TagDependency

API reference › yii › caching › TagDependency

class	`yii\caching\TagDependency`
Extends	`Dependency` » `yii\base\BaseObject`
Implements	`yii\base\Configurable`
Since	2.0
Source	`framework/caching/TagDependency.php`

TagDependency associates a cached data item with one or multiple $tags.

By calling invalidate(), you can invalidate all cached data items that are associated with the specified tag name(s).

// setting multiple cache keys to store data forever and tagging them with "user-123"
Yii::$app->cache->set('user_42_profile', '', 0, new TagDependency(['tags' => 'user-123']));
Yii::$app->cache->set('user_42_stats', '', 0, new TagDependency(['tags' => 'user-123']));

// invalidating all keys tagged with "user-123"
TagDependency::invalidate(Yii::$app->cache, 'user-123');

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

Properties

Property	Type	Description	Defined by
`$data`	`mixed`	The dependency data that is saved in cache and later is compared with the latest dependency data. Default: `null`.	`Dependency`
`$reusable`	`bool`	Whether this dependency is reusable or not. Default: `false`.	`Dependency`
`$tags`	`string\|array`	A list of tag names for this dependency. Default: `[]`.	`TagDependency`

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`
`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`
`evaluateDependency()`	Evaluates the dependency by generating and saving the data related with dependency.	`Dependency`
`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`
`invalidate()` static	Invalidates all of the cached data items that are associated with any of the specified `$tags`.	`TagDependency`
`isChanged()`	Checks whether the dependency is changed.	`TagDependency`
`resetReusableData()` static	Resets all cached data for reusable dependencies.	`Dependency`
`generateDependencyData()` protected	Generates the data needed to determine if dependency has been changed.	`TagDependency`
`generateReusableHash()` protected	Generates a unique hash that can be used for retrieving reusable dependency data.	`Dependency`
`getTimestamps()` protected	Returns the timestamps for the specified tags.	`TagDependency`
`touchKeys()` protected static	Generates the timestamp for the specified cache keys.	`TagDependency`

Property details

$tags

public string|array $tags = []

A list of tag names for this dependency.

For a single tag, you may specify it as a string.

Method details

invalidate()

public static function invalidate(yii\caching\CacheInterface $cache, string|array $tags): mixed

Invalidates all of the cached data items that are associated with any of the specified $tags.

Parameters

Parameter	Type	Description
`$cache`	`CacheInterface`	The cache component that caches the data items
`$tags`	`string\|array`

Returns

mixed

isChanged()

public function isChanged(mixed $cache): bool

Checks whether the dependency is changed.

Parameters

Parameter	Type	Description
`$cache`	`mixed`	The cache component that is currently evaluating this dependency

Returns

bool: Whether the dependency has changed.

Since

2.0.11

generateDependencyData()

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

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

This method does nothing in this class.

Parameters

Parameter	Type	Description
`$cache`	`CacheInterface`	The cache component that is currently evaluating this dependency

Returns

mixed: The data needed to determine if dependency has been changed.

getTimestamps()

protected function getTimestamps(yii\caching\CacheInterface $cache, string[] $tags): array

Returns the timestamps for the specified tags.

Parameters

Parameter	Type	Description
`$cache`	`CacheInterface`
`$tags`	`string[]`

Returns

array: The timestamps indexed by the specified tags.

touchKeys()

protected static function touchKeys(yii\caching\CacheInterface $cache, string[] $keys): array

Generates the timestamp for the specified cache keys.

Parameters

Parameter	Type	Description
`$cache`	`CacheInterface`
`$keys`	`string[]`

Returns

array: The timestamp indexed by cache keys