from __future__ import print_function

from twisted.web.template import (
    XMLFile, TagLoader, Element, renderer, flattenString)
from twisted.python.filepath import FilePath

class WidgetsElement(Element):
    loader = XMLFile(FilePath('subviews-1.xml'))

    widgetData = ['gadget', 'contraption', 'gizmo', 'doohickey']

    @renderer
    def widgets(self, request, tag):
        for widget in self.widgetData:
            yield WidgetElement(TagLoader(tag), widget)

class WidgetElement(Element):
    def __init__(self, loader, name):
        Element.__init__(self, loader)
        self._name = name

    @renderer
    def name(self, request, tag):
        return tag(self._name)

def printResult(result):
    print(result)

flattenString(None, WidgetsElement()).addCallback(printResult)