"""

I really hate repeating myself. These are helpers that avoid typing the

whole thing over and over when implementing additional template tags

They help implementing tags of the following forms::

{% tag as var_name %}

{% tag of template_var as var_name %}

{% tag of template_var as var_name arg1,arg2,kwarg3=4 %}

"""

from django import template

def _parse_args(argstr, context=None):

try:

args = {}

for token in argstr.split(","):

if "=" in token:

k, v = token.split("=", 1)

if context:

try:

args[k] = template.Variable(v).resolve(context)

except template.VariableDoesNotExist:

args[k] = v

else:

args[k] = v

else:

args[token] = True

return args

except TypeError:

raise template.TemplateSyntaxError("Malformed arguments")

def do_simple_assignment_node_with_var_and_args_helper(cls):

def _func(parser, token):

try:

tag_name, of_, in_var_name, as_, var_name, args = token.contents.split()

except ValueError:

try:

tag_name, of_, in_var_name, as_, var_name = token.contents.split()

args = ""

except ValueError:

raise template.TemplateSyntaxError(

f"Invalid syntax for {cls.__name__} node: {token.contents}"

)

return cls(tag_name, in_var_name, var_name, args)

return _func

class SimpleAssignmentNodeWithVarAndArgs(template.Node):

def __init__(self, tag_name, in_var_name, var_name, args):

self.tag_name = tag_name

self.in_var = template.Variable(in_var_name)

self.var_name = var_name

self.args = args

def render(self, context):

self.render_context = context

try:

instance = self.in_var.resolve(context)

except template.VariableDoesNotExist:

context[self.var_name] = []

return ""

context[self.var_name] = self.what(instance, _parse_args(self.args, context))

return ""