NullStorage.php

<?php

namespace Drupal\Core\Config;


/**
 * Defines a stub storage.
 *
 * This storage is always empty; the controller reads and writes nothing.
 *
 * The stub implementation is needed for synchronizing configuration during
 * installation of a module, in which case all configuration being shipped with
 * the module is known to be new. Therefore, the module installation process is
 * able to short-circuit the full diff against the active configuration; the
 * diff would yield all currently available configuration as items to remove,
 * since they do not exist in the module's default configuration directory.
 *
 * This also can be used for testing purposes.
 */
class NullStorage implements StorageInterface {
    
    /**
     * The storage collection.
     *
     * @var string
     */
    protected $collection;
    
    /**
     * Constructs a new NullStorage.
     *
     * @param string $collection
     *   (optional) The collection to store configuration in. Defaults to the
     *   default collection.
     */
    public function __construct($collection = StorageInterface::DEFAULT_COLLECTION) {
        $this->collection = $collection;
    }
    
    /**
     * {@inheritdoc}
     */
    public function exists($name) {
        return FALSE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function read($name) {
        return [];
    }
    
    /**
     * {@inheritdoc}
     */
    public function readMultiple(array $names) {
        return [];
    }
    
    /**
     * {@inheritdoc}
     */
    public function write($name, array $data) {
        return FALSE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function delete($name) {
        return FALSE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function rename($name, $new_name) {
        return FALSE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function encode($data) {
        return $data;
    }
    
    /**
     * {@inheritdoc}
     */
    public function decode($raw) {
        return $raw;
    }
    
    /**
     * {@inheritdoc}
     */
    public function listAll($prefix = '') {
        return [];
    }
    
    /**
     * {@inheritdoc}
     */
    public function deleteAll($prefix = '') {
        return FALSE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function createCollection($collection) {
        return new static($collection);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getAllCollectionNames() {
        // Returns only non empty collections.
        return [];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCollectionName() {
        return $this->collection;
    }

}