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 callable|null $callback A valid PHP callback or null to set it later
 38:      * @param int           $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:      * Factory method for chainability
 55:      *
 56:      * @param callable|null $callback A valid PHP callback or null to set it later
 57:      * @param int           $status   The response status code
 58:      * @param array         $headers  An array of response headers
 59:      *
 60:      * @return StreamedResponse
 61:      */
 62:     public static function create($callback = null, $status = 200, $headers = array())
 63:     {
 64:         return new static($callback, $status, $headers);
 65:     }
 66: 
 67:     /**
 68:      * Sets the PHP callback associated with this Response.
 69:      *
 70:      * @param callable $callback A valid PHP callback
 71:      *
 72:      * @throws \LogicException
 73:      */
 74:     public function setCallback($callback)
 75:     {
 76:         if (!is_callable($callback)) {
 77:             throw new \LogicException('The Response callback must be a valid PHP callable.');
 78:         }
 79:         $this->callback = $callback;
 80:     }
 81: 
 82:     /**
 83:      * {@inheritdoc}
 84:      *
 85:      * This method only sends the content once.
 86:      */
 87:     public function sendContent()
 88:     {
 89:         if ($this->streamed) {
 90:             return;
 91:         }
 92: 
 93:         $this->streamed = true;
 94: 
 95:         if (null === $this->callback) {
 96:             throw new \LogicException('The Response callback must not be null.');
 97:         }
 98: 
 99:         call_user_func($this->callback);
100:     }
101: 
102:     /**
103:      * {@inheritdoc}
104:      *
105:      * @throws \LogicException when the content is not null
106:      */
107:     public function setContent($content)
108:     {
109:         if (null !== $content) {
110:             throw new \LogicException('The content cannot be set on a StreamedResponse instance.');
111:         }
112:     }
113: 
114:     /**
115:      * {@inheritdoc}
116:      *
117:      * @return false
118:      */
119:     public function getContent()
120:     {
121:         return false;
122:     }
123: }
124: