django 1.5 - How to use variables inside static tag

I'm currently migrating all the static files references in my project to the new {% static %} tag that django 1.5 introduced, but I'm having a problem, in some places I use variables to get the content. With the new tag I can't, is there any way to solve this?

Current code:

<img src="{{ STATIC_URL }}/assets/flags/{{ request.LANGUAGE_CODE }}.gif" alt="{% trans 'Language' %}" title="{% trans 'Language' %}" />

What it should be (this doesn't work):

<img src="{% static 'assets/flags/{{ request.LANGUAGE_CODE }}.gif' %}" alt="{% trans 'Language' %}" title="{% trans 'Language' %}" />

You should be able to concatenate strings with the add template filter:

{% with 'assets/flags/'|add:request.LANGUAGE_CODE|add:'.gif' as image_static %}
  {% static image_static %}
{% endwith %}

What you are trying to do doesn't work with the static template tag because it takes either a string or a variable only:

{% static "myapp/css/base.css" %}
{% static variable_with_path %}
{% static "myapp/css/base.css" as admin_base_css %}
{% static variable_with_path as varname %}

For what it's worth, I think this is the easiest way:

<img src="{% static 'assets/flags/'|add:request.LANGUAGE_CODE|add:'.gif' %}" ... >

This is and old question and I'm not sure if this method could be done back then, But now, in Django 2.0 this seems to work fine for me.

a cleaner way is to set the {% static %} as a variable from the beginning of the html so we can use it in any way we want.

{% load static %}
{% static "" as baseUrl %}
<img src="{{ baseUrl }}/img/{{p.id}}"></img>