├── README.md
├── example
    ├── indexWithoutDI.php
    └── index.php
└── src
    └── DI.php


/README.md:
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1 | PHP Dependency Injection
2 | ========================
3 | Read more about that here:
4 | http://krasimirtsonev.com/blog/article/Dependency-Injection-in-PHP-example-how-to-DI-create-your-own-dependency-injection-container


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/example/indexWithoutDI.php:
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 1 | <?php
 2 | 
 3 |     class View {
 4 |         public function show($str) {
 5 |             echo "<p>".$str."</p>";
 6 |         }
 7 |     }
 8 |     
 9 |     class UsersModel {
10 |         public function get() {
11 |             return array(
12 |                 (object) array("firstName" => "John", "lastName" => "Doe"),
13 |                 (object) array("firstName" => "Mark", "lastName" => "Black")
14 |             );
15 |         }
16 |     }
17 |     
18 |     class Navigation {
19 |         private $view;
20 |         public function __construct() {
21 |             $this->view = new View();
22 |         }
23 |         public function show() {
24 |             $this->view->show('
25 |                 <a href="#" title="Home">Home</a> | 
26 |                 <a href="#" title="Home">Products</a> | 
27 |                 <a href="#" title="Home">Contacts</a>
28 |             ');
29 |         }
30 |     }
31 |     
32 |     class Content {
33 |     
34 |         private $title;
35 |         private $view;
36 |         private $usersModel;
37 |         
38 |         public function __construct($title) {
39 |             $this->title = $title;
40 |             $this->view = new View();
41 |             $this->usersModel = new UsersModel();
42 |         }
43 |         public function show() {  
44 |             $users = $this->usersModel->get();
45 |             $this->view->show($this->title);
46 |             foreach($users as $user) {
47 |                 $this->view->show($user->firstName." ".$user->lastName);
48 |             }
49 |         }
50 |     }
51 |     
52 |     class PageController {
53 |         public function show() {
54 |             $navigation = new Navigation();
55 |             $content = new Content("Content title!");
56 |             $navigation->show();
57 |             $content->show();
58 |         }
59 |     }
60 |     
61 |     $page = new PageController();
62 |     $page->show();
63 | 
64 | 
65 | ?>


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/example/index.php:
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 1 | <?php
 2 | 
 3 |     require_once("../src/DI.php");
 4 |     
 5 |     class View {
 6 |         public function show($str) {
 7 |             echo "<p>".$str."</p>";
 8 |         }
 9 |     }
10 |     
11 |     class UsersModel {
12 |         public function get() {
13 |             return array(
14 |                 (object) array("firstName" => "John", "lastName" => "Doe"),
15 |                 (object) array("firstName" => "Mark", "lastName" => "Black")
16 |             );
17 |         }
18 |     }
19 |     
20 |     /**
21 |     * @Inject view
22 |     */
23 |     class Navigation {
24 |         public function show() {
25 |             $this->view->show('
26 |                 <a href="#" title="Home">Home</a> | 
27 |                 <a href="#" title="Home">Products</a> | 
28 |                 <a href="#" title="Home">Contacts</a>
29 |             ');
30 |         }
31 |     }
32 |     
33 |     /**
34 |     * @Inject usersModel
35 |     * @Inject view
36 |     */
37 |     class Content {
38 |         private $title;
39 |         public function __construct($title) {
40 |             $this->title = $title;
41 |         }
42 |         public function show() {  
43 |             $this->users = $this->usersModel->get();
44 |             $this->view->show($this->title);
45 |             foreach($this->users as $user) {
46 |                 $this->view->show($user->firstName." ".$user->lastName);
47 |             }
48 |         }
49 |     }
50 |     
51 |     /**
52 |     * @Inject navigation
53 |     * @Inject content
54 |     */
55 |     class PageController {
56 |         public function show() {
57 |             $this->navigation->show();
58 |             $this->content->show();
59 |         }
60 |     }
61 |     
62 |     // mapping
63 |     DI::mapClass("navigation", "Navigation");
64 |     DI::mapClass("content", "Content", array("Content title!"));
65 |     DI::mapClass("view", "View");
66 |     DI::mapClassAsSingleton("usersModel", "UsersModel");
67 |     
68 |     // showing content
69 |     $page = DI::getInstanceOf("PageController");
70 |     $page->show();
71 |     
72 | 
73 | ?>


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/src/DI.php:
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 1 | <?php
 2 | 
 3 |     class DI {
 4 |     
 5 |         private static $map;
 6 |     
 7 |         public static function getInstanceOf($className, $arguments = null) {
 8 |         
 9 |             // checking if the class exists
10 |             if(!class_exists($className)) {
11 |                 throw new Exception("DI: missing class '".$className."'.");
12 |             }
13 |             
14 |             // initialized the ReflectionClass
15 |             $reflection = new ReflectionClass($className);
16 |             
17 |             // creating an instance of the class
18 |             if($arguments === null || count($arguments) == 0) {
19 |                $obj = new $className;
20 |             } else {
21 |                 if(!is_array($arguments)) {
22 |                     $arguments = array($arguments);
23 |                 }
24 |                $obj = $reflection->newInstanceArgs($arguments);
25 |             }
26 |             
27 |             // injecting
28 |             if($doc = $reflection->getDocComment()) {
29 |                 $lines = explode("\n", $doc);
30 |                 foreach($lines as $line) {
31 |                     if(count($parts = explode("@Inject", $line)) > 1) {
32 |                         $parts = explode(" ", $parts[1]);
33 |                         if(count($parts) > 1) {
34 |                             $key = $parts[1];
35 |                             $key = str_replace("\n", "", $key);
36 |                             $key = str_replace("\r", "", $key);
37 |                             if(isset(self::$map->$key)) {
38 |                                 switch(self::$map->$key->type) {
39 |                                     case "value":
40 |                                         $obj->$key = self::$map->$key->value;
41 |                                     break;
42 |                                     case "class":
43 |                                         $obj->$key = self::getInstanceOf(self::$map->$key->value, self::$map->$key->arguments);
44 |                                     break;
45 |                                     case "classSingleton":
46 |                                         if(self::$map->$key->instance === null) {
47 |                                             $obj->$key = self::$map->$key->instance = self::getInstanceOf(self::$map->$key->value, self::$map->$key->arguments);
48 |                                         } else {
49 |                                             $obj->$key = self::$map->$key->instance;
50 |                                         }
51 |                                     break;
52 |                                 }
53 |                             }
54 |                         }
55 |                     }
56 |                 }
57 |             }
58 |             
59 |             // return the created instance
60 |             return $obj;
61 |             
62 |         }
63 |         public static function mapValue($key, $value) {
64 |             self::addToMap($key, (object) array(
65 |                 "value" => $value,
66 |                 "type" => "value"
67 |             ));
68 |         }
69 |         public static function mapClass($key, $value, $arguments = null) {
70 |             self::addToMap($key, (object) array(
71 |                 "value" => $value,
72 |                 "type" => "class",
73 |                 "arguments" => $arguments
74 |             ));
75 |         }
76 |         public static function mapClassAsSingleton($key, $value, $arguments = null) {
77 |             self::addToMap($key, (object) array(
78 |                 "value" => $value,
79 |                 "type" => "classSingleton",
80 |                 "instance" => null,
81 |                 "arguments" => $arguments
82 |             ));
83 |         }
84 |         private static function addToMap($key, $obj) {
85 |             if(self::$map === null) {
86 |                 self::$map = (object) array();
87 |             }
88 |             self::$map->$key = $obj;
89 |         }
90 |     
91 |     }
92 | 
93 | ?>


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