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Support complex selector in not #124

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82 changes: 78 additions & 4 deletions cssselect/parser.py
Original file line number Diff line number Diff line change
Expand Up @@ -238,12 +238,22 @@ class Negation(object):
Represents selector:not(subselector)
"""

def __init__(self, selector, subselector):
def __init__(self, selector, subselector, combinator=None, subselector2=None):
self.selector = selector
self.subselector = subselector
self.combinator = combinator
self.subselector2 = subselector2

def __repr__(self):
return "%s[%r:not(%r)]" % (self.__class__.__name__, self.selector, self.subselector)
if self.combinator is None and self.subselector2 is None:
return "%s[%r:not(%r)]" % (self.__class__.__name__, self.selector, self.subselector)
return "%s[%r:not(%r %s %r)]" % (
self.__class__.__name__,
self.selector,
self.subselector,
self.combinator.value,
self.subselector2.parsed_tree,
)

def canonical(self):
subsel = self.subselector.canonical()
Expand All @@ -257,6 +267,41 @@ def specificity(self):
return a1 + a2, b1 + b2, c1 + c2


class Relation(object):
"""
Represents selector:has(subselector)
"""

def __init__(self, selector, combinator, subselector):
self.selector = selector
self.combinator = combinator
self.subselector = subselector

def __repr__(self):
return "%s[%r:has(%r)]" % (
self.__class__.__name__,
self.selector,
self.subselector,
)

def canonical(self):
try:
subsel = self.subselector[0].canonical()
except TypeError:
subsel = self.subselector.canonical()
if len(subsel) > 1:
subsel = subsel.lstrip("*")
return "%s:has(%s)" % (self.selector.canonical(), subsel)

def specificity(self):
a1, b1, c1 = self.selector.specificity()
try:
a2, b2, c2 = self.subselector[-1].specificity()
except TypeError:
a2, b2, c2 = self.subselector.specificity()
return a1 + a2, b1 + b2, c1 + c2


class Matching(object):
"""
Represents selector:is(selector_list)
Expand Down Expand Up @@ -579,9 +624,15 @@ def parse_simple_selector(stream, inside_negation=False):
"Got pseudo-element ::%s inside :not() at %s"
% (argument_pseudo_element, next.pos)
)
combinator = arguments = None
if next != ("DELIM", ")"):
raise SelectorSyntaxError("Expected ')', got %s" % (next,))
result = Negation(result, argument)
stream.skip_whitespace()
combinator, arguments = parse_relative_selector(stream)
result = Negation(result, argument, combinator, arguments)
elif ident.lower() == "has":
combinator, arguments = parse_relative_selector(stream)
result = Relation(result, combinator, arguments)

elif ident.lower() in ("matches", "is"):
selectors = parse_simple_selector_arguments(stream)
result = Matching(result, selectors)
Expand All @@ -607,6 +658,29 @@ def parse_arguments(stream):
raise SelectorSyntaxError("Expected an argument, got %s" % (next,))


def parse_relative_selector(stream):
stream.skip_whitespace()
subselector = ""
next = stream.next()

if next in [("DELIM", "+"), ("DELIM", "-"), ("DELIM", ">"), ("DELIM", "~")]:
combinator = next
stream.skip_whitespace()
next = stream.next()
else:
combinator = Token("DELIM", " ", pos=0)

while 1:
if next.type in ("IDENT", "STRING", "NUMBER") or next in [("DELIM", "."), ("DELIM", "*")]:
subselector += next.value
elif next == ("DELIM", ")"):
result = parse(subselector)
return combinator, result[0]
else:
raise SelectorSyntaxError("Expected an argument, got %s" % (next,))
next = stream.next()


def parse_simple_selector_arguments(stream):
arguments = []
while 1:
Expand Down
69 changes: 65 additions & 4 deletions cssselect/xpath.py
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@

import sys
import re
import copy

from cssselect.parser import parse, parse_series, SelectorError

Expand Down Expand Up @@ -75,13 +76,13 @@ def add_star_prefix(self):
"""
self.path += "*/"

def join(self, combiner, other):
def join(self, combiner, other, closing_combiner=None):
path = _unicode(self) + combiner
# Any "star prefix" is redundant when joining.
if other.path != "*/":
path += other.path
self.path = path
self.element = other.element
self.element = other.element + closing_combiner if closing_combiner else other.element
self.condition = other.condition
return self

Expand Down Expand Up @@ -269,12 +270,32 @@ def xpath_combinedselector(self, combined):
def xpath_negation(self, negation):
xpath = self.xpath(negation.selector)
sub_xpath = self.xpath(negation.subselector)
sub_xpath.add_name_test()
if sub_xpath.condition:
if negation.combinator is not None and negation.subselector2 is not None:
sub2_xpath = self.xpath(negation.subselector2.parsed_tree)
method = getattr(
self,
"xpath_negation_%s_combinator"
% self.combinator_mapping[negation.combinator.value],
)
return method(xpath, sub_xpath, sub2_xpath)
elif sub_xpath.condition:
sub_xpath.add_name_test()
return xpath.add_condition("not(%s)" % sub_xpath.condition)
else:
sub_xpath.add_name_test()
return xpath.add_condition("0")

def xpath_relation(self, relation):
xpath = self.xpath(relation.selector)
combinator = relation.combinator
subselector = relation.subselector
right = self.xpath(subselector.parsed_tree)
method = getattr(
self,
"xpath_relation_%s_combinator" % self.combinator_mapping[combinator.value],
)
return method(xpath, right)

def xpath_matching(self, matching):
xpath = self.xpath(matching.selector)
exprs = [self.xpath(selector) for selector in matching.selector_list]
Expand Down Expand Up @@ -376,6 +397,46 @@ def xpath_indirect_adjacent_combinator(self, left, right):
"""right is a sibling after left, immediately or not"""
return left.join("/following-sibling::", right)

def xpath_relation_descendant_combinator(self, left, right):
"""right is a child, grand-child or further descendant of left; select left"""
return left.join("[descendant::", right, closing_combiner="]")

def xpath_relation_child_combinator(self, left, right):
"""right is an immediate child of left; select left"""
return left.join("[./", right, closing_combiner="]")

def xpath_relation_direct_adjacent_combinator(self, left, right):
"""right is a sibling immediately after left; select left"""
xpath = left.add_condition(
"following-sibling::*[(name() = '{}') and (position() = 1)]".format(right.element)
)
return xpath

def xpath_relation_indirect_adjacent_combinator(self, left, right):
"""right is a sibling after left, immediately or not; select left"""
return left.join("[following-sibling::", right, closing_combiner="]")

def xpath_negation_descendant_combinator(self, xpath, left, right):
xpath.add_condition('not(name()="%s" and ancestor::*[name()="%s"])' % (right, left))
return xpath

def xpath_negation_child_combinator(self, xpath, left, right):
xpath.add_condition('not(name()="%s" and parent::*[name()="%s"])' % (right, left))
return xpath

def xpath_negation_direct_adjacent_combinator(self, xpath, left, right):
xpath.add_condition(
'not(name()="%s" and following-sibling::*[position()=1 and name()="%s"])'
% (right, left)
)
return xpath

def xpath_negation_indirect_adjacent_combinator(self, xpath, left, right):
xpath.add_condition(
'not(name()="%s" and following-sibling::*[name()="%s"])' % (right, left)
)
return xpath

# Function: dispatch by function/pseudo-class name

def xpath_nth_child_function(self, xpath, function, last=False, add_name_test=True):
Expand Down
39 changes: 39 additions & 0 deletions tests/test_cssselect.py
Original file line number Diff line number Diff line change
Expand Up @@ -145,9 +145,16 @@ def parse_many(first, *others):
assert parse_many("a:lang(fr)") == ["Function[Element[a]:lang(['fr'])]"]
assert parse_many('div:contains("foo")') == ["Function[Element[div]:contains(['foo'])]"]
assert parse_many("div#foobar") == ["Hash[Element[div]#foobar]"]
assert parse_many(":not(a > b)") == ["Negation[Element[*]:not(Element[a] > Element[b])]"]
assert parse_many(":not(a + b)") == ["Negation[Element[*]:not(Element[a] + Element[b])]"]
assert parse_many(":not(a ~ b)") == ["Negation[Element[*]:not(Element[a] ~ Element[b])]"]
assert parse_many(":not(a b)") == ["Negation[Element[*]:not(Element[a] Element[b])]"]
assert parse_many("div:not(div.foo)") == [
"Negation[Element[div]:not(Class[Element[div].foo])]"
]
assert parse_many("div:has(div.foo)") == [
"Relation[Element[div]:has(Selector[Class[Element[div].foo]])]"
]
assert parse_many("div:is(.foo, #bar)") == [
"Matching[Element[div]:is(Class[Element[*].foo], Hash[Element[*]#bar])]"
]
Expand Down Expand Up @@ -279,6 +286,11 @@ def specificity(css):
assert specificity(":not(:empty)") == (0, 1, 0)
assert specificity(":not(#foo)") == (1, 0, 0)

assert specificity(":has(*)") == (0, 0, 0)
assert specificity(":has(foo)") == (0, 0, 1)
assert specificity(":has(.foo)") == (0, 1, 0)
assert specificity(":has(> foo)") == (0, 0, 1)

assert specificity(":is(.foo, #bar)") == (1, 0, 0)
assert specificity(":is(:hover, :visited)") == (0, 1, 0)

Expand Down Expand Up @@ -315,6 +327,9 @@ def css2css(css, res=None):
css2css(":not(*[foo])", ":not([foo])")
css2css(":not(:empty)")
css2css(":not(#foo)")
css2css(":has(*)")
css2css(":has(foo)")
css2css(":has(*.foo)", ":has(.foo)")
css2css(":is(#bar, .foo)")
css2css(":is(:focused, :visited)")
css2css("foo:empty")
Expand Down Expand Up @@ -379,6 +394,10 @@ def get_error(css):
)
assert get_error("> div p") == ("Expected selector, got <DELIM '>' at 0>")

# Unsupported :has() with several arguments
assert get_error(":has(a, b)") == ("Expected an argument, got <DELIM ',' at 6>")
assert get_error(":has()") == ("Expected selector, got <EOF at 0>")

def test_translation(self):
def xpath(css):
return _unicode(GenericTranslator().css_to_xpath(css, prefix=""))
Expand Down Expand Up @@ -453,6 +472,24 @@ def xpath(css):
assert xpath("e:EmPTY") == ("e[not(*) and not(string-length())]")
assert xpath("e:root") == ("e[not(parent::*)]")
assert xpath("e:hover") == ("e[0]") # never matches
assert xpath("*:not(a > b)") == (
'*[not(name()="b" and parent::*[name()="a"])]'
) # select anything that is not b or doesn't have a parent a
assert xpath("*:not(a + b)") == (
'*[not(name()="b" and following-sibling::*[position()=1 and name()="a"])]'
) # select anything that is not b or doesn't have an immediate sibling a
assert xpath("*:not(a ~ b)") == (
'*[not(name()="b" and following-sibling::*[name()="a"])]'
) # select anything that is not b or doesn't have a sibling a
assert xpath("*:not(a b)") == (
'*[not(name()="b" and ancestor::*[name()="a"])]'
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This change should also be applied to other 3 combinators.

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@annbgn annbgn Aug 17, 2021

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So I suppose the tests should look like this:

assert xpath("*:not(a > b)") == '*[not(name()="b" and parent::*[name()="a"])]'  # select anything that is not b or doesn't have a parent a
assert xpath("*:not(a + b)") == '*[not(name()="b" and following-sibling::*[position()=1 and name()="a"])]'  # select anything that is not b or doesn't have an immediate sibling a
assert xpath("*:not(a ~ b)") == '*[not(name()="b" and following-sibling::*[name()="a"])]'  # select anything that is not b or doesn't have a sibling a
assert xpath("*:not(a b)") == '*[not(name()="b" and ancestor::*[name()="a"])]'  # select anything that is not b or doesn't have an ancestor a

please correct me if i'm wrong

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I think that's correct.

) # select anything that is not b or doesn't have an ancestor a
assert xpath("e:has(> f)") == "e[./f]"
assert xpath("e:has(f)") == "e[descendant::f]"
assert xpath("e:has(~ f)") == "e[following-sibling::f]"
assert (
xpath("e:has(+ f)") == "e[following-sibling::*[(name() = 'f') and (position() = 1)]]"
)
assert xpath('e:contains("foo")') == ("e[contains(., 'foo')]")
assert xpath("e:ConTains(foo)") == ("e[contains(., 'foo')]")
assert xpath("e.warning") == (
Expand Down Expand Up @@ -863,6 +900,8 @@ def pcss(main, *selectors, **kwargs):
"sixth-li",
"seventh-li",
]
assert pcss("link:has(*)") == []
assert pcss("ol:has(div)") == ["first-ol"]
assert pcss(":is(#first-li, #second-li)") == ["first-li", "second-li"]
assert pcss("a:is(#name-anchor, #tag-anchor)") == ["name-anchor", "tag-anchor"]
assert pcss(":is(.c)") == ["first-ol", "third-li", "fourth-li"]
Expand Down