|
1
|
|
|
<?php |
|
2
|
|
|
/** |
|
3
|
|
|
* @link http://www.yiiframework.com/ |
|
4
|
|
|
* @copyright Copyright (c) 2008 Yii Software LLC |
|
5
|
|
|
* @license http://www.yiiframework.com/license/ |
|
6
|
|
|
*/ |
|
7
|
|
|
|
|
8
|
|
|
namespace yii\base; |
|
9
|
|
|
|
|
10
|
|
|
use Yii; |
|
11
|
|
|
|
|
12
|
|
|
/** |
|
13
|
|
|
* Component is the base class that implements the *property*, *event* and *behavior* features. |
|
14
|
|
|
* |
|
15
|
|
|
* Component provides the *event* and *behavior* features, in addition to the *property* feature which is implemented in |
|
16
|
|
|
* its parent class [[\yii\base\Object|Object]]. |
|
17
|
|
|
* |
|
18
|
|
|
* Event is a way to "inject" custom code into existing code at certain places. For example, a comment object can trigger |
|
19
|
|
|
* an "add" event when the user adds a comment. We can write custom code and attach it to this event so that when the event |
|
20
|
|
|
* is triggered (i.e. comment will be added), our custom code will be executed. |
|
21
|
|
|
* |
|
22
|
|
|
* An event is identified by a name that should be unique within the class it is defined at. Event names are *case-sensitive*. |
|
23
|
|
|
* |
|
24
|
|
|
* One or multiple PHP callbacks, called *event handlers*, can be attached to an event. You can call [[trigger()]] to |
|
25
|
|
|
* raise an event. When an event is raised, the event handlers will be invoked automatically in the order they were |
|
26
|
|
|
* attached. |
|
27
|
|
|
* |
|
28
|
|
|
* To attach an event handler to an event, call [[on()]]: |
|
29
|
|
|
* |
|
30
|
|
|
* ```php |
|
31
|
|
|
* $post->on('update', function ($event) { |
|
32
|
|
|
* // send email notification |
|
33
|
|
|
* }); |
|
34
|
|
|
* ``` |
|
35
|
|
|
* |
|
36
|
|
|
* In the above, an anonymous function is attached to the "update" event of the post. You may attach |
|
37
|
|
|
* the following types of event handlers: |
|
38
|
|
|
* |
|
39
|
|
|
* - anonymous function: `function ($event) { ... }` |
|
40
|
|
|
* - object method: `[$object, 'handleAdd']` |
|
41
|
|
|
* - static class method: `['Page', 'handleAdd']` |
|
42
|
|
|
* - global function: `'handleAdd'` |
|
43
|
|
|
* |
|
44
|
|
|
* The signature of an event handler should be like the following: |
|
45
|
|
|
* |
|
46
|
|
|
* ```php |
|
47
|
|
|
* function foo($event) |
|
48
|
|
|
* ``` |
|
49
|
|
|
* |
|
50
|
|
|
* where `$event` is an [[Event]] object which includes parameters associated with the event. |
|
51
|
|
|
* |
|
52
|
|
|
* You can also attach a handler to an event when configuring a component with a configuration array. |
|
53
|
|
|
* The syntax is like the following: |
|
54
|
|
|
* |
|
55
|
|
|
* ```php |
|
56
|
|
|
* [ |
|
57
|
|
|
* 'on add' => function ($event) { ... } |
|
58
|
|
|
* ] |
|
59
|
|
|
* ``` |
|
60
|
|
|
* |
|
61
|
|
|
* where `on add` stands for attaching an event to the `add` event. |
|
62
|
|
|
* |
|
63
|
|
|
* Sometimes, you may want to associate extra data with an event handler when you attach it to an event |
|
64
|
|
|
* and then access it when the handler is invoked. You may do so by |
|
65
|
|
|
* |
|
66
|
|
|
* ```php |
|
67
|
|
|
* $post->on('update', function ($event) { |
|
68
|
|
|
* // the data can be accessed via $event->data |
|
69
|
|
|
* }, $data); |
|
70
|
|
|
* ``` |
|
71
|
|
|
* |
|
72
|
|
|
* A behavior is an instance of [[Behavior]] or its child class. A component can be attached with one or multiple |
|
73
|
|
|
* behaviors. When a behavior is attached to a component, its public properties and methods can be accessed via the |
|
74
|
|
|
* component directly, as if the component owns those properties and methods. |
|
75
|
|
|
* |
|
76
|
|
|
* To attach a behavior to a component, declare it in [[behaviors()]], or explicitly call [[attachBehavior]]. Behaviors |
|
77
|
|
|
* declared in [[behaviors()]] are automatically attached to the corresponding component. |
|
78
|
|
|
* |
|
79
|
|
|
* One can also attach a behavior to a component when configuring it with a configuration array. The syntax is like the |
|
80
|
|
|
* following: |
|
81
|
|
|
* |
|
82
|
|
|
* ```php |
|
83
|
|
|
* [ |
|
84
|
|
|
* 'as tree' => [ |
|
85
|
|
|
* 'class' => 'Tree', |
|
86
|
|
|
* ], |
|
87
|
|
|
* ] |
|
88
|
|
|
* ``` |
|
89
|
|
|
* |
|
90
|
|
|
* where `as tree` stands for attaching a behavior named `tree`, and the array will be passed to [[\Yii::createObject()]] |
|
91
|
|
|
* to create the behavior object. |
|
92
|
|
|
* |
|
93
|
|
|
* For more details and usage information on Component, see the [guide article on components](guide:concept-components). |
|
94
|
|
|
* |
|
95
|
|
|
* @property Behavior[] $behaviors List of behaviors attached to this component. This property is read-only. |
|
96
|
|
|
* |
|
97
|
|
|
* @author Qiang Xue <[email protected]> |
|
98
|
|
|
* @since 2.0 |
|
99
|
|
|
*/ |
|
100
|
|
|
class Component extends Object implements ComponentInterface |
|
101
|
|
|
{ |
|
102
|
|
|
use ComponentTrait; |
|
103
|
|
|
} |
|
104
|
|
|
|
yiisoft /
yii2
