from __future__ import absolute_import, division, unicode_literals
from six import text_type
from . import base
from ..constants import namespaces, voidElements
from ..constants import spaceCharacters
spaceCharacters = "".join(spaceCharacters)
[docs]class Filter(base.Filter):
"""Lints the token stream for errors
If it finds any errors, it'll raise an ``AssertionError``.
"""
[docs] def __init__(self, source, require_matching_tags=True):
"""Creates a Filter
:arg source: the source token stream
:arg require_matching_tags: whether or not to require matching tags
"""
super(Filter, self).__init__(source)
self.require_matching_tags = require_matching_tags
def __iter__(self):
open_elements = []
for token in base.Filter.__iter__(self):
type = token["type"]
if type in ("StartTag", "EmptyTag"):
namespace = token["namespace"]
name = token["name"]
assert namespace is None or isinstance(namespace, text_type)
assert namespace != ""
assert isinstance(name, text_type)
assert name != ""
assert isinstance(token["data"], dict)
if (not namespace or namespace == namespaces["html"]) and name in voidElements:
assert type == "EmptyTag"
else:
assert type == "StartTag"
if type == "StartTag" and self.require_matching_tags:
open_elements.append((namespace, name))
for (namespace, name), value in token["data"].items():
assert namespace is None or isinstance(namespace, text_type)
assert namespace != ""
assert isinstance(name, text_type)
assert name != ""
assert isinstance(value, text_type)
elif type == "EndTag":
namespace = token["namespace"]
name = token["name"]
assert namespace is None or isinstance(namespace, text_type)
assert namespace != ""
assert isinstance(name, text_type)
assert name != ""
if (not namespace or namespace == namespaces["html"]) and name in voidElements:
assert False, "Void element reported as EndTag token: %(tag)s" % {"tag": name}
elif self.require_matching_tags:
start = open_elements.pop()
assert start == (namespace, name)
elif type == "Comment":
data = token["data"]
assert isinstance(data, text_type)
elif type in ("Characters", "SpaceCharacters"):
data = token["data"]
assert isinstance(data, text_type)
assert data != ""
if type == "SpaceCharacters":
assert data.strip(spaceCharacters) == ""
elif type == "Doctype":
name = token["name"]
assert name is None or isinstance(name, text_type)
assert token["publicId"] is None or isinstance(name, text_type)
assert token["systemId"] is None or isinstance(name, text_type)
elif type == "Entity":
assert isinstance(token["name"], text_type)
elif type == "SerializerError":
assert isinstance(token["data"], text_type)
else:
assert False, "Unknown token type: %(type)s" % {"type": type}
yield token