295854 2025-07-13 01:45:08 -0700 [WebIDL] Add WebIDL support for [Enumerated] extended attribute, and related attributes: [MissingValueDefault], [InvalidValueDefault] 2025-08-02 15:00:12 -0700 1 1 1 Unclassified WebKit Bindings Other Unspecified Unspecified RESOLVED FIXED InRadar P2 Normal --- 1 rahim_abdi webkit-unassigned cdumez webkit-bug-importer oldest_to_newest 2129673 0 rahim_abdi 2025-07-13 01:45:08 -0700 In .idl files, it would be helpful to simplify defining enumerated attributes to streamline getter/setter code generation (and not have to code these manually). This is particularly useful for enumerated attributes since they are limited to known values, and have two optional, special states: missing value default and invalid value default; all of these could be specified as part of an attribute's .idl declaration. For example (ignoring that these may not be truly valid values): CURRENT: [CEReactions=Needed, Reflect=aria_orientation] attribute DOMString? ariaOrientation; PROPOSED: [CEReactions=Needed, Reflect=aria_orientation, ReflectOnly=("horizontal", "vertical", "undefined"), ReflectMissing=("vertical"), ReflectInvalid=("horizontal")] attribute DOMString? ariaOrientation; Per HTML spec, DOMString and nullable DOMString (DOMString?) do not require that the attribute be enumerated however, where a content attribute is enumerated, it must be limited to known values; see DOMString and DOMString reflection algorithm: https://html.spec.whatwg.org/#reflecting-content-attributes-in-idl-attributes. Note: These new extended attributes are not defined in WebIDL, although they are described in WebIDL spec prose. Also, Chrome already supports them: https://chromium.googlesource.com/chromium/src/+/HEAD/third_party/blink/renderer/bindings/IDLExtendedAttributes.md#reflectonly. 2129674 1 rahim_abdi 2025-07-13 01:57:25 -0700 Pull request: https://github.com/WebKit/WebKit/pull/47953 2131456 2 webkit-bug-importer 2025-07-20 01:46:12 -0700 <rdar://problem/156249490> 2131511 3 rahim_abdi 2025-07-20 19:20:57 -0700 New approach from PR comment on improving syntax of enumerated attributes using 'enum' IDL type: https://github.com/WebKit/WebKit/pull/47953#pullrequestreview-3014249574. To better support .idl definition of reflected DOMString/DOMString? attributes, the following should be added: - [Enumerated] = allowed on attributes that use [Reflect] and used to specify two or more known values for the attribute - [MissingValueDefault] = the value of the IDL attribute when the content attribute is missing: https://html.spec.whatwg.org/#missing-value-default - [InvalidValueDefault] = the value of the IDL attribute when the content attribute has a non-permitted value: https://html.spec.whatwg.org/#invalid-value-default - [EmptyValueDefault] = the value of the IDL attribute when the content attribute is present without a value, e.g., <div someAttr> (as opposed to <div someAttr="foo"> For example: [ MissingValueDefault=“Value1”, InvalidValueDefault=“Value3”, ] enum attrnameAttribute { "Value1", "Value2", "Value3" } … [Reflect=myattr, Enumerated=attrnameAttribute] attribute DOMString? myattr; 2134051 4 ews-feeder 2025-08-02 15:00:09 -0700 Committed 298172@main (5c150f7a3b58): <https://commits.webkit.org/298172@main> Reviewed commits have been landed. Closing PR #47953 and removing active labels.