[Shopware] Check if a media exists in the template

modifer.swkweMediaExists.php

<?php

function smarty_modifier_swkweMediaExists($mediaPath)
{
    $mediaService = Shopware()->Container()->get('shopware_media.media_service');

    if ($mediaService->has($mediaPath)) {
        return $mediaPath;
    } else {
        return '';
    }
}

Drop the file in /themes/Frontend/<MyTheme>/_private/smarty/, use it on a media path like the following:

{if $path|swkweMediaExists}
    {$path}
{/if}

or

{$path = $path|swkweMediaExists}