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Add Custom Media File Extension

Add Custom Media File Extension


You might have come across the fact, that you cannot just upload any type of media to Shopware by using the Media module in the Administration. If that's the case for you, this guide will be the solution. It will provide an explanation on how you can add new allowed file extensions to Shopware using a plugin.


As most of our plugin guides, this guide was also built upon our Plugin base guide. Furthermore, you'll have to know about adding classes to the Dependency injection container and about using a subscriber in order to Listen to events.

Adding a custom extension

In this section, we're going to take care of allowing a new extension to Shopware first, without letting Shopware know exactly what kind of file this new extension represents (Images, videos, documents, ...).

For this to work, all you have to do is to register to the MediaFileExtensionWhitelistEvent event, which can be found here. This is of course done via a subscriber.

Have a look at the following code example:

// <plugin root>/src/Service/Subscriber.php
<?php declare(strict_types=1);

namespace Swag\BasicExample\Service;

use Shopware\Core\Content\Media\Event\MediaFileExtensionWhitelistEvent;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

class Subscriber implements EventSubscriberInterface
    public static function getSubscribedEvents(): array
        return [
            MediaFileExtensionWhitelistEvent::class => 'addEntryToFileExtensionWhitelist'

    public function addEntryToFileExtensionWhitelist(MediaFileExtensionWhitelistEvent $event): void
        $whiteList = $event->getWhitelist();
        $whiteList[] = 'img';


You can use the method getWhitelist of the $event variable to get the current whitelist, which is just a plain array of extensions. Therefore you can add new array entries and then set the array back to the $event instance by using the respective setter method setWhitelist.

And that's it already! Shopware will now allow uploading files with the extension .img.

Recognising the new extension

There is another thing you most likely want to do here. While you can add new extensions like mentioned above, Shopware does not automatically recognise which kind of extension it is dealing with. Is it a new image extension and should be displayed as such? Is it a video file extension? Maybe a new kind of document?

In order to let Shopware know which kind of type we're dealing with, you can add a new TypeDetector class to let Shopware know about your new extension.

In the following example we'll imagine that we've added a new image extension called img, like we did above, and we're going to let Shopware know about it.

What we'll be doing now, is to add a custom TypeDetector class which returns an ImageType if the extension of the file to be checked matches our type detector. Have a look at the following example:

You will have to create a new class which implements from the interface TypeDetectorInterface. This will come with the requirement of having a detect method, which will return the respective media type.

Inside of the detect method, we're first checking if the file extension matches our allowed extensions, in this case only img. If that's not the case, just return the $previouslyDetectedType, which most likely comes from the DefaultTypeDetector and which tried to detect the type already by analysing the file's MIME-type.

If the extension does indeed match, we're for sure going to return ImageType here. Make sure to add flags to your media type, e.g. the transparent flag, or if it's an animated image.

You can find all available flags in their respective media type classes, e.g. here for the image media type.

Make sure to register your new type detector to the Dependency injection container by using the tag shopware.media_type.detector.

Shopware will now recognise your new image extension and handle your new file like an image.