def post(self, request, relation_html_id):
        """
        Update plugin modifications.

        If modifications are correct return confirmation message
        and the new render of the layout section;
        if not, return the plugin form with error messages

        Parameters :
          - relation_html_id : PluginRelation Id

        POST parameters :
          - form fields
          - csrf token
        """
        pk = check_object_html_id(relation_html_id)[1]
        try:
            plugin_relation = PluginRelation.objects.filter(
                pages__website__exact=request.website, 
                id__exact=pk)[0]
        except __HOLE__:
            raise Http404
        # Create the plugin form
        plugin = plugin_relation.content_object
        PluginFormClass = plugin.get_admin_form()
        form = PluginFormClass(request.POST, instance=plugin)

        if form.is_valid():
            plugin = form.save()
            placeholder_slug_items = check_placeholder_html_id(
                plugin_relation.placeholder_slug)
            layout_section_slug = placeholder_slug_items[0]
            rendering_context = RenderingContext(request)
            html_rendering = rendering_context.get_html_layout(layout_section_slug)

            response = Response(status.HTTP_200_OK,
                                {"msg": MESSAGES.get('item_edit_success',""),
                                 'html': html_rendering,
                                 'layout_section_slug': layout_section_slug})

            return self.render(response)
        
        else:            
            # Invalid form => 400 BAD REQUEST
            # with forms (and errors..)
            html = render_to_string('administration/plugin/plugin-edit.html',
                                    {'form': form,
                                     'plugin': plugin,
                                     'plugin_relation_html_id': relation_html_id},
                                    context_instance = RequestContext(request))
            
            raise ErrorResponse(status.HTTP_400_BAD_REQUEST,
                                {'msg': MESSAGES.get('invalid_data', ""),
                                 'html': html})
dataset/ETHPy150Open ionyse/ionyweb/ionyweb/administration/views/plugin.py/PluginView.post