@view_config(renderer='templates/form.pt', name='mapping')
    @demonstrate('Mapping Widget')
    def mapping(self):
        class Mapping(colander.Schema):
            name = colander.SchemaNode(
                colander.String(),
                description='Content name')
            date = colander.SchemaNode(
                colander.Date(),
                widget=deform.widget.DatePartsWidget(),
                description='Content date')
        class Schema(colander.Schema):
            number = colander.SchemaNode(
                colander.Integer())
            mapping = Mapping()
        schema = Schema()
        form = deform.Form(schema, buttons=('submit',))
        return self.render_form(form)