Switch-Case in the Django Template Langauge

switch.py

# -*- coding: utf-8 -*-
"""
In Django 1.4+ you should probably use if-elif-else-endif instead of this. 

Usage:

    {% switch somevar %}
        {% case 1 %}
            ...
        {% endcase %}
        {% case 2 %}
            ...
        {% endcase %}
    {% endswitch %}
"""
from classytags.arguments import Argument, Flag
from classytags.core import Options, Tag
from django.template.base import Library

register = Library()

def check(a, b, checktype):
    if a == b:
        return True
    if checktype:
        return False
    try:
        return unicode(a) == unicode(b)
    except:
        return False

class Switch(Tag):
    options = Options(
        Argument('value'),
        Flag('checktype', true_values=['checktype'], default=False),
        blocks=[('endswitch', 'nodelist')],
    )
    
    def render_tag(self, context, value, checktype, nodelist):
        output = []
        for node in nodelist:
            if isinstance(node, Case):
                if check(node.value.resolve(context), value, checktype):
                    output.append(node.render(context, real=True))
            else:
                output.append(node.render(context))
        return u''.join(output)

register.tag(Switch)

class Case(Tag):
    options = Options(
        Argument('value', resolve=False),
        blocks=[('endcase', 'nodelist')],
    )
    
    def __init__(self, *args, **kwargs):
        super(Case, self).__init__(*args, **kwargs)
        self.value = self.kwargs['value']
        
    def render(self, context, real=False):
        """
        Prevent rendering outside a switch statement
        """
        if real:
            return super(Case, self).render(context)
        else:
            return u''
    
    def render_tag(self, context, value, nodelist):
        return nodelist.render(context)

register.tag(Case)