1: <?php
  2: 
  3: /*
  4:  * This file is part of the Symfony package.
  5:  *
  6:  * (c) Fabien Potencier <fabien@symfony.com>
  7:  *
  8:  * For the full copyright and license information, please view the LICENSE
  9:  * file that was distributed with this source code.
 10:  */
 11: 
 12: namespace Symfony\Component\HttpFoundation;
 13: 
 14: /**
 15:  * StreamedResponse represents a streamed HTTP response.
 16:  *
 17:  * A StreamedResponse uses a callback for its content.
 18:  *
 19:  * The callback should use the standard PHP functions like echo
 20:  * to stream the response back to the client. The flush() method
 21:  * can also be used if needed.
 22:  *
 23:  * @see flush()
 24:  *
 25:  * @author Fabien Potencier <fabien@symfony.com>
 26:  *
 27:  * @api
 28:  */
 29: class StreamedResponse extends Response
 30: {
 31:     protected $callback;
 32:     protected $streamed;
 33: 
 34:     /**
 35:      * Constructor.
 36:      *
 37:      * @param mixed   $callback A valid PHP callback
 38:      * @param integer $status   The response status code
 39:      * @param array   $headers  An array of response headers
 40:      *
 41:      * @api
 42:      */
 43:     public function __construct($callback = null, $status = 200, $headers = array())
 44:     {
 45:         parent::__construct(null, $status, $headers);
 46: 
 47:         if (null !== $callback) {
 48:             $this->setCallback($callback);
 49:         }
 50:         $this->streamed = false;
 51:     }
 52: 
 53:     /**
 54:      * {@inheritDoc}
 55:      */
 56:     public static function create($callback = null, $status = 200, $headers = array())
 57:     {
 58:         return new static($callback, $status, $headers);
 59:     }
 60: 
 61:     /**
 62:      * Sets the PHP callback associated with this Response.
 63:      *
 64:      * @param mixed $callback A valid PHP callback
 65:      *
 66:      * @throws \LogicException
 67:      */
 68:     public function setCallback($callback)
 69:     {
 70:         if (!is_callable($callback)) {
 71:             throw new \LogicException('The Response callback must be a valid PHP callable.');
 72:         }
 73:         $this->callback = $callback;
 74:     }
 75: 
 76:     /**
 77:      * {@inheritdoc}
 78:      */
 79:     public function prepare(Request $request)
 80:     {
 81:         $this->headers->set('Cache-Control', 'no-cache');
 82: 
 83:         return parent::prepare($request);
 84:     }
 85: 
 86:     /**
 87:      * {@inheritdoc}
 88:      *
 89:      * This method only sends the content once.
 90:      */
 91:     public function sendContent()
 92:     {
 93:         if ($this->streamed) {
 94:             return;
 95:         }
 96: 
 97:         $this->streamed = true;
 98: 
 99:         if (null === $this->callback) {
100:             throw new \LogicException('The Response callback must not be null.');
101:         }
102: 
103:         call_user_func($this->callback);
104:     }
105: 
106:     /**
107:      * {@inheritdoc}
108:      *
109:      * @throws \LogicException when the content is not null
110:      */
111:     public function setContent($content)
112:     {
113:         if (null !== $content) {
114:             throw new \LogicException('The content cannot be set on a StreamedResponse instance.');
115:         }
116:     }
117: 
118:     /**
119:      * {@inheritdoc}
120:      *
121:      * @return false
122:      */
123:     public function getContent()
124:     {
125:         return false;
126:     }
127: }
128: