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Changed subsection order 

It really should be: defining, attaching, using.
tags/2.0.0-rc
Larry Ullman 10 years ago
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  1. 197
      docs/guide/concept-behaviors.md

197
docs/guide/concept-behaviors.md
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@ -9,50 +9,90 @@ can respond to the [events](concept-events.md) triggered by the component, which
code execution of the component.
Using Behaviors <a name="using-behaviors"></a>
---------------
Defining Behaviors <a name="defining-behaviors"></a>
------------------
To use a behavior, you first need to attach it to a [[yii\base\Component|component]]. We will describe how to
attach a behavior in the next subsection.
To define a behavior, create a class by extending from [[yii\base\Behavior]] or its child class. For example,
Once a behavior is attached to a component, its usage is straightforward.
```php
namespace app\components;
You can access a *public* member variable or a [property](concept-properties.md) defined by a getter and/or a setter
of the behavior through the component it is attached to, like the following,
use yii\base\Model;
use yii\base\Behavior;
```php
// "prop1" is a property defined in the behavior class
echo $component->prop1;
$component->prop1 = $value;
```
class MyBehavior extends Behavior
{
public $prop1;
You can also call a *public* method of the behavior similarly,
private $_prop2;
```php
// bar() is a public method defined in the behavior class
$component->bar();
public function getProp2()
{
return $this->_prop2;
}
public function setProp2($value)
{
$this->_prop2 = $value;
}
public function foo()
{
// ...
}
}
```
As you can see, although `$component` does not define `prop1` and `bar()`, they can be used as if they are part
of the component definition.
The above code defines the behavior class `app\components\MyBehavior` which will provide two properties
`prop1` and `prop2`, and one method `foo()` to the component it is attached to. Note that property `prop2`
is defined via the getter `getProp2()` and the setter `setProp2()`. This is so because [[yii\base\Object]]
is an ancestor class of [[yii\base\Behavior]], which supports defining [properties](concept-properties.md) by getters/setters.
If two behaviors define the same property or method and they are both attached to the same component,
the behavior that is attached to the component first will take precedence when the property or method is being accessed.
Within a behavior, you can access the component that the behavior is attached to through the [[yii\base\Behavior::owner]] property.
A behavior may be associated with a name when it is attached to a component. If this is the case, you may
access the behavior object using the name, like the following,
If a behavior needs to respond to the events triggered by the component it is attached to, it should override the
[[yii\base\Behavior::events()]] method. For example,
```php
$behavior = $component->getBehavior('myBehavior');
namespace app\components;
use yii\db\ActiveRecord;
use yii\base\Behavior;
class MyBehavior extends Behavior
{
// ...
public function events()
{
return [
ActiveRecord::EVENT_BEFORE_VALIDATE => 'beforeValidate',
];
}
public function beforeValidate($event)
{
// ...
}
}
```
You may also get all behaviors attached to a component:
The [[yii\base\Behavior::events()|events()]] method should return a list of events and their corresponding handlers.
The above example declares that the [[yii\db\ActiveRecord::EVENT_BEFORE_VALIDATE|EVENT_BEFORE_VALIDATE]] event and
its handler `beforeValidate()`. When specifying an event handler, you may use one of the following formats:
* a string that refers to the name of a method of the behavior class, like the example above;
* an array of an object or class name, and a method name, e.g., `[$object, 'methodName']`;
* an anonymous function.
The signature of an event handler should be as follows, where `$event` refers to the event parameter. Please refer
to the [Events](concept-events.md) section for more details about events.
```php
$behaviors = $component->getBehaviors();
function ($event) {
}
```
Attaching Behaviors <a name="attaching-behaviors"></a>
-------------------
@ -150,108 +190,69 @@ please refer to the [Configurations](concept-configurations.md#configuration-for
]
```
Using Behaviors <a name="using-behaviors"></a>
---------------
Detaching Behaviors <a name="detaching-behaviors"></a>
-------------------
To use a behavior, you first need to attach it to a [[yii\base\Component|component]]. We will describe how to
attach a behavior in the next subsection.
To detach a behavior, you can call [[yii\base\Component::detachBehavior()]] with the name associated with the behavior:
Once a behavior is attached to a component, its usage is straightforward.
You can access a *public* member variable or a [property](concept-properties.md) defined by a getter and/or a setter
of the behavior through the component it is attached to, like the following,
```php
$component->detachBehavior('myBehavior1');
// "prop1" is a property defined in the behavior class
echo $component->prop1;
$component->prop1 = $value;
```
You may also detach *all* behaviors:
You can also call a *public* method of the behavior similarly,
```php
$component->detachBehaviors();
// bar() is a public method defined in the behavior class
$component->bar();
```
As you can see, although `$component` does not define `prop1` and `bar()`, they can be used as if they are part
of the component definition.
Defining Behaviors <a name="defining-behaviors"></a>
------------------
If two behaviors define the same property or method and they are both attached to the same component,
the behavior that is attached to the component first will take precedence when the property or method is being accessed.
To define a behavior, create a class by extending from [[yii\base\Behavior]] or its child class. For example,
A behavior may be associated with a name when it is attached to a component. If this is the case, you may
access the behavior object using the name, like the following,
```php
namespace app\components;
use yii\base\Model;
use yii\base\Behavior;
class MyBehavior extends Behavior
{
public $prop1;
private $_prop2;
public function getProp2()
{
return $this->_prop2;
}
public function setProp2($value)
{
$this->_prop2 = $value;
}
public function foo()
{
// ...
}
}
$behavior = $component->getBehavior('myBehavior');
```
The above code defines the behavior class `app\components\MyBehavior` which will provide two properties
`prop1` and `prop2`, and one method `foo()` to the component it is attached to. Note that property `prop2`
is defined via the getter `getProp2()` and the setter `setProp2()`. This is so because [[yii\base\Object]]
is an ancestor class of [[yii\base\Behavior]], which supports defining [properties](concept-properties.md) by getters/setters.
Within a behavior, you can access the component that the behavior is attached to through the [[yii\base\Behavior::owner]] property.
If a behavior needs to respond to the events triggered by the component it is attached to, it should override the
[[yii\base\Behavior::events()]] method. For example,
You may also get all behaviors attached to a component:
```php
namespace app\components;
$behaviors = $component->getBehaviors();
```
use yii\db\ActiveRecord;
use yii\base\Behavior;
class MyBehavior extends Behavior
{
// ...
public function events()
{
return [
ActiveRecord::EVENT_BEFORE_VALIDATE => 'beforeValidate',
];
}
public function beforeValidate($event)
{
// ...
}
}
```
Detaching Behaviors <a name="detaching-behaviors"></a>
-------------------
The [[yii\base\Behavior::events()|events()]] method should return a list of events and their corresponding handlers.
The above example declares that the [[yii\db\ActiveRecord::EVENT_BEFORE_VALIDATE|EVENT_BEFORE_VALIDATE]] event and
its handler `beforeValidate()`. When specifying an event handler, you may use one of the following formats:
To detach a behavior, you can call [[yii\base\Component::detachBehavior()]] with the name associated with the behavior:
* a string that refers to the name of a method of the behavior class, like the example above;
* an array of an object or class name, and a method name, e.g., `[$object, 'methodName']`;
* an anonymous function.
```php
$component->detachBehavior('myBehavior1');
```
The signature of an event handler should be as follows, where `$event` refers to the event parameter. Please refer
to the [Events](concept-events.md) section for more details about events.
You may also detach *all* behaviors:
```php
function ($event) {
}
$component->detachBehaviors();
```
Using `TimestampBehavior` <a name="using-timestamp-behavior"></a>
-------------------------

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