Djedi CMS jinja2 node tag

gistfile1.py

# coding=utf-8
from string import strip
import textwrap
import cio
from djedi.templatetags.djedi_tags import render_node
from jinja2 import nodes
from jinja2.ext import Extension
from jinja2.filters import do_mark_safe
from jinja2.nodes import Name, Const


class DjediNodeExtension(Extension):

    tags = set(['node', 'blocknode'])

    def parse(self, parser):
        tag_name = parser.stream.current.value
        lineno = parser.stream.next().lineno

        args, kwargs = self.parse_args(parser)
        uri = args[0]

        body = []
        if tag_name == 'blocknode':
            body = parser.parse_statements(['name:endblocknode'], drop_needle=True)
            default = body[0].nodes[0].data
            default = default.strip('\n\r')
            default = textwrap.dedent(default)
            const_body = Const(default)
            kwargs.append(nodes.Keyword('default', const_body, lineno=const_body.lineno))

        call_method = self.call_method('_render', args=[uri], kwargs=kwargs).set_lineno(lineno)
        return nodes.CallBlock(call_method, [], [], body)

    def parse_args(self, parser):
        args = []
        kwargs = []
        require_comma = False

        while parser.stream.current.type != 'block_end':
            if require_comma:
                parser.stream.expect('comma')

            if parser.stream.current.type == 'name' and parser.stream.look().type == 'assign':
                key = parser.stream.current.value
                parser.stream.skip(2)
                value = parser.parse_expression()
                kwargs.append(nodes.Keyword(key, value, lineno=value.lineno))
            else:
                if kwargs:
                    parser.fail('Invalid argument syntax for Djedi tag',
                                parser.stream.current.lineno)
                args.append(parser.parse_expression())

            require_comma = True

        return args, kwargs

    def _render(self, uri, caller=None, **kwargs):
        default = kwargs.get('default')
        node = cio.get(uri, default=default)
        edit = kwargs.pop('edit', True)
        return do_mark_safe(render_node(node, context=kwargs, edit=edit))