function Cache::mergeTags

Same name in other branches
  1. 9 core/lib/Drupal/Core/Cache/Cache.php \Drupal\Core\Cache\Cache::mergeTags()
  2. 10 core/lib/Drupal/Core/Cache/Cache.php \Drupal\Core\Cache\Cache::mergeTags()
  3. 11.x core/lib/Drupal/Core/Cache/Cache.php \Drupal\Core\Cache\Cache::mergeTags()

Merges arrays of cache tags and removes duplicates.

The cache tags array is returned in a format that is valid for \Drupal\Core\Cache\CacheBackendInterface::set().

When caching elements, it is necessary to collect all cache tags into a single array, from both the element itself and all child elements. This allows items to be invalidated based on all tags attached to the content they're constituted from.

Parameters

array $a: Cache tags array to merge.

array $b: Cache tags array to merge.

Return value

string[] The merged array of cache tags.

72 calls to Cache::mergeTags()
AggregatorFeedBlock::getCacheTags in core/modules/aggregator/src/Plugin/Block/AggregatorFeedBlock.php
ArgumentPluginBase::getCacheTags in core/modules/views/src/Plugin/views/argument/ArgumentPluginBase.php
The cache tags associated with this object.
AssertPageCacheContextsAndTagsTrait::assertCacheTags in core/modules/system/src/Tests/Cache/AssertPageCacheContextsAndTagsTrait.php
Ensures that some cache tags are present in the current response.
AssertPageCacheContextsAndTagsTrait::assertCacheTags in core/modules/system/tests/src/Functional/Cache/AssertPageCacheContextsAndTagsTrait.php
Ensures that some cache tags are present in the current response.
BlockContentCacheTagsTest::testBlock in core/modules/block_content/tests/src/Functional/BlockContentCacheTagsTest.php
Tests that the block is cached with the correct contexts and tags.

... See full list

File

core/lib/Drupal/Core/Cache/Cache.php, line 57

Class

Cache
Helper methods for cache.

Namespace

Drupal\Core\Cache

Code

public static function mergeTags(array $a = [], array $b = []) {
    assert(Inspector::assertAllStrings($a) && Inspector::assertAllStrings($b), 'Cache tags must be valid strings');
    $cache_tags = array_unique(array_merge($a, $b));
    sort($cache_tags);
    return $cache_tags;
}

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