public static function Cache::keyFromQuery in Drupal 8

Same name and namespace in other branches

1. 9 core/lib/Drupal/Core/Cache/Cache.php \Drupal\Core\Cache\Cache::keyFromQuery()
2. 10 core/lib/Drupal/Core/Cache/Cache.php \Drupal\Core\Cache\Cache::keyFromQuery()

Generates a hash from a query object, to be used as part of the cache key.

This smart caching strategy saves Drupal from querying and rendering to HTML when the underlying query is unchanged.

Expensive queries should use the query builder to create the query and then call this function. Executing the query and formatting results should happen in a #pre_render callback.

Parameters

\Drupal\Core\Database\Query\SelectInterface $query: A select query object.

Return value

string A hash of the query arguments.

File

core/lib/Drupal/Core/Cache/Cache.php, line 182

Class

Cache

Helper methods for cache.

Namespace

Drupal\Core\Cache

Code

public static function keyFromQuery(SelectInterface $query) {
  $query
    ->preExecute();
  $keys = [
    (string) $query,
    $query
      ->getArguments(),
  ];
  return hash('sha256', serialize($keys));
}