# Class yii\base\ActionFilter

Inheritance | yii\base\ActionFilter » yii\base\Behavior » yii\base\BaseObject
Implements | yii\base\Configurable
Subclasses | yii\filters\AccessControl, yii\filters\AjaxFilter, yii\filters\ContentNegotiator, yii\filters\Cors, yii\filters\HostControl, yii\filters\HttpCache, yii\filters\PageCache, yii\filters\RateLimiter, yii\filters\auth\AuthMethod, yii\filters\auth\CompositeAuth, yii\filters\auth\HttpBasicAuth, yii\filters\auth\HttpBearerAuth, yii\filters\auth\HttpHeaderAuth, yii\filters\auth\QueryParamAuth
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2/blob/master/framework/base/ActionFilter.php

ActionFilter is the base class for action filters.

An action filter will participate in the action execution workflow by responding to the `beforeAction` and `afterAction` events triggered by modules and controllers.

Check implementation of yii\filters\AccessControl, yii\filters\PageCache and yii\filters\HttpCache as examples on how to use it.

For more details and usage information on ActionFilter, see the guide article on filters.

## Public Properties

Hide inherited properties

Property | Type | Description | Defined By
--- | --- | --- | ---
$except | array | List of action IDs that this filter should not apply to. | yii\base\ActionFilter
$only | array | List of action IDs that this filter should apply to. | yii\base\ActionFilter
$owner | yii\base\Component|null | The owner of this behavior | yii\base\Behavior

## Public Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
__call() | Calls the named method which is not a class method. | yii\base\BaseObject
__construct() | Constructor. | 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
afterAction() | This method is invoked right after an action is executed. | yii\base\ActionFilter
afterFilter() |  | yii\base\ActionFilter
attach() | Attaches the behavior object to the component. | yii\base\ActionFilter
beforeAction() | This method is invoked right before an action is to be executed (after all possible filters.) You may override this method to do last-minute preparation for the action. | yii\base\ActionFilter
beforeFilter() |  | yii\base\ActionFilter
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() | Returns the fully qualified name of this class. | yii\base\BaseObject
detach() | Detaches the behavior object from the component. | yii\base\ActionFilter
events() | Declares event handlers for the $owner's events. | yii\base\Behavior
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

## Protected Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
getActionId() | Returns an action ID by converting yii\base\Action::$uniqueId into an ID relative to the module. | yii\base\ActionFilter
isActive() | Returns a value indicating whether the filter is active for the given action. | yii\base\ActionFilter

## Property Details

$except public property

List of action IDs that this filter should not apply to.

See also $only.

public array $except = []
$only public property

List of action IDs that this filter should apply to. If this property is not set, then the filter applies to all actions, unless they are listed in $except. If an action ID appears in both $only and $except, this filter will NOT apply to it.

Note that if the filter is attached to a module, the action IDs should also include child module IDs (if any) and controller IDs.

Since version 2.0.9 action IDs can be specified as wildcards, e.g. `site/*`.

See also $except.

public array $only = null

## Method Details

afterAction() public method

This method is invoked right after an action is executed.

You may override this method to do some postprocessing for the action.

public mixed afterAction ( $action, $result )
$action | yii\base\Action | The action just executed.
$result | mixed | The action execution result
return | mixed | The processed action result.

afterFilter() public method

public void afterFilter ( $event )
$event | yii\base\ActionEvent |

attach() public method

Attaches the behavior object to the component.

The default implementation will set the $owner property and attach event handlers as declared in events(). Make sure you call the parent implementation if you override this method.

public void attach ( $owner )
$owner | yii\base\Component | The component that this behavior is to be attached to.

beforeAction() public method

This method is invoked right before an action is to be executed (after all possible filters.) You may override this method to do last-minute preparation for the action.

public boolean beforeAction ( $action )
$action | yii\base\Action | The action to be executed.
return | boolean | Whether the action should continue to be executed.

beforeFilter() public method

public void beforeFilter ( $event )
$event | yii\base\ActionEvent |

detach() public method

Detaches the behavior object from the component.

The default implementation will unset the $owner property and detach event handlers declared in events(). Make sure you call the parent implementation if you override this method.

public void detach ( )

getActionId() protected method (available since version 2.0.7)

Returns an action ID by converting yii\base\Action::$uniqueId into an ID relative to the module.

protected string getActionId ( $action )
$action | yii\base\Action |

isActive() protected method

Returns a value indicating whether the filter is active for the given action.

protected boolean isActive ( $action )
$action | yii\base\Action | The action being filtered
return | boolean | Whether the filter is active for the given action.