This repository contains machine-readable references of CSS properties, definitions, IDL, and other useful terms that can be automatically extracted from web browser specifications (see a list of projects known to use the data). The contents of the repository are updated automatically every 6 hours (although note information about published /TR/ versions of specifications are updated only once per day).
Specifications covered by this repository are technical Web specifications that appear in browser-specs.
The main
branch of this repository contains automatically-generated raw extracts from web browser specifications. These extracts come with no guarantee on validity or consistency. For instance, if a specification defines invalid IDL snippets or uses an unknown IDL type, the corresponding IDL extract in this repository will be invalid as well.
The curated
branch contains curated extracts. Curated extracts are generated from raw extracts in the ed
folder by applying manually-maintained patches to fix invalid content and provide validity and consistency guarantees. The curated
branch is updated automatically whenever the main
branch is updated, unless patches need to be modified (which requires manual intervention). Curated extracts are published under https://w3c.github.io/webref/ed/.
Additionally, subsets of the curated content get manually reviewed and published as NPM packages on a weekly basis:
@webref/idl
contains a curated version of theed/idl
folder.@webref/css
contains a curated version of theed/css
folder.@webref/elements
contains a curated version of theed/elements
folder.@webref/events
contains a curated version of theed/events
folder.
Important: The curated extracts only contain data for specifications that are in good standing (to keep the number of manually-maintained patches minimal and manageable). The NPM packages only contain curated extracts of specifications that are in good standing and that target web browsers.
Important: Unless you are ready to deal with invalid content, we strongly recommend that you process contents of the curated
branch or NPM packages instead of raw content in the main
branch.
This repository contains raw and curated information about nightly versions of Web specifications in the ed
folder, as well as raw information about the released version (for /TR/ specifications) in the tr
folder.
Note: The tr
folder only contains information about released specifications. Specifications that have not been published as /TR/ documents (such as WHATWG specifications or Community Group reports) do not appear under the tr
folder in particular.
More often than not, released versions of specifications are much older than their nightly version. Data in the tr
folder is more invalid/inconsistent than data in the ed
folder as a result. Additionally, no attempt is being made at curating data in the tr
folder, use the tr
folder at your own risk!
The following subfolders in the curated
branch contain individual machine-readable JSON or text files generated from specifications:
ed/css
: CSS terms (properties, descriptors, value spaces). One file per specification series.ed/dfns
:<dfn>
terms, along with metadata such as linking text, access level, namespace. One file per specification.ed/elements
: Markup elements defined, along with the interface that they implement. One file per specification.ed/headings
: Section headings. One file per specification.ed/idl
: Raw WebIDL index. One file per specification series.ed/idlnames
: WebIDL definitions per referenceable IDL name. One file per IDL name.ed/idlnamesparsed
: Parsed WebIDL structure of definitions in theidlnames
folder. One file per IDL name.ed/idlparsed
: Parsed WebIDL structure of definitions in theidl
folder. One file per specification.ed/ids
: Fragments defined in the specification. One file per specification.ed/links
: Links to other documents, along with targeted fragments. One file per specification.ed/refs
: Normative and informative references to other specifications. One file per specification.
Individual files are named after the shortname of the specification, or after the shortname of the specification series for CSS definitions and raw IDL files. Individual files are only created when needed, meaning when the specification actually includes relevant terms.
The ed/index.json
file contains the index of specifications that have been crawled, and relative links to individual files that have been created.
This repository uses Reffy, a Web spec exploration tool, to crawl the specifications and generate the data. In particular, the data it contains is the result of running Reffy. The repository does not contain any more data.
Raw WebIDL extracts are used in web-platform-tests, please see their interfaces/README.md for details.
Data curation brings the following guarantees.
- All IDL files can be parsed by the version of webidl2.js referenced in
package.json
. WebIDL2.validate
passes with the exception of the "no-nointerfaceobject" rule about[LegacyNoInterfaceObject]
, which is in wide use.- All types are defined by some specification.
- All extended attributes are defined by some specification.
- No duplicate top-level definitions or members.
- No missing or mismatched types in inheritance chains.
- No conflicts when applying mixins and partials.
- All values in CSS files can be parsed by the version of CSSTree used in
peerDependencies
inpackage.json
. - No duplicate definitions of CSS properties provided that CSS extracts of delta specs are not taken into account (such extracts end with
-n.json
, wheren
is a level number). - CSS extracts contain a base definition of all CSS properties that get extended by other CSS property definitions (those for which
newValues
is set). - All entries in CSS files that do not extend a base definition link back to their actual definition in the spec. In other words, all entries under
properties[]
,properties[].values[]
,selectors[]
,atrules[]
andvalues[]
have anhref
key that contains an absolute URL with fragment, except properties that that have anewValues
key, at-rules that neither have aprose
nor avalue
key, and definitions of a delta spec that completely override a definition in a previous level.
- All Web IDL interfaces referenced by elements exist in Web IDL extracts.
- All elements link back to their definition in the spec.
- All events have a
type
attribute that match the name of the event - All events have a
interface
attribute to describe the interface used by the Event. The Web IDL interface exists in the latest version of the@webref/idl
package at the time the@webref/events
package is released, and represents an actual interface (i.e. not a mixin). - All events have a
targets
attribute with a non-empty list of target interfaces on which the event may fire. All Web IDL interfaces in the list exist in the latest version of the@webref/idl
package at the time the@webref/events
package is released, and represent an actual interface (i.e. not a mixin). - The
bubbles
attribute is always set to a boolean value for target interfaces that belong to a bubbling tree (DOM, IndexedDB, Serial API, Web Bluetooth). - The
bubbles
attribute is only set for target interfaces that belong to a bubbling tree. - The
bubblingPath
attribute is only set for target interfaces on which the event bubbles. - The
targets
attribute contains the top most interfaces in an inheritance chain, unless bubbling conditions differ. For instance, the list may contain{ "target": "Element", "bubbles": true }
but not also{ "target": "HTMLElement", "bubbles": true }
sinceHTMLElement
inherits fromElement
. - For target interfaces that belong to a bubbling tree, the
targets
attribute only contains the deepest interface in the bubbling tree on which the event may fire and bubble. For instance, the list may contain{ "target": "HTMLElement", "bubbles": true }
, but not also{ "target": "Document" }
since event would de facto fire atDocument
through bubbling.
The following projects are known to use webref data:
- MDN content management system, yari
- Web Platform Tests
- Open Web Docs MDN Browser Compat Data collector
- bikeshed, a specification authoring tool
- ReSpec, a specification authoring tool
- "DOM" Bindings for TypeScript
- browser API bindings for Dart
- the Pulsar text editor
- PostCSS preset env plugin
- strudy
- nodysseus
- WebIDLPedia
- Webdex
Using webref data in a project that is not yet in the list? Let us know!
Webref extracts are analyzed with Strudy to detect potential spec content anomalies such as broken links or invalid constructs, and report them as issues in the repository that hosts the spec.
Global analyses used to be published in the w3c/webref-analysis repository. That repository was archived in August 2024.
Feel free to raise issues in this repository as needed. Note that most issues likely more directly apply to underlying tools:
- Errors in the data are most likely caused by bugs or missing features in Reffy, which is the tool that crawls and parses specifications under the hoods. If you spot an error, please report it in Reffy's issue tracker.
- If you believe that a spec is missing from the list, please check browser-specs and report it there.
GitHub Actions workflows are used to automate most of the tasks in this repo.
- Update ED report - crawls the nightly version of specifications and updates the contents of the
ed
folder. Workflow runs every 6 hours. Specifications that have not been modified since last crawl are skipped, unless the version of Reffy changed in the meantime. A typical crawl takes a few minutes to complete. A full crawl takes up to 12mn. - Update TR report - crawls the released version of specifications and updates the contents of the
tr
folder. Workflow runs once per day. A typical crawl takes a few minutes to complete. A full crawl takes up to 8mn. - Curate data & Prepare package PRs - runs whenever crawled data gets updated and updates the
curated
branch accordingly (provided all tests pass). The job also creates pull requests to release new versions of NPM packages when needed. Each pull request details the diff that would be released, and bumps the package version in the relevantpackages/xxx/package.json
file. - Clean up abandoned files - checks the contents of repository to detect orphan crawl files that are no longer targeted by the latest crawl's result and creates a PR to delete these files from the repository. Runs once per week on Wednesday. The crawl workflows does not delete these files automatically because crawl sometimes fails on a spec due to transient network or spec errors.
- Test - runs tests on pull requests.
- Clean patches when issues/PR are closed - drops patches that no longer need to apply because underlying issues got fixed. Runs once per week.
- Publish
@webref/xx
package if needed - publishes a new version of the@webref/css
,@webref/elements
,@webref/events
or@webref/idl
package to NPM, tags the corresponding commits on themain
andcurated
branches, and updates the relevant@webref/xxx@latest
tag to point to the right commit on thecurated
branch. Runs whenever a pre-release PR is merged. Note that the released version is the version that appeared inpackages/css/package.json
,packages/elements/package.json
,packages/events/package.json
orpackages/idl/package.json
before the pre-release PR is merged. @webref/xx
release: Request review of pre-release PR - assigns reviewers to NPM package pull requests. Runs once per week.