def render(self, context):
url = self.url.resolve(context)
parts = url.split("?")
url = parts[0]
original_query = QueryDict("&".join(parts[1:])).copy()
query = MultiValueDict(dict((k, v.resolve(context)) for k, v in six.iteritems(self.kwargs)))
args_to_set = []
args_to_remove = []
for arg in self.args:
k = arg.resolve(context)
if k.startswith("-"):
args_to_remove.append(k[1:])
else:
args_to_set.append(k)
kwargs_to_set = MultiValueDict()
kwargs_to_add = MultiValueDict()
kwargs_to_remove = MultiValueDict()
for (k, v) in query.lists():
# make sure val is a list of strings
val = map(str, v if isinstance(v, list) else [v])
if k.startswith("+"):
kwargs_to_add.setlistdefault(k[1:]).extend(val)
elif k.startswith("-"):
kwargs_to_remove.setlistdefault(k[1:]).extend(val)
else:
kwargs_to_set.setlist(k, val)
filter_excluded_kwargs = lambda values: [
(k, list(set(v) - set(kwargs_to_remove.getlist(k))))
for k, v in values.iterlists()
if k not in args_to_remove
]
args = [arg for arg in args_to_set if arg not in args_to_remove]
kwargs = MultiValueDict()
for k, v in filter_excluded_kwargs(original_query):
kwargs.setlistdefault(k).extend(v if isinstance(v, list) else [v])
for k, v in filter_excluded_kwargs(kwargs_to_set):
kwargs.setlist(k, v)
for k, v in filter_excluded_kwargs(kwargs_to_add):
kwargs.setlistdefault(k).extend(v)
output = list(set(args))
for k, l in kwargs.lists():
output.extend(["%s=%s" % (k, v) if v else six.text_type(k) for v in l])
if output:
url = "?".join([url, "&".join(set(output))])
if self.asvar:
context[self.asvar] = url
return ""
else:
return url
