def get_form_class(self, request, plugins, plugin):
        """
        Returns a subclass of Form to be used by this plugin
        """
        widget = self.get_editor_widget(
            request=request,
            plugins=plugins,
            plugin=plugin,
        )

        instance = plugin.get_plugin_instance()[0]

        if instance:
            context = RequestContext(request)
            context['request'] = request
            rendered_text = plugin_tags_to_admin_html(
                text=instance.body,
                context=context,
            )
        else:
            rendered_text = None

        # We avoid mutating the Form declared above by subclassing
        class TextPluginForm(self.form):
            body = CharField(widget=widget, required=False)

            def __init__(self, *args, **kwargs):
                initial = kwargs.pop('initial', {})

                if rendered_text:
                    initial['body'] = rendered_text
                super(TextPluginForm, self).__init__(*args, initial=initial, **kwargs)
        return TextPluginForm
Returns a subclass of Form to be used by this plugin