tc39.github.io/proposal-dynamic-import/ 7 | 8 | ## Static import 9 | 10 | Chrome 61 开始支持 ES2015 的 [modules](https://jakearchibald.com/2017/es-modules-in-browsers/)。 11 | 12 | `import` 导入的模块必须是字符串字面量，不能是变量。因为 `import` 是在编译时（pre-runtime）确定的，这要早于运行时。如下代码将报错: 13 | 14 | ```javascirpt 15 | if (name === 'jjc') { 16 | import myName from './jjc'; 17 | } else { 18 | import myName from './other'; 19 | } 20 | ``` 21 | 22 | 下面代码也会报错： 23 | 24 | ```javascirpt 25 | const name = 'jjc'; 26 | import myName from name; 27 | ``` 28 | 29 | 静态导入可以在编译阶段对代码进行静态分析、构建、tree-shaking 等。 30 | 31 | ## Dynamic import() 32 | 33 | 动态导入可以让我们进行**按需导入**等特性。 34 | 35 | 语法： 36 | 37 | ```javascript 38 | import(moduleSpecifier) 39 | ``` 40 | 41 | `import()` 返回一个 Promise 42 | 43 | ```javascript 44 | 51 | ``` 52 | 53 | **注意**：`import()` 虽然看上去像一个函数调用，但其实 `import` 只是恰好使用了括号语法而已（类似于 `super()`）。 54 | 这意味着 `import` 并不是继承自 `Function.prototype`，所以不能使用 `call` 和 `apply`。 55 | 使用 `const importAlias = import` 也是不行的。甚至，`import` 根本就不是一个对象！ 56 | 57 | ## 建议 58 | 59 | "静态 import" 和"动态 import()" 都同样重要。使用静态导入可以在运行之前构建模块的依赖关系，而动态导入可以在运行时按需加载模块。 60 | 61 | ----------- 62 | 63 | > 阅读原文：[Dynamic import()](https://developers.google.com/web/updates/2017/11/dynamic-import) 64 | > 65 | > 讨论地址：[动态 import()](https://github.com/dev-reading/fe/issues/10) 66 | > 67 | > 如果你想参与讨论，请[点击这里](https://github.com/dev-reading/fe) 68 | -------------------------------------------------------------------------------- /articles/2017-11-01-javascript-async-await-explained.md: -------------------------------------------------------------------------------- 1 | 1 分钟读完 [JavaScript Async/Await Explained in 10 Minutes](https://tutorialzine.com/2017/07/javascript-async-await-explained) 2 | 3 | # 10 分钟学会 JavaScript 的 Async/Await 4 | 5 | ![10 分钟学会 JavaScript 的 Async/Await](../assets/async-await.png) 6 | 7 | 以前我们使用 callback。 8 | 9 | 后来我们使用 Promise。 10 | 11 | 现在我们使用 Async/Await。 12 | 13 | ## 1、什么是 Async/Await？ 14 | 15 | Async - 定义异步函数(`async function someName(){...}`) 16 | 17 | - 自动把函数转换为 Promise 18 | - 当调用异步函数时，函数返回值会被 resolve 处理 19 | - 异步函数内部可以使用 `await` 20 | 21 | Await - 暂停异步函数的执行 (`var result = await someAsyncCall();`) 22 | 23 | - 当使用在 Promise 前面时，`await` 等待 Promise 完成，并返回 Promise 的结果 24 | - `await` **只能**和 Promise 一起使用，**不能**和 callback 一起使用 25 | - `await` 只能用在 `async` 函数中 26 | 27 | ## 2、Async/Await 是否会取代 Promise 28 | 29 | 不会。 30 | 31 | - Async/Await 底层依然使用了 Promise。 32 | - 多个异步函数同时执行时，需要借助 `Promise.all` 33 | 34 | ```javascript 35 | async function getABC() { 36 | let A = await getValueA(); // getValueA 花费 2 秒 37 | let B = await getValueB(); // getValueA 花费 4 秒 38 | let C = await getValueC(); // getValueA 花费 3 秒 39 | 40 | return A*B*C; 41 | } 42 | ``` 43 | 44 | 每次遇到 `await` 关键字时，Promise 都会停下在，一直到运行结束，所以总共花费是 2+4+3 = 9 秒。**`await` 把异步变成了同步**。 45 | 46 | ```javascript 47 | async function getABC() { 48 | // Promise.all() 允许同时执行所有的异步函数 49 | let results = await Promise.all([ getValueA, getValueB, getValueC ]); 50 | 51 | return results.reduce((total, value) => total * value); 52 | } 53 | ``` 54 | 55 | 函数总耗时为 4 秒（`getValueB` 的耗时）。 56 | 57 | ## 3、Async/Await 的错误处理 58 | 59 | 在 Async/Await 语法中，我们可以使用 try/catch 进行错误处理。在 Promise 中的 `.catch()` 分支会进入 `catch` 语句。 60 | 61 | ----------- 62 | 63 | > 阅读原文：[JavaScript Async/Await Explained in 10 Minutes](https://tutorialzine.com/2017/07/javascript-async-await-explained) 64 | > 65 | > 讨论地址：[10 分钟学会 JavaScript 的 Async/Await](https://github.com/dev-reading/fe/issues/3) 66 | > 67 | > 如果你想参与讨论，请[点击这里](https://github.com/dev-reading/fe) 68 | -------------------------------------------------------------------------------- /articles/2017-11-01-i-wish-i-knew-these-before-diving-into-react.md: -------------------------------------------------------------------------------- 1 | 1 分钟读完 [I wish I knew these before diving into React](https://engineering.opsgenie.com/i-wish-i-knew-these-before-diving-into-react-301e0ee2e488) 2 | 3 | # 我希望在深入 React 之前知道这些 4 | 5 | ![给 React 初学者的 6 个忠告](../assets/i-wish-i-knew-these-before-diving-into-react.png) 6 | 7 | [Canberk Morelli](https://engineering.opsgenie.com/@morellic) 是 OpsGenie 的一名前端工程师，正在使用 React 构建公司内部项目。 8 | 通过这篇文章可以使初学者不要犯同样的错误。 9 | 10 | ## 1、每次调用 `setState` 都会引起组件的重新渲染 re-render 11 | 12 | 每次**state 改变**或者**传入新的 props** 都会调用 `shouldComponentUpdate`。 13 | 14 | `shouldComponentUpdate` 默认返回 `true`，开发者可以根据自己的逻辑决定是否返回 `false`。 15 | 16 | 注意： 17 | 18 | - 不正确的 `shouldComponentUpdate` 逻辑可能引发错误：应该渲染的时候没有渲染，或者不应该渲染的时候却渲染了 19 | 20 | - 在 `shouldComponentUpdate` 进行复杂的判断容易引发性能问题，可以通过 [React’s Performance Tools](https://reactjs.org/docs/perf.html) 来查找。 21 | 22 | ## 2、`setState` 对状态的改变是异步的 23 | 24 | 调用 `setState` 后，组件的 `state` 并**不会**立即改变。 25 | 26 | 一个经常犯的错误就是在 `setState` 后马上使用 `this.state`。 27 | 28 | `setState` 还有另一种用法：`setState(updater, [callback])`，通过传递一个函数 `updater`。 29 | 第 2 个参数是修改完状态后的回调，但是不推荐在这里写业务逻辑，一个比较不错的地方是写到 `componentDidUpdate` 函数里。 30 | 31 | ## 3、组件生命周期很重要 32 | 33 | 生命周期大概分为 3 类： 34 | 35 | **挂载**：组件被创建并插入到 DOM 36 | 37 | ![](../assets/react-component-lifecycle-mounting.png) 38 | 39 | **更新**：组件正在重新渲染，一般是由 props 或 state 的改变引起的 40 | 41 | ![](../assets/react-component-lifecycle-updating.png) 42 | 43 | **卸载**：组件从 DOM 上移除 44 | 45 | ![](../assets/react-component-lifecycle-unmounting.png) 46 | 47 | ## 4、`componentWillReceiveProps` 的使用 48 | 49 | 当**组件的 props 改变时需要更新 state** 时使用这个方法。 50 | 51 | 注意： 52 | 53 | - 即使 props 没有改变，也会调用 `componentWillReceiveProps`，因此需要在函数内部比较 `this.props` 和 `nextProps` 54 | 55 | - 在一个**已挂载**组件接收新 props 前，`componentWillReceiveProps` 被调用，因此在挂载阶段是**不会**调用 `componentWillReceiveProps` 的 56 | 57 | ## 5、使用 React Developer Tools 58 | 59 | React Developer Tools 可以更方便的调试 React 应用。 60 | 61 | ## 6、使用 Create React App 62 | 63 | 官方推出的 Create React App 让开发者已**零配置**的方式快速创建 React 应用。 64 | 65 | ----------- 66 | 67 | > 阅读原文：[I wish I knew these before diving into React](https://engineering.opsgenie.com/i-wish-i-knew-these-before-diving-into-react-301e0ee2e488) 68 | > 69 | > 讨论地址：[我希望在深入 React 之前知道这些](https://github.com/dev-reading/fe/issues/2) 70 | > 71 | > 如果你想参与讨论，请[点击这里](https://github.com/dev-reading/fe) 72 | -------------------------------------------------------------------------------- /articles/2017-12-07-await-vs-return-vs-return-await.md: -------------------------------------------------------------------------------- 1 | # await、return 和 return await 的陷阱 2 | 3 | [await vs return vs return await](https://jakearchibald.com/2017/await-vs-return-vs-return-await/) 4 | 5 | 阅读时间大概 2 分钟 6 | 7 | ------------- 8 | 9 | `await`、`return` 和 `return await` 有很多容易被忽视的不同之处。 10 | 11 | 首先定义一个异步函数： 12 | 13 | ```javascript 14 | async function waitAndMaybeReject() { 15 | // 等待1秒 16 | await new Promise(r => setTimeout(r, 1000)); 17 | 18 | const isHeads = Boolean(Math.round(Math.random())); 19 | 20 | if (isHeads) { 21 | return 'yay'; 22 | } else { 23 | throw Error('Boo!'); 24 | } 25 | } 26 | ``` 27 | 28 | 函数等待 1 秒钟，然后有一半的概率返回 `"yay"`，一半的概率抛出异常。 29 | 30 | 31 | ## 1 直接调用 Just calling 32 | 33 | ```javascript 34 | async function foo() { 35 | try { 36 | waitAndMaybeReject(); 37 | } 38 | catch (e) { 39 | return 'caught'; 40 | } 41 | } 42 | ``` 43 | 44 | 直接调用 `foo`，函数总是返回 Promise **fulfill with undefined, without waiting**。 45 | 46 | ![](https://user-images.githubusercontent.com/359395/33812969-e650b798-de5b-11e7-82d5-e1551d332045.png) 47 | 48 | 永远不会返回 `"yay"`。 49 | 50 | ## 2 Awaiting 51 | 52 | ```javascript 53 | async function foo() { 54 | try { 55 | await waitAndMaybeReject(); 56 | } 57 | catch (e) { 58 | return 'caught'; 59 | } 60 | } 61 | ``` 62 | 63 | 调用 `foo`，函数返回的 Promise **等待 1 秒**，然后 **fulfill with `undefined`, or fulfill with `"caught"`**。 64 | 65 | 因为我们 await `waitAndMaybeReject()` 的结果，如果 rejected，我们的 catch 块捕获了异常，然后 `"caught"`，如果 fulfilled，我们的函数并没有返回 Promise 的值。 66 | 67 | ## 3 Returning 68 | 69 | ```javascript 70 | async function foo() { 71 | try { 72 | return waitAndMaybeReject(); 73 | } 74 | catch (e) { 75 | return 'caught'; 76 | } 77 | } 78 | ``` 79 | 80 | 调用 `foo`，函数返回的 Promise **等待 1 秒**，然后 **fulfill with `"yay"`, or reject with `Error('Boo!')`**。 81 | 82 | ## 4 Return-awaiting 83 | 84 | ```javascript 85 | async function foo() { 86 | try { 87 | return await waitAndMaybeReject(); 88 | } 89 | catch (e) { 90 | return 'caught'; 91 | } 92 | } 93 | ``` 94 | 95 | 调用 `foo`，函数返回的 Promise **等待 1 秒**，然后 **fulfill with `"yay"`, or fulfill with `"caught"`**。 96 | 97 | 这个是最符合我们预期的写法。 98 | 99 | 我们可以把它拆分一下： 100 | 101 | ```javascript 102 | async function foo() { 103 | try { 104 | // 等待 waitAndMaybeReject() 函数的结果 105 | // 把 fulfilled value 赋值给 fulfilledValue: 106 | const fulfilledValue = await waitAndMaybeReject(); 107 | // 如果 waitAndMaybeReject() 失败，抛出异常: 108 | return fulfilledValue; 109 | } 110 | catch (e) { 111 | return 'caught'; 112 | } 113 | } 114 | ``` 115 | 116 | ----------- 117 | 118 | > 阅读原文：[await vs return vs return await](https://jakearchibald.com/2017/await-vs-return-vs-return-await/) 119 | > 120 | > 讨论地址：[await、return 和 return await 的陷阱 #12](https://github.com/dev-reading/fe/issues/12) 121 | > 122 | > 如果你想参与讨论，请[点击这里](https://github.com/dev-reading/fe) 123 | -------------------------------------------------------------------------------- /articles/2017-11-15-overscroll-behavior.md: -------------------------------------------------------------------------------- 1 | # 使用 CSS overscroll-behavior 控制滚动行为：自定义下拉刷新和溢出效果 2 | 3 | CSS 的新属性 [overscroll-behavior](https://wicg.github.io/overscroll-behavior/) 允许开发者覆盖默认的浏览器**滚动**行为，一般用在滚动到顶部或者底部。 4 | 5 | ## 背景 6 | 7 | ### 滚动边界和滚动链接（boundary & chaining） 8 | 9 | 在 APP 中经常使用的抽屉导航(drawer)中，我们期望的效果是：滚动到底部时，滚动停止，因为我们到达了"滚动边界"。 10 | 11 | 但是在 Web 页面中滚动并不会停止，而是**继续滚动抽屉后面的内容**。效果如下： 12 | 13 | Drawer demo 14 | 15 | 我们称这种行为叫滚动链接（**scroll chaining**）。 16 | 17 | ### 下拉刷新 pull-to-refresh 18 | 19 | 下拉刷新是一个在移动端经常使用的操作，Chrome 移动版也增加了下拉刷新的支持。 20 | 21 | Twitter PWA 版本的自定义下拉刷新： 22 | 23 | 24 | 25 | Chrome Android 版的原生下拉刷新（刷新整个页面）： 26 | 27 | 28 | 29 | 很多时候我们需要**禁用原生的 pull-to-refresh 行为**。 30 | 31 | 以前我们想出各种方式来处理滚动，比如：不让页面滚动，而是使用 touch 事件处理滚动行为，使用 `100vw/vh` 设置页面高度禁止内容溢出或滚动，等等。。。 32 | 33 | 现在我们可以使用 `overscroll-behavior`。 34 | 35 | ## 介绍 overscroll-behavior 36 | 37 | `overscroll-behavior` 属性有 3 个值： 38 | 39 | 1. `auto` - 默认。元素的滚动会传播给祖先元素。 40 | 41 | 2. `contain` - 阻止滚动链接。滚动不会传播给祖先，但会显示元素内的原生效果。例如，Android 上的炫光效果或 iOS 上的回弹效果，当用户触摸滚动边界时会通知用户。注意：`overscroll-behavior: contain` 在 `html` 元素上使用**可防止滚动导航操作**。 42 | 43 | 3. `none` - 和 `contain` 一样，但它也可以防止节点本身的滚动效果（例如 Android 炫光或 iOS 回弹）。 44 | 45 | ## 阻止 fixed 定位元素的滚动传播 46 | 47 | 当一个 `fixed` 定位元素滚动到边界时，会滚动元素后面的内容。如下： 48 | 49 | Chatbox demo 50 | 51 | 我们可以使用 `overscroll-behavior: contain` 阻止这种行为。 52 | 53 | 如果我们有一个 `fixed` 定位的弹出层需要滚动时，默认是这样的，如下： 54 | 55 | 56 | 57 | 使用 `overscroll-behavior: contain` 可以阻止滚动传播给父元素，如下： 58 | 59 | 60 | 61 | ## 禁用下拉刷新 pull-to-refresh 62 | 63 | 禁用原生的下拉刷新效果，只需要在 `body` 或 `html` 元素添加： 64 | 65 | ```css 66 | body { 67 | /* Disables pull-to-refresh but allows overscroll glow effects. */ 68 | overscroll-behavior-y: contain; 69 | } 70 | ``` 71 | 72 | 当我们阻止了原生的下拉刷新后，就可以实现自己定义的下拉刷新。否则会出现两个下拉刷新： 73 | 74 | 之前： 75 | 76 | 77 | 78 | 之后： 79 | 80 | 81 | 82 | ## 禁用炫光和回弹效果 83 | 84 | 将属性制定为 `none`，可以禁用默认的滚动边界效果。 85 | 86 | ```css 87 | body { 88 | /* 禁用默认的下拉刷新和边界效果 89 | 但是依然可以进行滑动导航 */ 90 | overscroll-behavior-y: none; 91 | } 92 | ``` 93 | 94 | 之前: 95 | 96 | 97 | 98 | 之后： 99 | 100 | 101 | 102 | 如果想禁用左右滑动的手势导航，可以使用 `overscroll-behavior-x: none`。 103 | 104 | ## 完整的 demo 105 | 106 | Demo 地址：https://ebidel.github.io/demos/chatbox.html 107 | 108 | 源码：https://github.com/ebidel/demos/blob/master/chatbox.html 109 | 110 | 最终效果： 111 | 112 | Chatbox demo 113 | 114 | ----------- 115 | 116 | > 阅读原文：[Take control of your scroll: customizing pull-to-refresh and overflow effects](https://developers.google.com/web/updates/2017/11/overscroll-behavior) 117 | > 118 | > 讨论地址：[使用 CSS overscroll-behavior 控制滚动行为：自定义下拉刷新和溢出效果](https://github.com/dev-reading/fe/issues/9) 119 | > 120 | > 如果你想参与讨论，请[点击这里](https://github.com/dev-reading/fe) 121 | -------------------------------------------------------------------------------- /articles/2017-11-14-10-features-from-various-modern-languages-that-i-would-like-to-see-in-any-programming-language.md: -------------------------------------------------------------------------------- 1 | # 现代编程语言最有趣的 10 大特性 2 | 3 | [Ten interesting features from various modern languages](https://medium.com/@kasperpeulen/10-features-from-various-modern-languages-that-i-would-like-to-see-in-any-programming-language-f2a4a8ee6727) 4 | 5 | 阅读时间大概 2 分钟 6 | 7 | ------------- 8 | 9 | 如今大多数“现代”语言都依然使用老旧的 C-style 语法。 10 | 11 | 我们看一下编程语言的年代：Lisp (1958)、Smalltalk (1972)、Objective-C (1984)、Haskell (1990)、OCaml (1996)、等等。这些都是上个世纪的语言了。 12 | 13 | 本文作者选择了几个最新的语言：Reason、Swift、Kotlin、Dart 作为研究对象，总结了 10 个特性： 14 | 15 | ## 1 管道操作符 Pipeline operator 16 | 17 | Reason 语法 18 | 19 | ```reason 20 | let newScore = me.score 21 | |> double 22 | |> (it) => add(7, it) 23 | |> (it) => boundScore(0, 100, it); 24 | ``` 25 | 26 | 对应的 JavaScript 写法： 27 | 28 | ```javascript 29 | boundScore(0, 100, add(7, double(me.score))); 30 | ``` 31 | 32 | 而 es 也已经有了对应的提案：[tc39/proposal-pipeline-operator](https://github.com/tc39/proposal-pipeline-operator) 33 | 34 | ## 2 模式匹配 Pattern matching 35 | 36 | Kotlin 语法 37 | 38 | ```kotlin 39 | when (x) { 40 | in 1..10 -> print("x is in the range") 41 | in validNumbers -> print("x is valid") 42 | !in 10..20 -> print("x is outside the range") 43 | else -> print("none of the above") 44 | } 45 | ``` 46 | 47 | ## 3 Reactive (Rx) programming build in the language 48 | 49 | Dart 语法 50 | 51 | ```dart 52 | input.onKeyDown 53 | .where((e) => e.ctrlKey && e.code == 'Enter') 54 | .forEach((e) => dispatch(addTodoAction(e.target.value))); 55 | ``` 56 | 57 | ### 4 lambda 函数的默认参数 58 | 59 | Kotlin 语法（使用 `it` 作为默认参数） 60 | 61 | ```kotlin 62 | strings 63 | .filter{ it.length == 5 } 64 | .map{ it.toUpperCase() } 65 | ``` 66 | 67 | 对比 JavaScript 68 | 69 | ```js 70 | strings 71 | .filter{ it => it.length === 5 } 72 | .map{ it => it.toUpperCase() } 73 | ``` 74 | 75 | ## 5 解构 Destructuring 76 | 77 | Reason 语法： 78 | 79 | ```reason 80 | let someInts = (10, 20); 81 | let (ten, twenty) = someInts; 82 | 83 | type person = {name: string, age: int}; 84 | let somePerson = {name: "Guy", age: 30}; 85 | let {name, age} = somePerson; 86 | ``` 87 | 88 | Kotlin 语法 89 | 90 | ```kotlin 91 | data class Person(val name: String, val age: Int) 92 | val(name, age) = Person("Guy", 20) 93 | ``` 94 | 95 | es6 已经有了数组解构，es8 增加了对象解构 96 | 97 | ## 6 操作符级联 Cascade operator 98 | 99 | Dart 语法 100 | 101 | ```dart 102 | querySelector('#button') // Get an object. 103 | ..text = 'Confirm' // Use its members. 104 | ..classes.add('important') 105 | ..onClick.listen((e) => dispatch(confirmedAction())); 106 | ``` 107 | 108 | 对应的 JavaScript 写法 109 | 110 | ```js 111 | var button = querySelector('#button'); 112 | button.text = 'Confirm'; 113 | button.classed.add('important'); 114 | button.onClick.listen((e) => dispatch(confirmedAction())); 115 | ``` 116 | 117 | 如果使用 jQuery 基本在**写法上**就和 dart 一致了，但是两者有本质的不同 118 | 119 | ## 7 if 表达式 If expressions 120 | 121 | Kotlin 语法 122 | 123 | ```kotlin 124 | val result = if (param == 1) { 125 | "one" 126 | } else if (param == 2) { 127 | "two" 128 | } else { 129 | "three" 130 | } 131 | ``` 132 | 133 | 对于 if 表达式有人喜欢，有人讨厌，有人觉得无所谓；我是非常喜欢的，我之前在知乎有个回答：https://www.zhihu.com/question/55866176/answer/149009695 134 | 135 | ## 8 Try expressions 136 | 137 | Kotlin 语法 138 | 139 | ```kotlin 140 | val result = try { 141 | count() 142 | } catch (e: ArithmeticException) { 143 | throw IllegalStateException(e) 144 | } 145 | ``` 146 | ## 9 自动科里化 Automatic currying 147 | 148 | Reason 语法： 149 | 150 | ```reason 151 | let add = (x, y) => x + y; /* same as (x) => (y) => x + y; */ 152 | let five = add(2,3); /* 5 */ 153 | let alsoFive = add(2)(3); /* 5 */ 154 | let addFive = add(5); /* y => 5 + y; */ 155 | let eleven = addFive(6); /* 11 */ 156 | let twelve = addFive(7); /* 12 */ 157 | ``` 158 | 159 | ## 10 方法扩展 Method extensions 160 | 161 | Swift 语法： 162 | 163 | ```swift 164 | extension Int { 165 | func repetitions(task: () -> Void) { 166 | for _ in 0.. 阅读原文：[Ten interesting features from various modern languages](https://medium.com/@kasperpeulen/10-features-from-various-modern-languages-that-i-would-like-to-see-in-any-programming-language-f2a4a8ee6727) 187 | > 188 | > 讨论地址：[现代编程语言最有趣的 10 大特性](https://github.com/dev-reading/fe/issues/8) 189 | > 190 | > 如果你想参与讨论，请[点击这里](https://github.com/dev-reading/fe) 191 | -------------------------------------------------------------------------------- /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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You may not convey a covered 525 | work if you are a party to an arrangement with a third party that is 526 | in the business of distributing software, under which you make payment 527 | to the third party based on the extent of your activity of conveying 528 | the work, and under which the third party grants, to any of the 529 | parties who would receive the covered work from you, a discriminatory 530 | patent license (a) in connection with copies of the covered work 531 | conveyed by you (or copies made from those copies), or (b) primarily 532 | for and in connection with specific products or compilations that 533 | contain the covered work, unless you entered into that arrangement, 534 | or that patent license was granted, prior to 28 March 2007. 535 | 536 | Nothing in this License shall be construed as excluding or limiting 537 | any implied license or other defenses to infringement that may 538 | otherwise be available to you under applicable patent law. 539 | 540 | 12. No Surrender of Others' Freedom. 541 | 542 | If conditions are imposed on you (whether by court order, agreement or 543 | otherwise) that contradict the conditions of this License, they do not 544 | excuse you from the conditions of this License. If you cannot convey a 545 | covered work so as to satisfy simultaneously your obligations under this 546 | License and any other pertinent obligations, then as a consequence you may 547 | not convey it at all. For example, if you agree to terms that obligate you 548 | to collect a royalty for further conveying from those to whom you convey 549 | the Program, the only way you could satisfy both those terms and this 550 | License would be to refrain entirely from conveying the Program. 551 | 552 | 13. Use with the GNU Affero General Public License. 553 | 554 | Notwithstanding any other provision of this License, you have 555 | permission to link or combine any covered work with a work licensed 556 | under version 3 of the GNU Affero General Public License into a single 557 | combined work, and to convey the resulting work. The terms of this 558 | License will continue to apply to the part which is the covered work, 559 | but the special requirements of the GNU Affero General Public License, 560 | section 13, concerning interaction through a network will apply to the 561 | combination as such. 562 | 563 | 14. Revised Versions of this License. 564 | 565 | The Free Software Foundation may publish revised and/or new versions of 566 | the GNU General Public License from time to time. Such new versions will 567 | be similar in spirit to the present version, but may differ in detail to 568 | address new problems or concerns. 569 | 570 | Each version is given a distinguishing version number. If the 571 | Program specifies that a certain numbered version of the GNU General 572 | Public License "or any later version" applies to it, you have the 573 | option of following the terms and conditions either of that numbered 574 | version or of any later version published by the Free Software 575 | Foundation. If the Program does not specify a version number of the 576 | GNU General Public License, you may choose any version ever published 577 | by the Free Software Foundation. 578 | 579 | If the Program specifies that a proxy can decide which future 580 | versions of the GNU General Public License can be used, that proxy's 581 | public statement of acceptance of a version permanently authorizes you 582 | to choose that version for the Program. 583 | 584 | Later license versions may give you additional or different 585 | permissions. However, no additional obligations are imposed on any 586 | author or copyright holder as a result of your choosing to follow a 587 | later version. 588 | 589 | 15. Disclaimer of Warranty. 590 | 591 | THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY 592 | APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT 593 | HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY 594 | OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, 595 | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 596 | PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM 597 | IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF 598 | ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 599 | 600 | 16. Limitation of Liability. 601 | 602 | IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 603 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS 604 | THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY 605 | GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE 606 | USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF 607 | DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD 608 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), 609 | EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF 610 | SUCH DAMAGES. 611 | 612 | 17. Interpretation of Sections 15 and 16. 613 | 614 | If the disclaimer of warranty and limitation of liability provided 615 | above cannot be given local legal effect according to their terms, 616 | reviewing courts shall apply local law that most closely approximates 617 | an absolute waiver of all civil liability in connection with the 618 | Program, unless a warranty or assumption of liability accompanies a 619 | copy of the Program in return for a fee. 620 | 621 | END OF TERMS AND CONDITIONS 622 | 623 | How to Apply These Terms to Your New Programs 624 | 625 | If you develop a new program, and you want it to be of the greatest 626 | possible use to the public, the best way to achieve this is to make it 627 | free software which everyone can redistribute and change under these terms. 628 | 629 | To do so, attach the following notices to the program. It is safest 630 | to attach them to the start of each source file to most effectively 631 | state the exclusion of warranty; and each file should have at least 632 | the "copyright" line and a pointer to where the full notice is found. 633 | 634 | {one line to give the program's name and a brief idea of what it does.} 635 | Copyright (C) {year} {name of author} 636 | 637 | This program is free software: you can redistribute it and/or modify 638 | it under the terms of the GNU General Public License as published by 639 | the Free Software Foundation, either version 3 of the License, or 640 | (at your option) any later version. 641 | 642 | This program is distributed in the hope that it will be useful, 643 | but WITHOUT ANY WARRANTY; without even the implied warranty of 644 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 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 | . 675 | --------------------------------------------------------------------------------