I'm very happy to see this, looks great! We're slowly getting the web to a place where we have real component modularity :-)
I have one question about debuggability below, but since that bit has already been approved in Chromestatus it's not blocking. LGTM1 On Mon, Oct 13, 2025 at 5:00 PM Chromestatus < [email protected]> wrote: > *Contact emails* > [email protected], [email protected], [email protected] > > *Explainer* > > https://github.com/WICG/webcomponents/blob/gh-pages/proposals/Scoped-Custom-Element-Registries.md > https://github.com/whatwg/html/issues/10854 > > *Specification* > > https://html.spec.whatwg.org/multipage/custom-elements.html#customelementregistry > > *Summary* > This feature allows for multiple custom element definitions for a single > tag name to exist within a page to prevent custom element name conflicts > when a web app uses libraries from multiple sources. This is achieved by > allowing user code to create multiple custom element registries and > associate them with tree scopes and elements that function as scoping > object for custom element creation/definition/upgrade. > > *Blink component* > Blink>HTML>CustomElements > <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EHTML%3ECustomElements%22> > > *Web Feature ID* > scoped-custom-element-registries > <https://webstatus.dev/features/scoped-custom-element-registries> > > *TAG review* > https://github.com/w3ctag/design-reviews/issues/1070 > > *TAG review status* > Issues addressed > > *Risks* > > > *Interoperability and Compatibility* > None > > *Gecko*: Positive ( > https://github.com/mozilla/standards-positions/issues/424) > > *WebKit*: Shipped/Shipping ( > https://developer.apple.com/documentation/safari-release-notes/safari-26-release-notes > ) > > *Web developers*: Positive Scoped custom element registry has been a > long-awaited feature from the Web Components Community Group, and the > current polyfill that didn't solve the entire problem has 24k+ downloads > per week. > > *Other signals*: > > *WebView application risks* > > Does this intent deprecate or change behavior of existing APIs, such that > it has potentially high risk for Android WebView-based applications? > None > > > *Debuggability* > None Are you sure? If I'm trying to debug a web page and trying to understand the behavior of <my-foo> elements, might I now get confused due to the multiple definitions for the same element name? I played with this a little and I guess I can always just rely on commands like $0.constructor to find the relevant source. But Firefox has a UI badge and hover action for this: [image: image.png] Perhaps the scoped custom element registry makes a UI feature like this go from nice-to-have to essential? @Danil Somsikov <[email protected]> for his thoughts since he reviewed and approved the Debuggability bit for this feature. > *Will this feature be supported on all six Blink platforms (Windows, Mac, > Linux, ChromeOS, Android, and Android WebView)?* > Yes > > *Is this feature fully tested by web-platform-tests > <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?* > Yes > > https://wpt.fyi/results/custom-elements/registries?label=master&label=experimental&aligned > > *Flag name on about://flags* > None > > *Finch feature name* > ScopedCustomElementRegistry > > *Rollout plan* > Will ship enabled for all users > > *Requires code in //chrome?* > False > > *Tracking bug* > https://issues.chromium.org/issues/40826514 > > *Estimated milestones* > Shipping on desktop 143 > Shipping on Android 143 > Shipping on WebView 143 > > *Anticipated spec changes* > > Open questions about a feature may be a source of future web compat or > interop issues. Please list open issues (e.g. links to known github issues > in the project for the feature specification) whose resolution may > introduce web compat/interop risk (e.g., changing to naming or structure of > the API in a non-backward-compatible way). > None > > *Link to entry on the Chrome Platform Status* > https://chromestatus.com/feature/5090435261792256?gate=6499099686207488 > > *Links to previous Intent discussions* > Intent to Prototype: > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAFqEGhaAi0t1ffJoE8Du9bB2Wwxt6CewJjxz2Y_m9qWuoAa-Ug%40mail.gmail.com > > > This intent message was generated by Chrome Platform Status > <https://chromestatus.com>. > > -- > You received this message because you are subscribed to the Google Groups > "blink-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/68ed6866.050a0220.2a8282.0159.GAE%40google.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/68ed6866.050a0220.2a8282.0159.GAE%40google.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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