gistfile1.py

class TemplateWidget(object):
    "Uses a template to render the widget"
    def __init__(self, template, get_value_callable=None):
        self.template = template
        self.get_value_callable = get_value_callable

    def __call__(self, field, **kwargs):
        kwargs.update({'field': field})
        if self.get_value_callable:
            kwargs['value'] = self.get_value_callable(field)
        return render_to_string(self.template, kwargs)