abstract class ReadOnlyStream in Drupal 8

Defines a read-only Drupal stream wrapper base class.

This class provides a minimal-read only stream wrapper implementation. Specifically, it only implements the writing classes and read classes where we need to restrict 'write-capable' arguments.

Drupal\Core\StreamWrapper\ReadOnlyStream implementations need to implement all the read-related classes.

Hierarchy

• class \Drupal\Core\StreamWrapper\ReadOnlyStream implements StreamWrapperInterface

File

core/lib/Drupal/Core/StreamWrapper/ReadOnlyStream.php, line 15

Namespace

Drupal\Core\StreamWrapper

abstract class ReadOnlyStream implements StreamWrapperInterface {

  /**
   * Stream context resource.
   *
   * @var resource
   */
  public $context;

  /**
   * A generic resource handle.
   *
   * @var resource
   */
  public $handle = NULL;

  /**
   * Instance URI (stream).
   *
   * A stream is referenced as "scheme://target".
   *
   * @var string
   */
  protected $uri;

  /**
   * {@inheritdoc}
   */
  public function setUri($uri) {
    $this->uri = $uri;
  }

  /**
   * {@inheritdoc}
   */
  public function getUri() {
    return $this->uri;
  }

  /**
   * Support for fopen(), file_get_contents(), etc.
   *
   * Any write modes will be rejected, as this is a read-only stream wrapper.
   *
   * @param string $uri
   *   A string containing the URI to the file to open.
   * @param int $mode
   *   The file mode, only strict readonly modes are supported.
   * @param int $options
   *   A bit mask of STREAM_USE_PATH and STREAM_REPORT_ERRORS.
   * @param string $opened_path
   *   A string containing the path actually opened.
   *
   * @return bool
   *   TRUE if $mode denotes a readonly mode and the file was opened
   *   successfully, FALSE otherwise.
   *
   * @see http://php.net/manual/streamwrapper.stream-open.php
   */
  public function stream_open($uri, $mode, $options, &$opened_path) {
    if (!in_array($mode, [
      'r',
      'rb',
      'rt',
    ])) {
      if ($options & STREAM_REPORT_ERRORS) {
        trigger_error('stream_open() write modes not supported for read-only stream wrappers', E_USER_WARNING);
      }
      return FALSE;
    }
    $this->uri = $uri;
    $path = $this
      ->getLocalPath();
    $this->handle = $options & STREAM_REPORT_ERRORS ? fopen($path, $mode) : @fopen($path, $mode);
    if ($this->handle !== FALSE && $options & STREAM_USE_PATH) {
      $opened_path = $path;
    }
    return (bool) $this->handle;
  }

  /**
   * Support for flock().
   *
   * An exclusive lock attempt will be rejected, as this is a read-only stream
   * wrapper.
   *
   * @param int $operation
   *   One of the following:
   *   - LOCK_SH to acquire a shared lock (reader).
   *   - LOCK_EX to acquire an exclusive lock (writer).
   *   - LOCK_UN to release a lock (shared or exclusive).
   *   - LOCK_NB if you don't want flock() to block while locking (not
   *     supported on Windows).
   *
   * @return bool
   *   Return FALSE for an exclusive lock (writer), as this is a read-only
   *   stream wrapper.  Return the result of flock() for other valid operations.
   *   Defaults to TRUE if an invalid operation is passed.
   *
   * @see http://php.net/manual/streamwrapper.stream-lock.php
   */
  public function stream_lock($operation) {
    if (in_array($operation, [
      LOCK_EX,
      LOCK_EX | LOCK_NB,
    ])) {
      trigger_error('stream_lock() exclusive lock operations not supported for read-only stream wrappers', E_USER_WARNING);
      return FALSE;
    }
    if (in_array($operation, [
      LOCK_SH,
      LOCK_UN,
      LOCK_SH | LOCK_NB,
    ])) {
      return flock($this->handle, $operation);
    }
    return TRUE;
  }

  /**
   * Support for fwrite(), file_put_contents() etc.
   *
   * Data will not be written as this is a read-only stream wrapper.
   *
   * @param string $data
   *   The string to be written.
   *
   * @return bool
   *   FALSE as data will not be written.
   *
   * @see http://php.net/manual/streamwrapper.stream-write.php
   */
  public function stream_write($data) {
    trigger_error('stream_write() not supported for read-only stream wrappers', E_USER_WARNING);
    return FALSE;
  }

  /**
   * Support for fflush().
   *
   * Nothing will be output to the file, as this is a read-only stream wrapper.
   * However as stream_flush is called during stream_close we should not trigger
   * an error.
   *
   * @return bool
   *   FALSE, as no data will be stored.
   *
   * @see http://php.net/manual/streamwrapper.stream-flush.php
   */
  public function stream_flush() {
    return FALSE;
  }

  /**
   * {@inheritdoc}
   *
   * Does not change meta data as this is a read-only stream wrapper.
   */
  public function stream_metadata($uri, $option, $value) {
    trigger_error('stream_metadata() not supported for read-only stream wrappers', E_USER_WARNING);
    return FALSE;
  }

  /**
   * {@inheritdoc}
   */
  public function stream_truncate($new_size) {
    trigger_error('stream_truncate() not supported for read-only stream wrappers', E_USER_WARNING);
    return FALSE;
  }

  /**
   * Support for unlink().
   *
   * The file will not be deleted from the stream as this is a read-only stream
   * wrapper.
   *
   * @param string $uri
   *   A string containing the uri to the resource to delete.
   *
   * @return bool
   *   TRUE so that file_delete() will remove db reference to file. File is not
   *   actually deleted.
   *
   * @see http://php.net/manual/streamwrapper.unlink.php
   */
  public function unlink($uri) {
    trigger_error('unlink() not supported for read-only stream wrappers', E_USER_WARNING);
    return TRUE;
  }

  /**
   * Support for rename().
   *
   * This file will not be renamed as this is a read-only stream wrapper.
   *
   * @param string $from_uri
   *   The uri to the file to rename.
   * @param string $to_uri
   *   The new uri for file.
   *
   * @return bool
   *   FALSE as file will never be renamed.
   *
   * @see http://php.net/manual/streamwrapper.rename.php
   */
  public function rename($from_uri, $to_uri) {
    trigger_error('rename() not supported for read-only stream wrappers', E_USER_WARNING);
    return FALSE;
  }

  /**
   * Support for mkdir().
   *
   * Directory will never be created as this is a read-only stream wrapper.
   *
   * @param string $uri
   *   A string containing the URI to the directory to create.
   * @param int $mode
   *   Permission flags - see mkdir().
   * @param int $options
   *   A bit mask of STREAM_REPORT_ERRORS and STREAM_MKDIR_RECURSIVE.
   *
   * @return bool
   *   FALSE as directory will never be created.
   *
   * @see http://php.net/manual/streamwrapper.mkdir.php
   */
  public function mkdir($uri, $mode, $options) {
    trigger_error('mkdir() not supported for read-only stream wrappers', E_USER_WARNING);
    return FALSE;
  }

  /**
   * Support for rmdir().
   *
   * Directory will never be deleted as this is a read-only stream wrapper.
   *
   * @param string $uri
   *   A string containing the URI to the directory to delete.
   * @param int $options
   *   A bit mask of STREAM_REPORT_ERRORS.
   *
   * @return bool
   *   FALSE as directory will never be deleted.
   *
   * @see http://php.net/manual/streamwrapper.rmdir.php
   */
  public function rmdir($uri, $options) {
    trigger_error('rmdir() not supported for read-only stream wrappers', E_USER_WARNING);
    return FALSE;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
PhpStreamWrapperInterface::dir_closedir	public	function		1
PhpStreamWrapperInterface::dir_opendir	public	function		1
PhpStreamWrapperInterface::dir_readdir	public	function		1
PhpStreamWrapperInterface::dir_rewinddir	public	function		1
PhpStreamWrapperInterface::stream_cast	public	function	Retrieve the underlying stream resource.	1
PhpStreamWrapperInterface::stream_close	public	function	Closes stream.	1
PhpStreamWrapperInterface::stream_eof	public	function		1
PhpStreamWrapperInterface::stream_read	public	function		1
PhpStreamWrapperInterface::stream_seek	public	function	Seeks to specific location in a stream.	1
PhpStreamWrapperInterface::stream_set_option	public	function	Change stream options.	1
PhpStreamWrapperInterface::stream_stat	public	function		1
PhpStreamWrapperInterface::stream_tell	public	function		1
PhpStreamWrapperInterface::url_stat	public	function		1
ReadOnlyStream::$context	public	property	Stream context resource.
ReadOnlyStream::$handle	public	property	A generic resource handle.
ReadOnlyStream::$uri	protected	property	Instance URI (stream).
ReadOnlyStream::getUri	public	function	Returns the stream resource URI. Overrides StreamWrapperInterface::getUri
ReadOnlyStream::mkdir	public	function	Support for mkdir(). Overrides PhpStreamWrapperInterface::mkdir
ReadOnlyStream::rename	public	function	Support for rename(). Overrides PhpStreamWrapperInterface::rename
ReadOnlyStream::rmdir	public	function	Support for rmdir(). Overrides PhpStreamWrapperInterface::rmdir
ReadOnlyStream::setUri	public	function	Sets the absolute stream resource URI. Overrides StreamWrapperInterface::setUri
ReadOnlyStream::stream_flush	public	function	Support for fflush(). Overrides PhpStreamWrapperInterface::stream_flush
ReadOnlyStream::stream_lock	public	function	Support for flock(). Overrides PhpStreamWrapperInterface::stream_lock
ReadOnlyStream::stream_metadata	public	function	Does not change meta data as this is a read-only stream wrapper. Overrides PhpStreamWrapperInterface::stream_metadata
ReadOnlyStream::stream_open	public	function	Support for fopen(), file_get_contents(), etc. Overrides PhpStreamWrapperInterface::stream_open
ReadOnlyStream::stream_truncate	public	function	Truncate stream. Overrides PhpStreamWrapperInterface::stream_truncate
ReadOnlyStream::stream_write	public	function	Support for fwrite(), file_put_contents() etc. Overrides PhpStreamWrapperInterface::stream_write
ReadOnlyStream::unlink	public	function	Support for unlink(). Overrides PhpStreamWrapperInterface::unlink
StreamWrapperInterface::ALL		constant	A filter that matches all wrappers.
StreamWrapperInterface::dirname	public	function	Gets the name of the directory from a given path.	1
StreamWrapperInterface::getDescription	public	function	Returns the description of the stream wrapper for use in the UI.	6
StreamWrapperInterface::getExternalUrl	public	function	Returns a web accessible URL for the resource.	6
StreamWrapperInterface::getName	public	function	Returns the name of the stream wrapper for use in the UI.	6
StreamWrapperInterface::getType	public static	function	Returns the type of stream wrapper.	1
StreamWrapperInterface::HIDDEN		constant	Defines the stream wrapper bit flag for a hidden file.
StreamWrapperInterface::LOCAL		constant	Refers to a local file system location.
StreamWrapperInterface::LOCAL_HIDDEN		constant	Hidden, readable and writable using local files.
StreamWrapperInterface::LOCAL_NORMAL		constant	Visible, readable and writable using local files.
StreamWrapperInterface::NORMAL		constant	This is the default 'type' flag. This does not include StreamWrapperInterface::LOCAL, because PHP grants a greater trust level to local files (for example, they can be used in an "include" statement, regardless of the…
StreamWrapperInterface::READ		constant	Wrapper is readable (almost always true).
StreamWrapperInterface::READ_VISIBLE		constant	Visible and read-only.
StreamWrapperInterface::realpath	public	function	Returns canonical, absolute path of the resource.	1
StreamWrapperInterface::VISIBLE		constant	Exposed in the UI and potentially web accessible.
StreamWrapperInterface::WRITE		constant	Wrapper is writable.
StreamWrapperInterface::WRITE_VISIBLE		constant	Visible, readable and writable.