Class yii\caching\ExpressionDependency

继承yii\caching\ExpressionDependency » yii\caching\Dependency » yii\base\BaseObject
实现yii\base\Configurable
可用自版本2.0
源代码 https://github.com/yiisoft/yii2/blob/master/framework/caching/ExpressionDependency.php

ExpressionDependency represents a dependency based on the result of a PHP expression.

ExpressionDependency will use eval() to evaluate the PHP expression. The dependency is reported as unchanged if and only if the result of the expression is the same as the one evaluated when storing the data to cache.

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.

For more details and usage information on Cache, see the guide article on caching.

公共属性

隐藏继承的属性

属性类型描述定义在
$data mixed The dependency data that is saved in cache and later is compared with the latest dependency data. yii\caching\Dependency
$expression string The string representation of a PHP expression whose result is used to determine the dependency. yii\caching\ExpressionDependency
$params mixed Custom parameters associated with this dependency. yii\caching\ExpressionDependency
$reusable boolean Whether this dependency is reusable or not. yii\caching\Dependency

公共方法

隐藏继承的方法

方法描述定义在
__call() 调用不是类方法的已命名方法. yii\base\BaseObject
__construct() 构造函数. yii\base\BaseObject
__get() 返回对象属性的值. yii\base\BaseObject
__isset() 检查属性是否已设置, 即已定义且不为null. yii\base\BaseObject
__set() 设置对象属性的值. yii\base\BaseObject
__unset() 将对象属性设置为null. yii\base\BaseObject
canGetProperty() 返回一个值, 指示属性是否可读. yii\base\BaseObject
canSetProperty() 返回一个值, 指示属性是否可写. yii\base\BaseObject
className() 返回此类的完全限定名称. yii\base\BaseObject
evaluateDependency() Evaluates the dependency by generating and saving the data related with dependency. yii\caching\Dependency
getHasChanged() Returns a value indicating whether the dependency has changed. yii\caching\Dependency
hasMethod() 返回一个值, 指示方法是否已定义. yii\base\BaseObject
hasProperty() 返回一个值, 指示属性是否已定义. yii\base\BaseObject
init() 初始化对象. yii\base\BaseObject
isChanged() Checks whether the dependency is changed. yii\caching\Dependency
resetReusableData() Resets all cached data for reusable dependencies. yii\caching\Dependency

受保护的方法

隐藏继承的方法

方法描述定义在
generateDependencyData() Generates the data needed to determine if dependency has been changed. yii\caching\ExpressionDependency
generateReusableHash() Generates a unique hash that can be used for retrieving reusable dependency data. yii\caching\Dependency

属性详情

$expression public 属性

The string representation of a PHP expression whose result is used to determine the dependency. A PHP expression can be any PHP code that evaluates to a value. To learn more about what an expression is, please refer to the php manual.

public string $expression 'true'
$params public 属性

Custom parameters associated with this dependency. You may get the value of this property in $expression using $this->params.

public mixed $params null

方法详情

generateDependencyData() protected 方法

Generates the data needed to determine if dependency has been changed.

This method returns the result of the PHP expression.

protected mixed generateDependencyData ( $cache )
$cache yii\caching\CacheInterface

The cache component that is currently evaluating this dependency

return mixed

The data needed to determine if dependency has been changed.