from django.template.loader import render_to_string

from django import template

register = template.Library()

def make_from(form, fieldsets):
    for title, options in fieldsets:
        fields = [form[field] for field in options['fields'] if field not in form.Meta.exclude]
        if not fields:
            continue
        yield (title, fields, options)

@register.filter
def fieldsets(form):
    try:
        return render_to_string('parts/fieldset_form.html',
                                {'fieldsets': make_from(form, form.Meta.model._meta.admin.fields)})
    except AttributeError:
        return form