class MediaLibraryState in Drupal 8

A value object for the media library state.

When the media library is opened it needs several parameters to work properly. These parameters are normally extracted from the current URL, then retrieved from and managed by the MediaLibraryState value object. The following parameters are required in order to open the media library:

• media_library_opener_id: The ID of a container service which implements \Drupal\media_library\MediaLibraryOpenerInterface and is responsible for interacting with the media library on behalf of the "thing" (e.g., a field widget or text editor button) which opened it.
• media_library_allowed_types: The media types available in the library can be restricted to a list of allowed types. This should be an array of media type IDs.
• media_library_selected_type: The media library contains tabs to navigate between the different media types. The selected type contains the ID of the media type whose tab that should be opened.
• media_library_remaining: When the opener wants to limit the amount of media items that can be selected, it can pass the number of remaining slots. When the number of remaining slots is a negative number, an unlimited amount of items can be selected.

This object can also carry an optional opener-specific array of arbitrary values, under the media_library_opener_parameters key. These values are included in the hash generated by ::getHash(), so the end user cannot tamper with them either.

Hierarchy

• class \Drupal\media_library\MediaLibraryState extends \Symfony\Component\HttpFoundation\ParameterBag

See also

\Drupal\media_library\MediaLibraryOpenerInterface

8 files declare their use of MediaLibraryState

DrupalMediaLibrary.php in core/modules/media_library/src/Plugin/CKEditorPlugin/DrupalMediaLibrary.php

MediaLibraryAccessTest.php in core/modules/media_library/tests/src/Kernel/MediaLibraryAccessTest.php

MediaLibraryAddFormTest.php in core/modules/media_library/tests/src/Kernel/MediaLibraryAddFormTest.php

MediaLibrarySelectForm.php in core/modules/media_library/src/Plugin/views/field/MediaLibrarySelectForm.php

MediaLibraryStateTest.php in core/modules/media_library/tests/src/Kernel/MediaLibraryStateTest.php

... See full list

File

core/modules/media_library/src/MediaLibraryState.php, line 40

Namespace

Drupal\media_library

class MediaLibraryState extends ParameterBag {

  /**
   * {@inheritdoc}
   */
  public function __construct(array $parameters = []) {
    $this
      ->validateRequiredParameters($parameters['media_library_opener_id'], $parameters['media_library_allowed_types'], $parameters['media_library_selected_type'], $parameters['media_library_remaining']);
    $parameters += [
      'media_library_opener_parameters' => [],
    ];
    parent::__construct($parameters);
    $this
      ->set('hash', $this
      ->getHash());
  }

  /**
   * Creates a new MediaLibraryState object.
   *
   * @param string $opener_id
   *   The opener ID.
   * @param string[] $allowed_media_type_ids
   *   The allowed media type IDs.
   * @param string $selected_type_id
   *   The selected media type ID.
   * @param int $remaining_slots
   *   The number of remaining items the user is allowed to select or add in the
   *   library.
   * @param array $opener_parameters
   *   (optional) Any additional opener-specific parameter values.
   *
   * @return static
   *   A state object.
   */
  public static function create($opener_id, array $allowed_media_type_ids, $selected_type_id, $remaining_slots, array $opener_parameters = []) {
    $state = new static([
      'media_library_opener_id' => $opener_id,
      'media_library_allowed_types' => $allowed_media_type_ids,
      'media_library_selected_type' => $selected_type_id,
      'media_library_remaining' => $remaining_slots,
      'media_library_opener_parameters' => $opener_parameters,
    ]);
    return $state;
  }

  /**
   * Get the media library state from a request.
   *
   * @param \Symfony\Component\HttpFoundation\Request $request
   *   The request.
   *
   * @return static
   *   A state object.
   *
   * @throws \Symfony\Component\HttpKernel\Exception\BadRequestHttpException
   *   Thrown when the hash query parameter is invalid.
   */
  public static function fromRequest(Request $request) {
    $query = $request->query;

    // Create a MediaLibraryState object through the create method to make sure
    // all validation runs.
    $state = static::create($query
      ->get('media_library_opener_id'), $query
      ->get('media_library_allowed_types', []), $query
      ->get('media_library_selected_type'), $query
      ->get('media_library_remaining'), $query
      ->get('media_library_opener_parameters', []));

    // The request parameters need to contain a valid hash to prevent a
    // malicious user modifying the query string to attempt to access
    // inaccessible information.
    if (!$state
      ->isValidHash($query
      ->get('hash'))) {
      throw new BadRequestHttpException("Invalid media library parameters specified.");
    }

    // Once we have validated the required parameters, we restore the parameters
    // from the request since there might be additional values.
    $state
      ->replace($query
      ->all());
    return $state;
  }

  /**
   * Validates the required parameters for a new MediaLibraryState object.
   *
   * @param string $opener_id
   *   The media library opener service ID.
   * @param string[] $allowed_media_type_ids
   *   The allowed media type IDs.
   * @param string $selected_type_id
   *   The selected media type ID.
   * @param int $remaining_slots
   *   The number of remaining items the user is allowed to select or add in the
   *   library.
   *
   * @throws \InvalidArgumentException
   *   If one of the passed arguments is missing or does not pass the
   *   validation.
   */
  protected function validateRequiredParameters($opener_id, array $allowed_media_type_ids, $selected_type_id, $remaining_slots) {

    // The opener ID must be a non-empty string.
    if (!is_string($opener_id) || empty(trim($opener_id))) {
      throw new \InvalidArgumentException('The opener ID parameter is required and must be a string.');
    }

    // The allowed media type IDs must be an array of non-empty strings.
    if (empty($allowed_media_type_ids) || !is_array($allowed_media_type_ids)) {
      throw new \InvalidArgumentException('The allowed types parameter is required and must be an array of strings.');
    }
    foreach ($allowed_media_type_ids as $allowed_media_type_id) {
      if (!is_string($allowed_media_type_id) || empty(trim($allowed_media_type_id))) {
        throw new \InvalidArgumentException('The allowed types parameter is required and must be an array of strings.');
      }
    }

    // The selected type ID must be a non-empty string.
    if (!is_string($selected_type_id) || empty(trim($selected_type_id))) {
      throw new \InvalidArgumentException('The selected type parameter is required and must be a string.');
    }

    // The selected type ID must be present in the list of allowed types.
    if (!in_array($selected_type_id, $allowed_media_type_ids, TRUE)) {
      throw new \InvalidArgumentException('The selected type parameter must be present in the list of allowed types.');
    }

    // The remaining slots must be numeric.
    if (!is_numeric($remaining_slots)) {
      throw new \InvalidArgumentException('The remaining slots parameter is required and must be numeric.');
    }
  }

  /**
   * Get the hash for the state object.
   *
   * @return string
   *   The hashed parameters.
   */
  public function getHash() {

    // Create a hash from the required state parameters and the serialized
    // optional opener-specific parameters. Sort the allowed types and
    // opener parameters so that differences in order do not result in
    // different hashes.
    $allowed_media_type_ids = array_values($this
      ->getAllowedTypeIds());
    sort($allowed_media_type_ids);
    $opener_parameters = $this
      ->getOpenerParameters();
    ksort($opener_parameters);
    $hash = implode(':', [
      $this
        ->getOpenerId(),
      implode(':', $allowed_media_type_ids),
      $this
        ->getSelectedTypeId(),
      $this
        ->getAvailableSlots(),
      serialize($opener_parameters),
    ]);
    return Crypt::hmacBase64($hash, \Drupal::service('private_key')
      ->get() . Settings::getHashSalt());
  }

  /**
   * Validate a hash for the state object.
   *
   * @param string $hash
   *   The hash to validate.
   *
   * @return string
   *   The hashed parameters.
   */
  public function isValidHash($hash) {
    return hash_equals($this
      ->getHash(), $hash);
  }

  /**
   * Returns the ID of the media library opener service.
   *
   * @return string
   *   The media library opener service ID.
   */
  public function getOpenerId() {
    return $this
      ->get('media_library_opener_id');
  }

  /**
   * Returns the media type IDs which can be selected.
   *
   * @return string[]
   *   The media type IDs.
   */
  public function getAllowedTypeIds() {
    return $this
      ->get('media_library_allowed_types');
  }

  /**
   * Returns the selected media type.
   *
   * @return string
   *   The selected media type.
   */
  public function getSelectedTypeId() {
    return $this
      ->get('media_library_selected_type');
  }

  /**
   * Determines if additional media items can be selected.
   *
   * @return bool
   *   TRUE if additional items can be selected, otherwise FALSE.
   */
  public function hasSlotsAvailable() {
    return $this
      ->getAvailableSlots() !== 0;
  }

  /**
   * Returns the number of additional media items that can be selected.
   *
   * When the value is not available in the URL the default is 0. When a
   * negative integer is passed, an unlimited amount of media items can be
   * selected.
   *
   * @return int
   *   The number of additional media items that can be selected.
   */
  public function getAvailableSlots() {
    return $this
      ->getInt('media_library_remaining');
  }

  /**
   * Returns all opener-specific parameter values.
   *
   * @return array
   *   An associative array of all opener-specific parameter values.
   */
  public function getOpenerParameters() {
    return $this
      ->get('media_library_opener_parameters', []);
  }

}

Members

Name	Modifiers	Type	Description	Overrides
MediaLibraryState::create	public static	function	Creates a new MediaLibraryState object.
MediaLibraryState::fromRequest	public static	function	Get the media library state from a request.
MediaLibraryState::getAllowedTypeIds	public	function	Returns the media type IDs which can be selected.
MediaLibraryState::getAvailableSlots	public	function	Returns the number of additional media items that can be selected.
MediaLibraryState::getHash	public	function	Get the hash for the state object.
MediaLibraryState::getOpenerId	public	function	Returns the ID of the media library opener service.
MediaLibraryState::getOpenerParameters	public	function	Returns all opener-specific parameter values.
MediaLibraryState::getSelectedTypeId	public	function	Returns the selected media type.
MediaLibraryState::hasSlotsAvailable	public	function	Determines if additional media items can be selected.
MediaLibraryState::isValidHash	public	function	Validate a hash for the state object.
MediaLibraryState::validateRequiredParameters	protected	function	Validates the required parameters for a new MediaLibraryState object.
MediaLibraryState::__construct	public	function	Constructor.