Fixed #625 -- Added template-tag decorators simple_tag and inclusion_tag....

from django.core.template import Context, Node, TemplateSyntaxError, register_tag, resolve_variable

from django.core.template_loader import get_template

from django.utils.functional import curry

from inspect import getargspec

def generic_tag_compiler(params, defaults, name, node_class, parser, token):

    "Returns a template.Node subclass."

    bits = token.contents.split()[1:]

    bmax = len(params)

    def_len = defaults and len(defaults) or 0

    bmin = bmax - def_len

    if(len(bits) < bmin or len(bits) > bmax):

        if bmin == bmax:

            message = "%s takes %s arguments" % (name, bmin)

        else:

            message = "%s takes between %s and %s arguments" % (name, bmin, bmax)

        raise TemplateSyntaxError, message

    return node_class(bits)

def simple_tag(func):

    (params, xx, xxx, defaults) = getargspec(func)

    class SimpleNode(Node):

        def __init__(self, vars_to_resolve):

            self.vars_to_resolve = vars_to_resolve

        def render(self, context):

            resolved_vars = [resolve_variable(var, context) for var in self.vars_to_resolve]

            return func(*resolved_vars)

    compile_func = curry(generic_tag_compiler, params, defaults, func.__name__, SimpleNode)

    compile_func.__doc__ = func.__doc__

    register_tag(func.__name__, compile_func)

    return func

def inclusion_tag(file_name, context_class=Context, takes_context=False):

    def dec(func):

        (params, xx, xxx, defaults) = getargspec(func)

        if takes_context:

            if params[0] == 'context':

                params = params[1:]

            else:

                raise TemplateSyntaxError, "Any tag function decorated with takes_context=True must have a first argument of 'context'"

        class InclusionNode(Node):

            def __init__(self, vars_to_resolve):

                self.vars_to_resolve = vars_to_resolve

            def render(self, context):

                resolved_vars = [resolve_variable(var, context) for var in self.vars_to_resolve]

                if takes_context:

                    args = [context] + resolved_vars

                else:

                    args = resolved_vars

                dict = func(*args)

                if not getattr(self, 'nodelist', False):

                    t = get_template(file_name)

                    self.nodelist = t.nodelist

                return self.nodelist.render(context_class(dict))

        compile_func = curry(generic_tag_compiler, params, defaults, func.__name__, InclusionNode)

        compile_func.__doc__ = func.__doc__

        register_tag(func.__name__, compile_func)

        return func

    return dec