from django.template import Library, Node, Variable, TemplateSyntaxError
from django.template.loader import get_template

register = Library()

class RandIncludeNode(Node):
    def __init__(self, template_names):
        from random import randrange
        templates = template_names.split(',')
        self.template_name = Variable(templates[randrange(len(templates))])


    def render(self, context):
        try:
            template_name = self.template_name.resolve(context)
            t = get_template(template_name)
            return t.render(context)
        except TemplateSyntaxError, e:
            if settings.TEMPLATE_DEBUG:
                raise
            return ''
        except:
            return '' # Fail silently for invalid included templates.
        
@register.tag
def rand_include(parser, token):
    """
    Loads a template and renders it with the current context.
    
    Example::
    
    {% include "foo/some_include" %}
    """
    bits = token.contents.split()
    if len(bits) != 2:
        raise TemplateSyntaxError, "%r tag takes one argument: the name of the template to be included" % bits[0]
    path = bits[1]
    return RandIncludeNode(bits[1])