def compile_attribute_selector(selector: parser.AttributeSelector):
name = selector.lower_name
operator = selector.operator
value = selector.value and selector.value.lower()
if operator is None:
return lambda el: bool(el.attribute(name))
elif operator == "=":
return lambda el: el.attribute(name) == value
elif operator == "~=":
return lambda el: value in split_whitespace(el.attribute(name))
elif operator == "^=":
return lambda el: value and el.attribute(name).startswith(value)
elif operator == "$=":
return lambda el: value and el.attribute(name).endswith(value)
elif operator == "*=":
return lambda el: value and value in el.attribute(name)
elif operator == "|=":
def pipe_equal_matcher(el):
v = el.attribute(name)
return v == value or (v and v.startswith(value + "-"))
return pipe_equal_matcher
else:
raise parser.SelectorError("Unknown attribute operator", operator)
def compile_node(selector):
"""
Dynamic dispatch selector nodes.
Default behavior is a deny (no match).
"""
parser.SelectorError("Unknown selector", selector)
def compile_pseudo_class_selector(selector: parser.PseudoClassSelector):
name = selector.name
if name == "empty":
return lambda el: not next(el.children(), 0)
elif name in ("root", "hover", "focus", "active", "drop"):
return lambda el: name in el.state()
else:
raise parser.SelectorError("Unknown pseudo-class", name)
def compile_functional_pseudo_class_selector(
selector: parser.FunctionalPseudoClassSelector, ):
name = selector.name
if name not in ("has", "is", "not"):
raise parser.SelectorError("Unknown pseudo-class", name)
sub_selectors = compile_selector_list(selector.arguments)
selector.specificity = max(spec for _, spec in sub_selectors)
if name == "has":
return lambda el: any(
any(sel(c) for sel, _ in sub_selectors) for c in descendants(el))
elif name == "is":
return lambda el: any(sel(el) for sel, _ in sub_selectors)
elif name == "not":
return lambda el: not any(sel(el) for sel, _ in sub_selectors)
def compile_combined_selector(selector: parser.CombinedSelector):
left_inside = compile_node(selector.left)
if selector.combinator == " ":
def left(el):
return any(left_inside(e) for e in ancestors(el))
elif selector.combinator == ">":
def left(el):
p = el.parent()
return p is not None and left_inside(p)
else:
raise parser.SelectorError("Unknown combinator", selector.combinator)
right = compile_node(selector.right)
return lambda el: right(el) and left(el)