101 lines
3.9 KiB
Python
101 lines
3.9 KiB
Python
"""
|
|
Handle CSS stylesheets.
|
|
|
|
"""
|
|
|
|
import cssselect2
|
|
import tinycss2
|
|
|
|
from .url import parse_url
|
|
|
|
|
|
def find_stylesheets(tree):
|
|
"""Find the stylesheets included in ``tree``."""
|
|
# TODO: support contentStyleType on <svg>
|
|
default_type = 'text/css'
|
|
for element in tree.xml_tree.iter():
|
|
# http://www.w3.org/TR/SVG/styling.html#StyleElement
|
|
if (element.tag == '{http://www.w3.org/2000/svg}style' and
|
|
element.get('type', default_type) == 'text/css' and
|
|
element.text):
|
|
# TODO: pass href for relative URLs
|
|
# TODO: support media types
|
|
# TODO: what if <style> has children elements?
|
|
yield tinycss2.parse_stylesheet(
|
|
element.text, skip_comments=True, skip_whitespace=True)
|
|
|
|
|
|
def find_stylesheets_rules(tree, stylesheet_rules, url):
|
|
"""Find the rules in a stylesheet."""
|
|
for rule in stylesheet_rules:
|
|
if rule.type == 'at-rule':
|
|
if rule.lower_at_keyword == 'import' and rule.content is None:
|
|
# TODO: support media types in @import
|
|
url_token = tinycss2.parse_one_component_value(rule.prelude)
|
|
if url_token.type not in ('string', 'url'):
|
|
continue
|
|
css_url = parse_url(url_token.value, url)
|
|
stylesheet = tinycss2.parse_stylesheet(
|
|
tree.fetch_url(css_url, 'text/css').decode('utf-8'))
|
|
for rule in find_stylesheets_rules(
|
|
tree, stylesheet, css_url.geturl()):
|
|
yield rule
|
|
# TODO: support media types
|
|
# if rule.lower_at_keyword == 'media':
|
|
if rule.type == 'qualified-rule':
|
|
yield rule
|
|
# TODO: warn on error
|
|
# if rule.type == 'error':
|
|
|
|
|
|
def parse_declarations(input):
|
|
normal_declarations = []
|
|
important_declarations = []
|
|
for declaration in tinycss2.parse_declaration_list(input):
|
|
# TODO: warn on error
|
|
# if declaration.type == 'error':
|
|
if (declaration.type == 'declaration' and
|
|
not declaration.name.startswith('-')):
|
|
# Serializing perfectly good tokens just to re-parse them later :(
|
|
value = tinycss2.serialize(declaration.value).strip()
|
|
declarations = (
|
|
important_declarations if declaration.important
|
|
else normal_declarations)
|
|
declarations.append((declaration.lower_name, value))
|
|
return normal_declarations, important_declarations
|
|
|
|
|
|
def parse_stylesheets(tree, url):
|
|
"""Find and parse the stylesheets in ``tree``.
|
|
|
|
Return two :class:`cssselect2.Matcher` objects,
|
|
for normal and !important declarations.
|
|
|
|
"""
|
|
normal_matcher = cssselect2.Matcher()
|
|
important_matcher = cssselect2.Matcher()
|
|
for stylesheet in find_stylesheets(tree):
|
|
for rule in find_stylesheets_rules(tree, stylesheet, url):
|
|
normal_declarations, important_declarations = parse_declarations(
|
|
rule.content)
|
|
for selector in cssselect2.compile_selector_list(rule.prelude):
|
|
if (selector.pseudo_element is None and
|
|
not selector.never_matches):
|
|
if normal_declarations:
|
|
normal_matcher.add_selector(
|
|
selector, normal_declarations)
|
|
if important_declarations:
|
|
important_matcher.add_selector(
|
|
selector, important_declarations)
|
|
return normal_matcher, important_matcher
|
|
|
|
|
|
def get_declarations(rule):
|
|
"""Get the declarations in ``rule``."""
|
|
if rule.type == 'qualified-rule':
|
|
for declaration in tinycss2.parse_declaration_list(
|
|
rule.content, skip_comments=True, skip_whitespace=True):
|
|
value = ''.join(part.serialize() for part in declaration.value)
|
|
# TODO: filter out invalid values
|
|
yield declaration.lower_name, value, declaration.important
|