<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* 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() function
* can also be used if needed.
*
* @see flush()
*
* @author Fabien Potencier <fabien@symfony.com>
*/
class StreamedResponse extends Response
{
protected $callback;
protected $streamed;
private $headersSent;
/**
* @param callable|null $callback A valid PHP callback or null to set it later
* @param int $status The response status code
* @param array $headers An array of response headers
*/
public function __construct(callable $callback = null, $status = 200, $headers = [])
{
parent::__construct(null, $status, $headers);
if (null !== $callback) {
$this->setCallback($callback);
}
$this->streamed = false;
$this->headersSent = false;
}
/**
* Factory method for chainability.
*
* @param callable|null $callback A valid PHP callback or null to set it later
* @param int $status The response status code
* @param array $headers An array of response headers
*
* @return static
*/
public static function create($callback = null, $status = 200, $headers = [])
{
return new static($callback, $status, $headers);
}
/**
* Sets the PHP callback associated with this Response.
*
* @param callable $callback A valid PHP callback
*
* @return $this
*/
public function setCallback(callable $callback)
{
$this->callback = $callback;
return $this;
}
/**
* {@inheritdoc}
*
* This method only sends the headers once.
*
* @return $this
*/
public function sendHeaders()
{
if ($this->headersSent) {
return $this;
}
$this->headersSent = true;
return parent::sendHeaders();
}
/**
* {@inheritdoc}
*
* This method only sends the content once.
*
* @return $this
*/
public function sendContent()
{
if ($this->streamed) {
return $this;
}
$this->streamed = true;
if (null === $this->callback) {
throw new \LogicException('The Response callback must not be null.');
}
\call_user_func($this->callback);
return $this;
}
/**
* {@inheritdoc}
*
* @throws \LogicException when the content is not null
*
* @return $this
*/
public function setContent($content)
{
if (null !== $content) {
throw new \LogicException('The content cannot be set on a StreamedResponse instance.');
}
$this->streamed = true;
return $this;
}
/**
* {@inheritdoc}
*/
public function getContent()
{
return false;
}
}