CExpressionDependency

Package system.caching.dependencies
Inheritance class CExpressionDependency » CCacheDependency » CComponent
Implements ICacheDependency
Since 1.0
Source Code framework/caching/dependencies/CExpressionDependency.php
CExpressionDependency represents a dependency based on the result of a PHP expression.

CExpressionDependency performs dependency checking based on the result of a PHP expression. The dependency is reported as unchanged if and only if the result is the same as the one evaluated when storing the data to cache.

Public Properties

Property Type Description Defined By
dependentData mixed the data used to determine if dependency has been changed. CCacheDependency
expression string the PHP expression whose result is used to determine the dependency. CExpressionDependency
hasChanged boolean whether the dependency has changed. CCacheDependency
reuseDependentData boolean Whether this dependency is reusable or not. CCacheDependency

Public Methods

Method Description Defined By
__call() Calls the named method which is not a class method. CComponent
__construct() Constructor. CExpressionDependency
__get() Returns a property value, an event handler list or a behavior based on its name. CComponent
__isset() Checks if a property value is null. CComponent
__set() Sets value of a component property. CComponent
__unset() Sets a component property to be null. CComponent
asa() Returns the named behavior object. CComponent
attachBehavior() Attaches a behavior to this component. CComponent
attachBehaviors() Attaches a list of behaviors to the component. CComponent
attachEventHandler() Attaches an event handler to an event. CComponent
canGetProperty() Determines whether a property can be read. CComponent
canSetProperty() Determines whether a property can be set. CComponent
detachBehavior() Detaches a behavior from the component. CComponent
detachBehaviors() Detaches all behaviors from the component. CComponent
detachEventHandler() Detaches an existing event handler. CComponent
disableBehavior() Disables an attached behavior. CComponent
disableBehaviors() Disables all behaviors attached to this component. CComponent
enableBehavior() Enables an attached behavior. CComponent
enableBehaviors() Enables all behaviors attached to this component. CComponent
evaluateDependency() Evaluates the dependency by generating and saving the data related with dependency. CCacheDependency
evaluateExpression() Evaluates a PHP expression or callback under the context of this component. CComponent
getDependentData() Returns the data used to determine if dependency has been changed. This data is available after evaluateDependency is called. CCacheDependency
getEventHandlers() Returns the list of attached event handlers for an event. CComponent
getHasChanged() Returns whether the dependency has changed. CCacheDependency
hasEvent() Determines whether an event is defined. CComponent
hasEventHandler() Checks whether the named event has attached handlers. CComponent
hasProperty() Determines whether a property is defined. CComponent
raiseEvent() Raises an event. CComponent
resetReusableData() Resets cached data for reusable dependencies. CCacheDependency

Protected Methods

Method Description Defined By
generateDependentData() Generates the data needed to determine if dependency has been changed. CExpressionDependency

Property Details

expression property

public string $expression;

the PHP expression whose result is used to determine the dependency. The expression can also be a valid serializable PHP callback. It will be passed with a parameter which is the dependency object itself.

The PHP expression will be evaluated using evaluateExpression.

A PHP expression can be any PHP code that has a value. To learn more about what an expression is, please refer to the php manual.

Method Details

__construct() method

public void __construct(string $expression='true')
$expression string the PHP expression whose result is used to determine the dependency.
Source Code: framework/caching/dependencies/CExpressionDependency.php#41 (show)
public function __construct($expression='true')
{
    
$this->expression=$expression;
}

Constructor.

generateDependentData() method

protected mixed generateDependentData()
{return} mixed the data needed to determine if dependency has been changed.
Source Code: framework/caching/dependencies/CExpressionDependency.php#51 (show)
protected function generateDependentData()
{
    return 
$this->evaluateExpression($this->expression);
}

Generates the data needed to determine if dependency has been changed. This method returns the result of the PHP expression.

© 2008–2017 by Yii Software LLC
Licensed under the three clause BSD license.
http://www.yiiframework.com/doc/api/1.1/CExpressionDependency