gnu-social/templates/attachments/view.html.twig

{% set thumbnail_parameters = {'id': attachment.getId(), 'w': config('thumbnail','width'), 'h': config('thumbnail','height')} %}
{% set handled = false %}
{% for block in handle_event('ViewAttachment' ~ attachment.getMimetypeMajor() | capitalize , {'attachment': attachment, 'thumbnail_parameters': thumbnail_parameters}) %}
    {% set handled = true %}
    {{ block | raw }}
{% endfor %}
{% if not handled %}
    <div>
        <i> <a href="{{ path('attachment_show', {'id': attachment.getId()}) }}">{{ attachment.getFilename() }}</a> </i>
    </div>
{% endif %}