Hi Mason, Thanks for continuing to work to get interoperable support for declarative shadow DOM!
On Thu, Jan 19, 2023 at 7:36 PM Mason Freed <mas...@chromium.org> wrote: > Contact emailsmas...@chromium.org > > Explainerhttps://github.com/whatwg/html/pull/5465 > https://github.com/whatwg/dom/pull/892 > > Specificationhttps://github.com/whatwg/html/pull/5465 > > Summary > > Chromium has shipped [1] a version of declarative shadow DOM in M90 which > currently has 0.014% usage [2]. Mostly, the low usage is due to the spec PR > being stalled with no input from other implementers. Recently, there has > been renewed interest in the feature, and discussions have resumed. As part > of those discussions, two changes have been generally agreed upon: 1. > Rename the `<template>` attribute from `shadowroot` to `shadowrootmode`. 2. > Support streaming, by attaching the shadow root on the opening, rather than > the closing, template tag. While the PR hasn't landed, and there is still > an open issue (related to the DOMParser), we would like to ship the agreed > upon behavior listed above. WebKit has already enabled this behavior by > default > <https://github.com/WebKit/WebKit/commit/e7d5dde467956b24438d23f458d4d527f7fd108d>. > [1] https://chromestatus.com/feature/5191745052606464 [2] > https://chromestatus.com/metrics/feature/timeline/popularity/3196 > > > Blink componentBlink>DOM>ShadowDOM > <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EDOM%3EShadowDOM> > > Search tagsdeclarative > <https://chromestatus.com/features#tags:declarative>, shadow > <https://chromestatus.com/features#tags:shadow> > > TAG review > TAG review statusNot applicable > > Risks > > > Interoperability and Compatibility > > The new version of declarative shadow DOM has observable differences in > behavior: streaming. The launch plan is to ship the new behavior via the > new attribute name (`shadowrootmode`), while preserving the old behavior > under the old attribute name (`shadowroot`). Once the new behavior is > landed and stabilized, we will make a plan to deprecate the old shadowroot > attribute and behavior. This should ensure that the compat risk is low as > we transition to the new behavior. > > > *Gecko*: Positive ( > https://github.com/whatwg/html/pull/5465#pullrequestreview-1132523065) > Per our process, Mozilla has asked that we only consider positive signals from their standards-position repo. I see they currently have <https://mozilla.github.io/standards-positions/#declarative-shadow-dom> a 'neutral' for declarative shadow DOM with concerns about the cost/benefit tradeoff of the feature. Also this is a link to a comment by a (now) Apple employee. Did you have a different link in mind perhaps? *WebKit*: Positive ( > https://github.com/whatwg/html/pull/5465#pullrequestreview-1132523065) > Based on your link <https://github.com/WebKit/WebKit/commit/e7d5dde467956b24438d23f458d4d527f7fd108d> above we can now call this "shipping", right? That's a very strong signal IMHO. *Web developers*: Positive (https://github.com/whatwg/dom/issues/831) > Search "streaming" on the issue discussion and you'll find many supportive > comments. > > *Other signals*: > > Ergonomics > > No difference from existing, shipped declarative shadow DOM implementation. > > > Activation > > No difference from existing, shipped declarative shadow DOM implementation. > > > Security > > No difference from existing, shipped declarative shadow DOM implementation. > > > 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? > > > > Debuggability > > No difference from existing, shipped declarative shadow DOM implementation. > > > Will this feature be supported on all six Blink platforms (Windows, Mac, > Linux, Chrome OS, 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 > I see the test link <https://wpt.fyi/results/shadow-dom/declarative?label=master&label=experimental&aligned&view=subtest>, but are tests written somewhere for this change in particular? In particular do latest WebKit and chromium with this flag enabled pass the exact same set of tests for declarative shadow DOM or are there still notable behavior differences? Flag nameStreamingDeclarativeShadowDOM > > Requires code in //chrome?False > > Tracking bughttps://crbug.com/1379513 > > Estimated milestones > > M111 > > > 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). > > > Link to entry on the Chrome Platform Status > https://chromestatus.com/feature/5161240576393216 > > 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 blink-dev+unsubscr...@chromium.org. > To view this discussion on the web visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAM%3DNeDhGHqD6du83UKvRpX-P7ftaG_R8j1pXE-ofqwHGf-sysA%40mail.gmail.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAM%3DNeDhGHqD6du83UKvRpX-P7ftaG_R8j1pXE-ofqwHGf-sysA%40mail.gmail.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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