eliott/ladybird
1
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird synced 2026-05-05 06:32:30 +02:00
Code Issues Packages Projects Releases Wiki Activity

LibWeb/CSS: Parse number as a type in attr()

Browse Source 
Dealing with `unit_name` as a separate variable was becoming unwieldy,
so I've also combined that into the `syntax` variant.

Corresponds to:
0e6b4ef33b
This commit is contained in:
Sam Atkins
2025-12-15 16:05:25 +00:00
parent e1b5a1c803
commit 0241652611
Notes: github-actions[bot] 2025-12-17 11:54:37 +00:00 
Author: https://github.com/AtkinsSJ
Commit: https://github.com/LadybirdBrowser/ladybird/commit/02416526113
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/7144
2 changed files with 76 additions and 36 deletions
Download Patch File Download Diff File Expand all files Collapse all files

106
Libraries/LibWeb/CSS/Parser/ArbitrarySubstitutionFunctions.cpp
View File

@@ -92,12 +92,15 @@ static Vector<ComponentValue> replace_an_attr_function(DOM::AbstractElement& ele
FlyString attribute_name;
struct RawString { };
Variant<Empty, NonnullOwnPtr<SyntaxNode>, RawString> syntax;
Optional<FlyString> unit_name;
struct RawStringKeyword { };
struct NumberKeyword { };
struct AttrUnit {
FlyString name;
};
Variant<Empty, NonnullOwnPtr<SyntaxNode>, RawStringKeyword, NumberKeyword, AttrUnit> syntax;
auto failure = [&] -> Vector<ComponentValue> {
// This is step 6, but defined here for convenience.
// This is step 7, but defined here for convenience.
// 1. If second arg is null, and syntax was omitted, return an empty CSS <string>.
if (!second_argument.has_value() && syntax.has<Empty>())
@@ -124,22 +127,23 @@ static Vector<ComponentValue> replace_an_attr_function(DOM::AbstractElement& ele
attribute_name = first_argument_tokens.consume_a_token().token().ident();
first_argument_tokens.discard_whitespace();
// <attr-type> = type( <syntax> ) | raw-string | <attr-unit>
// <attr-type> = type( <syntax> ) | raw-string | number | <attr-unit>
if (first_argument_tokens.next_token().is(Token::Type::Ident)) {
auto const& syntax_ident = first_argument_tokens.next_token().token().ident();
if (syntax_ident.equals_ignoring_ascii_case("raw-string"sv)) {
first_argument_tokens.discard_a_token(); // raw-string
syntax = RawString {};
syntax = RawStringKeyword {};
} else if (syntax_ident.equals_ignoring_ascii_case("number"sv)) {
first_argument_tokens.discard_a_token(); // number
syntax = NumberKeyword {};
} else if (dimension_for_unit(syntax_ident).has_value()) {
syntax = TypeSyntaxNode::create("number"_fly_string).release_nonnull<SyntaxNode>();
unit_name = first_argument_tokens.consume_a_token().token().ident();
syntax = AttrUnit { first_argument_tokens.consume_a_token().token().ident() };
} else {
return failure();
}
} else if (first_argument_tokens.next_token().is_delim('%')) {
first_argument_tokens.discard_a_token(); // %
syntax = TypeSyntaxNode::create("number"_fly_string).release_nonnull<SyntaxNode>();
unit_name = "%"_fly_string;
syntax = AttrUnit { "%"_fly_string };
} else if (first_argument_tokens.next_token().is_function("type"sv)) {
auto const& type_function = first_argument_tokens.consume_a_token().function();
if (auto parsed_syntax = parse_as_syntax(type_function.value)) {
@@ -158,16 +162,70 @@ static Vector<ComponentValue> replace_an_attr_function(DOM::AbstractElement& ele
if (!attribute_value.has_value())
return failure();
// 4. If syntax is null or the keyword raw-string, return a CSS <string> whose value is attr value.
// 4. If syntax is the keyword number or an <attr-unit> value, parse attr value against <attr-type>.
// If that succeeds, return the result; otherwise, jump to the last step (labeled FAILURE).
// NOTE: No parsing or modification of any kind is performed on the value.
auto parse_as_number = [&]() -> RefPtr<NumberStyleValue const> {
auto parser = Parser::create(ParsingParams { element.element().document() }, attribute_value.value());
auto unsubstituted_values = parser.parse_as_list_of_component_values();
auto syntax_node = TypeSyntaxNode::create("number"_fly_string);
auto parsed_value = parse_with_a_syntax(ParsingParams { element.document() }, unsubstituted_values, *syntax_node, element);
if (parsed_value->is_guaranteed_invalid())
return {};
// FIXME: The spec is ambiguous about what we should do for non-number-literals.
// Chromium treats them as invalid, so copy that for now.
// Spec issue: https://github.com/w3c/csswg-drafts/issues/12479
if (!parsed_value->is_number())
return {};
return parsed_value->as_number();
};
bool return_from_step_4 = false;
auto step_4_result = syntax.visit(
// https://drafts.csswg.org/css-values-5/#ref-for-typedef-attr-type%E2%91%A0
[&](NumberKeyword) -> Optional<Vector<ComponentValue>> {
// If given as the number keyword, it causes the attribute’s literal value, after stripping leading and
// trailing whitespace, to be parsed as a <number-token>. Values that fail to parse trigger fallback.
return_from_step_4 = true;
auto parsed_number = parse_as_number();
if (!parsed_number)
return {};
return Vector<ComponentValue> { Token::create_number(Number { Number::Type::Number, parsed_number->number() }) };
},
[&](AttrUnit const& attr_unit) -> Optional<Vector<ComponentValue>> {
// If given as an <attr-unit> value, the value is first parsed as if number keyword was specified, then the
// resulting numeric value is turned into a dimension with the corresponding unit, or a percentage if % was
// given. Same as for number <attr-type>, values that do not correspond to the <number-token> production
// trigger fallback.
return_from_step_4 = true;
auto parsed_number = parse_as_number();
if (!parsed_number)
return {};
if (attr_unit.name == "%"_fly_string)
return Vector<ComponentValue> { Token::create_percentage(Number { Number::Type::Number, parsed_number->number() }) };
return Vector<ComponentValue> { Token::create_dimension(parsed_number->number(), attr_unit.name) };
},
[&](auto&) -> Optional<Vector<ComponentValue>> {
return OptionalNone {};
});
if (return_from_step_4) {
if (step_4_result.has_value())
return step_4_result.release_value();
return failure();
}
// 5. If syntax is null or the keyword raw-string, return a CSS <string> whose value is attr value.
// NOTE: No parsing or modification of any kind is performed on the value.
if (syntax.visit(
[](Empty) { return true; },
[](RawString) { return true; },
[](RawStringKeyword) { return true; },
[](auto&) { return false; })) {
return { Token::create_string(*attribute_value) };
}
// 5. Substitute arbitrary substitution functions in attr value, with «"attribute", attr name» as the substitution
// 6. Substitute arbitrary substitution functions in attr value, with «"attribute", attr name» as the substitution
// context, then parse with a <syntax> attr value, with syntax and el. If that succeeds, return the result;
// otherwise, jump to the last step (labeled FAILURE).
auto parser = Parser::create(ParsingParams { element.element().document() }, attribute_value.value());
@@ -178,28 +236,10 @@ static Vector<ComponentValue> replace_an_attr_function(DOM::AbstractElement& ele
auto parsed_value = parse_with_a_syntax(ParsingParams { element.document() }, substituted_values, *syntax.get<NonnullOwnPtr<SyntaxNode>>(), element);
if (parsed_value->is_guaranteed_invalid())
return failure();
if (unit_name.has_value()) {
// https://drafts.csswg.org/css-values-5/#ref-for-typedef-attr-type%E2%91%A0
// If given as an <attr-unit> value, the value is first parsed as if number keyword was specified, then the
// resulting numeric value is turned into a dimension with the corresponding unit, or a percentage if % was
// given. Same as for number <attr-type>, values that do not correspond to the <number-token> production
// trigger fallback.
// FIXME: The spec is ambiguous about what we should do for non-number-literals.
// Chromium treats them as invalid, so copy that for now.
// Spec issue: https://github.com/w3c/csswg-drafts/issues/12479
if (!parsed_value->is_number())
return failure();
if (unit_name == "%"_fly_string)
return { Token::create_percentage(Number { Number::Type::Number, parsed_value->as_number().number() }) };
return { Token::create_dimension(parsed_value->as_number().number(), unit_name.release_value()) };
}
return parsed_value->tokenize();
// 6. FAILURE:
// NB: Step 6 is a lambda defined at the top of the function.
// 7. FAILURE:
// NB: Step 7 is a lambda defined at the top of the function.
}
// https://drafts.csswg.org/css-env/#substitute-an-env