* * For the full copyright and license information, please view the LICENSE * file that was distributed with this source code. */ namespace Symfony\Component\HttpFoundation; /** * StreamedResponse represents a streamed HTTP response. * * A StreamedResponse uses a callback for its content. * * The callback should use the standard PHP functions like echo * to stream the response back to the client. The flush() method * can also be used if needed. * * @see flush() * * @author Fabien Potencier * * @api */ class StreamedResponse extends Response { protected $callback; protected $streamed; /** * Constructor. * * @param callable|null $callback A valid PHP callback or null to set it later * @param integer $status The response status code * @param array $headers An array of response headers * * @api */ public function __construct($callback = null, $status = 200, $headers = array()) { parent::__construct(null, $status, $headers); if (null !== $callback) { $this->setCallback($callback); } $this->streamed = false; } /** * Factory method for chainability * * @param callable|null $callback A valid PHP callback or null to set it later * @param integer $status The response status code * @param array $headers An array of response headers * * @return StreamedResponse */ public static function create($callback = null, $status = 200, $headers = array()) { return new static($callback, $status, $headers); } /** * Sets the PHP callback associated with this Response. * * @param callable $callback A valid PHP callback * * @throws \LogicException */ public function setCallback($callback) { if (!is_callable($callback)) { throw new \LogicException('The Response callback must be a valid PHP callable.'); } $this->callback = $callback; } /** * {@inheritdoc} */ public function prepare(Request $request) { $this->headers->set('Cache-Control', 'no-cache'); return parent::prepare($request); } /** * {@inheritdoc} * * This method only sends the content once. */ public function sendContent() { if ($this->streamed) { return; } $this->streamed = true; if (null === $this->callback) { throw new \LogicException('The Response callback must not be null.'); } call_user_func($this->callback); } /** * {@inheritdoc} * * @throws \LogicException when the content is not null */ public function setContent($content) { if (null !== $content) { throw new \LogicException('The content cannot be set on a StreamedResponse instance.'); } } /** * {@inheritdoc} * * @return false */ public function getContent() { return false; } }