StorageInterface.php

<?php

/**
 * @file
 * Definition of Drupal\Core\Config\StorageInterface.
 */
namespace Drupal\Core\Config;


/**
 * Defines an interface for configuration storage controllers.
 *
 * Classes implementing this interface allow reading and writing configuration
 * data from and to the storage.
 */
interface StorageInterface {

  /**
   * Returns whether a configuration object exists.
   *
   * @param string $name
   *   The name of a configuration object to test.
   *
   * @return bool
   *   TRUE if the configuration object exists, FALSE otherwise.
   */
  public function exists($name);

  /**
   * Reads configuration data from the storage.
   *
   * @param string $name
   *   The name of a configuration object to load.
   *
   * @return array|bool
   *   The configuration data stored for the configuration object name. If no
   *   configuration data exists for the given name, FALSE is returned.
   */
  public function read($name);

  /**
   * Writes configuration data to the storage.
   *
   * @param string $name
   *   The name of a configuration object to save.
   * @param array $data
   *   The configuration data to write.
   *
   * @return bool
   *   TRUE on success, FALSE in case of an error.
   */
  public function write($name, array $data);

  /**
   * Deletes a configuration object from the storage.
   *
   * @param string $name
   *   The name of a configuration object to delete.
   *
   * @return bool
   *   TRUE on success, FALSE otherwise.
   */
  public function delete($name);

  /**
   * Renames a configuration object in the storage.
   *
   * @param string $name
   *   The name of a configuration object to rename.
   * @param string $new_name
   *   The new name of a configuration object.
   *
   * @return bool
   *   TRUE on success, FALSE otherwise.
   */
  public function rename($name, $new_name);

  /**
   * Encodes configuration data into the storage-specific format.
   *
   * @param array $data
   *   The configuration data to encode.
   *
   * @return string
   *   The encoded configuration data.
   *
   * This is a publicly accessible static method to allow for alternative
   * usages in data conversion scripts and also tests.
   */
  public function encode($data);

  /**
   * Decodes configuration data from the storage-specific format.
   *
   * @param string $raw
   *   The raw configuration data string to decode.
   *
   * @return array
   *   The decoded configuration data as an associative array.
   *
   * This is a publicly accessible static method to allow for alternative
   * usages in data conversion scripts and also tests.
   */
  public function decode($raw);

  /**
   * Gets configuration object names starting with a given prefix.
   *
   * Given the following configuration objects:
   * - node.type.article
   * - node.type.page
   *
   * Passing the prefix 'node.type.' will return an array containing the above
   * names.
   *
   * @param string $prefix
   *   (optional) The prefix to search for. If omitted, all configuration object
   *   names that exist are returned.
   *
   * @return array
   *   An array containing matching configuration object names.
   */
  public function listAll($prefix = '');

}