CODEWITHSUNDEEP
imagesymfonyhttp-headerslistenerimagesource
Edgar Alfonso
Edgar Alfonso

Reputation: 685

Return Image as http-response from Listener Symfony2

This listener sends me reports on all kinds of exceptions that occur on the website. Sometimes I get reports of images that have been deleted but are still consulted by search engines and others.

I want to do, instead of displaying an error message " 404 Not Found " return the correct image. To do this I created a database table that stores the old links and new links of the images that have been deleted, moved or changed its name.

then, this listener find in db the links to fallen and gets the new links of images . The goal is to return the image as http-response with header content-type as image.

My code is:

class ExceptionListener
{
private $service_container;
private $router;

function __construct(Container $service_container, $router){
    $this->service_container = $service_container;
    $this->router = $router;
}

public function onKernelException(GetResponseForExceptionEvent $event){
    $exception = $event->getException();
    $request = $this->service_container->get('request');

    ...

    $document_root = $request->server->get('DOCUMENT_ROOT');
    $filename = realpath($document_root . '/'. '/path/to/new_image.jpg');
    $response = new \Symfony\Component\HttpFoundation\Response();
    $response->headers->set('Content-type',  'image/jpeg');
    $response->headers->set('Content-Disposition', 'inline; filename="' . basename($filename) . '";');
    $response->headers->set('Content-length', filesize($filename));
    $response->sendHeaders();
    $response->setContent(file_get_contents($filename));
    return $response;

    ...
}
}

The following error occurs:

browser screenshot

In the browser you can see a small box , it is as if trying to show the image but the image source could not be obtained . But if the same code is testing on controller , its working properly and the image is displayed .

in controller works fine

What can I do to return image from a listener ? thanks

Upvotes: 1

Views: 1177

Answers (1)

Jakub Zalas
Jakub Zalas

Reputation: 36191

There's few things wrong about the code snippet from your question.

Firstly, you should never use the request service. It's deprecated since Symfony 2.4 and was removed in Symfony 3.0. Use the request stack (request_stack) instead.

Secondly, do not send the response yourself, but let the framework do it. Symfony events system is designed for flexibility (see the docs). In your case it's enough to set the response on the event object.

Finally, you don't need the service container to access the request at all, as it's available on the event.

Moreover, instead of the standard Response class you can use the BinaryFileResponse. It's purpose is to serve files (have a look at the docs).

You can greatly simplify your listener:

use Symfony\Component\HttpFoundation\BinaryFileResponse;

class ExceptionListener
{
    private $router;

    function __construct($router)
    {
        $this->router = $router;
    }

    public function onKernelException(GetResponseForExceptionEvent $event)
    {
        $exception = $event->getException();
        // request is avialable on the event
        $request = $event->getRequest();

        // ...


        $file = 'path/to/file.txt';
        $response = new BinaryFileResponse($file);
        // ... set response parameters ...

        // finally, set the response on your event
        $event->setResponse($response);
    }
}

Upvotes: 1

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