def direct_to_template_subdir(request, template, subdir = None, **kwargs):
    """
    A wrapper around django's direct_to_template view. It prepend a
    given file path on to the template we are given. This lets us
    render templates in a sub-dir of the url pattern that matches this
    template.

    What do I mean?

    Take for example:

        url(r'^foo/(?P<template>.*\.html)$', direct_to_template,
            {'subdir' : 'subdir/'}),


    Which will template any url that matches <parent url>/foo/bar.html for any
    'bar'. The problem is if this is a sub-url pattern match this is going to
    look for the template "bar.html" when we may actually want it to get the
    template "<parent url>/foo/bar.html"

    Arguments:
    - `request`: django httprequest object... 
    - `template`: The template to render.
    - `subdir`: The subdir to prepend to the template.
    - `**kwargs`: kwargs to pass in to 
    """
    
    if subdir is not None:
        template = os.path.join(subdir,template)
    return direct_to_template(request, template, **kwargs)