AttributeBehavior

API reference › yii › behaviors › AttributeBehavior

class	`yii\behaviors\AttributeBehavior`
Extends	`yii\base\Behavior` » `yii\base\BaseObject`
Implements	`yii\base\Configurable`
Since	2.0
Source	`framework/behaviors/AttributeBehavior.php`

4 subclasses

AttributeBehavior automatically assigns a specified value to one or multiple attributes of an ActiveRecord object when certain events happen.

To use AttributeBehavior, configure the $attributes property which should specify the list of attributes that need to be updated and the corresponding events that should trigger the update. Then configure the $value property with a PHP callable whose return value will be used to assign to the current attribute(s). For example,

use yii\behaviors\AttributeBehavior;

public function behaviors()
{
    return [
        [
            'class' => AttributeBehavior::class,
            'attributes' => [
                ActiveRecord::EVENT_BEFORE_INSERT => 'attribute1',
                ActiveRecord::EVENT_BEFORE_UPDATE => 'attribute2',
            ],
            'value' => function ($event) {
                return 'some value';
            },
        ],
    ];
}

Because attribute values will be set automatically by this behavior, they are usually not user input and should therefore not be validated, i.e. they should not appear in the rules() method of the model.

Properties

Property	Type	Description	Defined by
`$attributes`	`array`	List of attributes that are to be automatically filled with the value specified via `$value`. Default: `[]`.	`AttributeBehavior`
`$owner`	`yii\base\T\|null`	The owner of this behavior Default: `null`.	`yii\base\Behavior`
`$preserveNonEmptyValues`	`bool`	Whether to preserve non-empty attribute values. Default: `false`. Available since 2.0.13.	`AttributeBehavior`
`$skipUpdateOnClean`	`bool`	Whether to skip this behavior when the `$owner` has not been modified Default: `true`. Available since 2.0.8.	`AttributeBehavior`
`$value`	`mixed`	The value that will be assigned to the current attributes. Default: `null`.	`AttributeBehavior`

Methods

Method	Description	Defined by
`__construct()`	Constructor.	`yii\base\BaseObject`
`__call()`	Calls the named method which is not a class method.	`yii\base\BaseObject`
`__get()`	Returns the value of an object property.	`yii\base\BaseObject`
`__isset()`	Checks if a property is set, i.e. defined and not null.	`yii\base\BaseObject`
`__set()`	Sets value of an object property.	`yii\base\BaseObject`
`__unset()`	Sets an object property to null.	`yii\base\BaseObject`
`attach()`	Attaches the behavior object to the component.	`yii\base\Behavior`
`canGetProperty()`	Returns a value indicating whether a property can be read.	`yii\base\BaseObject`
`canSetProperty()`	Returns a value indicating whether a property can be set.	`yii\base\BaseObject`
`className()` static	Returns the fully qualified name of this class.	`yii\base\BaseObject`
`detach()`	Detaches the behavior object from the component.	`yii\base\Behavior`
`evaluateAttributes()`	Evaluates the attribute value and assigns it to the current attributes.	`AttributeBehavior`
`events()`	Declares event handlers for the `$owner`’s events.	`AttributeBehavior`
`hasMethod()`	Returns a value indicating whether a method is defined.	`yii\base\BaseObject`
`hasProperty()`	Returns a value indicating whether a property is defined.	`yii\base\BaseObject`
`init()`	Initializes the object.	`yii\base\BaseObject`
`getValue()` protected	Returns the value for the current attributes.	`AttributeBehavior`

Property details

$attributes

public array $attributes = []

List of attributes that are to be automatically filled with the value specified via $value.

The array keys are the ActiveRecord events upon which the attributes are to be updated, and the array values are the corresponding attribute(s) to be updated. You can use a string to represent a single attribute, or an array to represent a list of attributes. For example,

[
    ActiveRecord::EVENT_BEFORE_INSERT => ['attribute1', 'attribute2'],
    ActiveRecord::EVENT_BEFORE_UPDATE => 'attribute2',
]

$value

public mixed $value = null

The value that will be assigned to the current attributes.

This can be an anonymous function, callable in array format (e.g. [$this, 'methodName']), an Expression object representing a DB expression (e.g. new Expression('NOW()')), scalar, string or an arbitrary value. If the former, the return value of the function will be assigned to the attributes. The signature of the function should be as follows,

function ($event)
{
    // return value will be assigned to the attribute
}

Method details

evaluateAttributes()

public function evaluateAttributes(yii\base\Event $event): mixed

Evaluates the attribute value and assigns it to the current attributes.

Parameters

Parameter	Type	Description
`$event`	`yii\base\Event`

Returns

mixed

events()

public function events(): array

Declares event handlers for the $owner’s events.

Child classes may override this method to declare what PHP callbacks should be attached to the events of the $owner component.

The callbacks will be attached to the $owner’s events when the behavior is attached to the owner; and they will be detached from the events when the behavior is detached from the component.

The callbacks can be any of the following:

method in this behavior: 'handleClick', equivalent to [$this, 'handleClick']
object method: [$object, 'handleClick']
static method: ['Page', 'handleClick']
anonymous function: function ($event) { ... }

The following is an example:

[
    Model::EVENT_BEFORE_VALIDATE => 'myBeforeValidate',
    Model::EVENT_AFTER_VALIDATE => 'myAfterValidate',
]

Returns

array: Events (array keys) and the corresponding event handler methods (array values).

getValue()

protected function getValue(yii\base\Event $event): mixed

Returns the value for the current attributes.

This method is called by evaluateAttributes(). Its return value will be assigned to the attributes corresponding to the triggering event.

Parameters

Parameter	Type	Description
`$event`	`yii\base\Event`	The event that triggers the current attribute updating.

Returns

mixed: The attribute value