On Wed, Aug 9, 2023 at 6:44 PM Fergal Daly <fer...@google.com> wrote:
> On Wed, 9 Aug 2023 at 12:01, Domenic Denicola <dome...@chromium.org> > wrote: > >> I think specifying these reasons is important. As noted in the linked >> issue <https://github.com/WICG/bfcache-not-restored-reason/issues/2>, I >> think the end goal should be: >> >> - Every reason that a browser ever emits, is found in a specification >> somewhere. (It doesn't have to be the HTML spec, e.g. the speech synthesis >> reason could live in the speech synthesis spec.) >> >> There's no intrinsic reason for speech synthesis to block BFCache. It > just happens that Chrome blocked it. There's no spec reason for unload to > block BFCache, in fact the spec says that it doesn't. > > I think it's good for us to have agreed names, e.g. > "unload-event-handler". Should we put into various specs "if an implementer > chooses to block BFCache because X has been used, they should use the > reason `Y`"? > > >> - If browsers prevent bfcache restoration for a reason not found in a >> spec, it is always translated to a standardized reason such as "unknown". >> >> This avoids the usual interop problems with vendor-specific extensions to >> the web platform, such as: no clear specification for what strings to use; >> no clear point at which the reason is added to the document's reasons list; >> etc. Although you claim these reasons are idiosyncratic to Chrome, that >> won't necessarily be the case; e.g. Firefox has unload handler as a reason, >> and I suspect most user agents have memory limitations or similar. >> > > Chrome has over 100 reasons. I'd say at least 50 of them are actionable > such that you wouldn't want to lump them into an opaque "unknown" category. > > I do not relish the idea of updating 50 places in spec to insert a name to > be used if you decide to block. > > How about maintaining a central list of reasons with low friction to add > new reasons even if they are browser-specific? The cases where you *must* > block > should still be inline in spec (and also on the list), > That sounds great to me. We should probably make this separation clear in the spec, e.g. the "must" list will have cross-references you can follow, whereas the "may" list ends up only being cross-referenced from some generic location like https://html.spec.whatwg.org/multipage/browsing-the-web.html#note-bfcache:~:text=User%20agents%20may,keeping%20it%20cached. . > > F > > >> >> We could have a discussion about allowing vendor-specific information in >> the API *in addition* to the standardized reasons. For example, we could >> have one of the standardized reasons be "user-agent-specific", and then add >> an additional field userAgentSpecificInfo. But I would like to see >> significantly more discussion with other vendors before going that route. >> >> On Tue, Aug 8, 2023 at 9:56 PM Yuzu Saijo <yu...@google.com> wrote: >> >>> +bfcache-dev >>> >>> I was talking to Fergal today and discussed this, and I am not sure >>> about adding browser-specific reasons to the spec. >>> For example, some reasons like "speech synthesis API is used" / "unload >>> handler" are completely specific to Chrome, and it doesn't really make >>> sense to add them to the spec, even with the namespace (x-speechsysthesis / >>> x-unloadhandler). >>> Maybe we can document the reasons somewhere in a shared list but not in >>> the spec? >>> >>> I think the API would be more useful if it can give as much information >>> as possible, not limited to the specced reasons. >>> Please let me know what you think! >>> >>> Yuzu >>> >>> >>> On Thursday, August 3, 2023 at 12:39:17 PM UTC+9 Yuzu Saijo wrote: >>> >>>> Sorry for the delayed response. >>>> >>>> *> there doesn't appear to be any NotRestoredReasons interface defined >>>> in Chromium?* >>>> Let me address this implementation and delay the shipping until the >>>> chromium implementation matches the proposed spec. Thanks for pointing it >>>> out! >>>> Same for WPT. I will add tests for all the standardized reasons. >>>> >>>> *> Can you confirm that you're only shipping the specified four?* >>>> We do have ~50 not restored reasons, and in theory we will be able to >>>> remove most of them except for the standardized four reasons. >>>> However, in reality it will take time for us to support all the reasons >>>> and we need to keep blocking on them for a while. >>>> In the meantime, our plan was to expose the non-standardized reasons >>>> too, but in a way that's distinguishable from standardized reasons as >>>> you suggested here >>>> <https://github.com/WICG/bfcache-not-restored-reason/issues/2>. >>>> I realized that we need to add browser specific reasons to the spec as >>>> well. Let me add that and send a review request again. >>>> >>>> Thanks! >>>> Yuzu >>>> On Thursday, July 13, 2023 at 12:07:05 PM UTC+9 dom...@chromium.org >>>> wrote: >>>> >>>>> Also, checking the tests, it seems like the currently-implemented >>>>> reasons don't match the spec. E.g. this test >>>>> <https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/web_tests/external/wpt/performance-timeline/not-restored-reasons/performance-navigation-timing-bfcache-reasons-stay.tentative.window.js> >>>>> requires >>>>> the reason to be "WebSocket", but the specification says "websocket" >>>>> (lowercase). I couldn't find tests for the other three reasons... >>>>> >>>>> On Thu, Jul 13, 2023 at 12:04 PM Domenic Denicola <dom...@chromium.org> >>>>> wrote: >>>>> >>>>>> I have some questions about how well the implementation here matches >>>>>> up with the spec. >>>>>> >>>>>> First, there doesn't appear to be any NotRestoredReasons interface >>>>>> defined in Chromium? The relevant attribute on >>>>>> PerformanceNavigationTiming returns object? >>>>>> <https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/timing/performance_navigation_timing.idl;l=33?q=NotRestoredReasons%20file:%5C.idl&ss=chromium>. >>>>>> That seems like a problematic mismatch... >>>>>> >>>>>> Second, I can't find exactly where the list of script-exposed not >>>>>> restored reasons are. But, I'll note that Chromium seems to have ~50 >>>>>> such reasons >>>>>> <https://source.chromium.org/chromium/chromium/src/+/refs/heads/main:content/browser/renderer_host/back_forward_cache_metrics.h;drc=6754d1409bf5099314eea7e87e896622ade9bc0f;l=49>, >>>>>> whereas you've only specified 4 (fetch, navigation-failure, >>>>>> parser-aborted, >>>>>> websocket). Can you confirm that you're only shipping the specified four? >>>>>> >>>>>> Thanks! >>>>>> >>>>>> On Thu, Jul 13, 2023 at 12:11 AM Yoav Weiss <yoav...@chromium.org> >>>>>> wrote: >>>>>> >>>>>>> >>>>>>> >>>>>>> On Thu, Jul 6, 2023 at 7:28 AM 'Yuzu Saijo' via blink-dev < >>>>>>> blin...@chromium.org> wrote: >>>>>>> >>>>>>>> Contact emails >>>>>>>> >>>>>>>> yu...@google.com, yu...@chromium.org, fer...@chromium.org >>>>>>>> >>>>>>>> Explainer >>>>>>>> >>>>>>>> >>>>>>>> https://github.com/WICG/bfcache-not-restored-reason/blob/main/NotRestoredReason.md >>>>>>>> >>>>>>>> Specification >>>>>>>> >>>>>>>> https://github.com/whatwg/html/pull/9360 >>>>>>>> >>>>>>>> Design docs >>>>>>>> >>>>>>>> >>>>>>>> https://github.com/WICG/bfcache-not-restored-reason/blob/main/NotRestoredReason.md >>>>>>>> >>>>>>>> Summary >>>>>>>> >>>>>>>> NotRestoredReason API will report the list of reasons why a page is >>>>>>>> not served from BFcache in a frame tree structure, via >>>>>>>> PerformanceNavigationTiming API. >>>>>>>> >>>>>>>> >>>>>>>> Blink component >>>>>>>> >>>>>>>> UI>Browser>Navigation>BFCache >>>>>>>> <https://bugs.chromium.org/p/chromium/issues/list?q=component:UI%3EBrowser%3ENavigation%3EBFCache> >>>>>>>> >>>>>>>> TAG review >>>>>>>> >>>>>>>> https://github.com/w3ctag/design-reviews/issues/739 >>>>>>>> >>>>>>>> TAG review status >>>>>>>> >>>>>>>> Issues addressed >>>>>>>> >>>>>>>> Risks >>>>>>>> >>>>>>>> Interoperability and Compatibility >>>>>>>> >>>>>>>> Gecko: Defer ( >>>>>>>> https://github.com/mozilla/standards-positions/issues/766) Once >>>>>>>> issues (standardized reasons & unsalvageable documents), they would >>>>>>>> switch >>>>>>>> to positive. >>>>>>>> >>>>>>> >>>>>>> It seems like the "standardized reasons" part is addressed in your >>>>>>> PR. Is the same true for the second point? >>>>>>> >>>>>>> >>>>>>>> >>>>>>>> WebKit: No signal ( >>>>>>>> https://github.com/WebKit/standards-positions/issues/154) >>>>>>>> >>>>>>>> Web developers: Positive ( >>>>>>>> https://github.com/w3c/navigation-timing/issues/171#issuecomment-1062672989 >>>>>>>> ) >>>>>>>> >>>>>>>> Other signals: Positive from Origin Trial users: >>>>>>>> >>>>>>>> How likely are you to keep using this feature? >>>>>>>> >>>>>>>> 92% answered likely, 8% (1 vote) is unsure >>>>>>>> >>>>>>>> Security >>>>>>>> >>>>>>>> We do not report detailed information about cross-origin iframes. >>>>>>>> See Security and Privacy section >>>>>>>> <https://github.com/WICG/bfcache-not-restored-reason/blob/main/NotRestoredReason.md#security-and-privacy> >>>>>>>> in the explainer. >>>>>>>> >>>>>>>> >>>>>>>> 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? >>>>>>>> >>>>>>>> No. >>>>>>>> >>>>>>>> >>>>>>>> Debuggability >>>>>>>> >>>>>>>> In DevTools console, try: >>>>>>>> >>>>>>>> performance.getEntriesByType('navigation')[0].notRestoredReasons; >>>>>>>> >>>>>>>> >>>>>>>> Will this feature be supported on all six Blink platforms (Windows, >>>>>>>> Mac, Linux, Chrome OS, Android, and Android WebView)? >>>>>>>> >>>>>>>> Yes. >>>>>>>> >>>>>>>> NotRestoredReasons API is available on all platforms including >>>>>>>> WebView, but back/forward cache is not enabled on WebView. So on >>>>>>>> WebView, >>>>>>>> NotRestoredReasons API should always say that the page is blocked from >>>>>>>> being restored from bfcache with the reason being something like “not >>>>>>>> supported”. >>>>>>>> >>>>>>>> (Currently it reports null due to a bug >>>>>>>> <https://bugs.chromium.org/p/chromium/issues/detail?id=1459533>) >>>>>>>> >>>>>>>> Is this feature fully tested by web-platform-tests >>>>>>>> <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md> >>>>>>>> ? >>>>>>>> >>>>>>>> Yes. >>>>>>>> https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/web_tests/external/wpt/performance-timeline/not-restored-reasons/ >>>>>>>> >>>>>>>> DevTrial instructions >>>>>>>> >>>>>>>> >>>>>>>> https://github.com/rubberyuzu/bfcache-not-retored-reason/blob/main/HowToTest.md >>>>>>>> >>>>>>>> Flag nameblink RunTimeEnabledFeature: >>>>>>>> BackForwardCacheSendNotRestoredReasons >>>>>>>> <https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/platform/runtime_enabled_features.json5;l=423?q=BackForwardCacheSendNotRestoredReasons%20-f:out&ss=chromium> >>>>>>>> Requires code in //chrome? >>>>>>>> >>>>>>>> False >>>>>>>> >>>>>>>> Tracking bug >>>>>>>> >>>>>>>> https://bugs.chromium.org/p/chromium/issues/detail?id=1326344 >>>>>>>> >>>>>>>> Launch bug >>>>>>>> >>>>>>>> https://launch.corp.google.com/launch/4200848 >>>>>>>> >>>>>>>> Estimated milestones >>>>>>>> >>>>>>>> Shipping on desktop >>>>>>>> >>>>>>>> 116 >>>>>>>> >>>>>>>> OriginTrial desktop last >>>>>>>> >>>>>>>> 114 >>>>>>>> >>>>>>>> OriginTrial desktop first >>>>>>>> >>>>>>>> 109 >>>>>>>> >>>>>>>> DevTrial on desktop >>>>>>>> >>>>>>>> 108 >>>>>>>> >>>>>>>> Shipping on Android >>>>>>>> >>>>>>>> 116 >>>>>>>> >>>>>>>> OriginTrial Android last >>>>>>>> >>>>>>>> 114 >>>>>>>> >>>>>>>> OriginTrial Android first >>>>>>>> >>>>>>>> 109 >>>>>>>> >>>>>>>> DevTrial on Android >>>>>>>> >>>>>>>> 108 >>>>>>>> >>>>>>>> >>>>>>>> Shipping on WebView >>>>>>>> >>>>>>>> 116 >>>>>>>> >>>>>>>> OriginTrial WebView last >>>>>>>> >>>>>>>> 114 >>>>>>>> >>>>>>>> OriginTrial WebView first >>>>>>>> >>>>>>>> 109 >>>>>>>> >>>>>>>> DevTrial on WebView >>>>>>>> >>>>>>>> 108 >>>>>>>> >>>>>>>> >>>>>>>> Anticipated spec changes >>>>>>>> >>>>>>>> Open questions about a feature may be a source of future web compat >>>>>>>> or interop issues. Please list open issues. >>>>>>>> >>>>>>>> https://github.com/whatwg/html/pull/9360 >>>>>>>> >>>>>>>> >>>>>>>> Link to entry on the Chrome Platform Status >>>>>>>> >>>>>>>> https://chromestatus.com/feature/5684908759449600 >>>>>>>> >>>>>>>> Links to previous Intent discussions >>>>>>>> >>>>>>>> Intent to prototype: >>>>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAP-nMoGAzjUjzv3WmxcRpUSBgnA-AHQ05kh9gXc%2BQB8pRM6%2BfA%40mail.gmail.com >>>>>>>> Intent to Experiment: >>>>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAP-nMoHe391sAB2PdbEVw9uiSPFxTB_EYsRizcPpZ7-pg16O0A%40mail.gmail.com >>>>>>>> >>>>>>>> Intent to Extend Experiment: >>>>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAA5e698QcKZSthm%3Dz_4pi8cOzi4kfbx-AXveC%2BAKimUh-tMycA%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 blink-dev+...@chromium.org. >>>>>>>> To view this discussion on the web visit >>>>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAP-nMoHYpT3sxWV%2BEipL5NcNSWy8fOdDdAroucmNb%3DZvxJWRBA%40mail.gmail.com >>>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAP-nMoHYpT3sxWV%2BEipL5NcNSWy8fOdDdAroucmNb%3DZvxJWRBA%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>>>>> . >>>>>>>> >>>>>>> -- >>>>>>> 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+...@chromium.org. >>>>>>> To view this discussion on the web visit >>>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAL5BFfXtkH6O82W%2BWm9ckCyYasSJt2cbs9VA4VZAmYhtivgj4g%40mail.gmail.com >>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAL5BFfXtkH6O82W%2BWm9ckCyYasSJt2cbs9VA4VZAmYhtivgj4g%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>>>> . >>>>>>> >>>>>> -- >> You received this message because you are subscribed to the Google Groups >> "bfcache-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to bfcache-dev+unsubscr...@chromium.org. >> To view this discussion on the web, visit >> https://groups.google.com/a/chromium.org/d/msgid/bfcache-dev/CAM0wra-P3NxELP28%3Dgh%3D3ROC35m8ijS_5RRcStyjFew1AXNyEg%40mail.gmail.com >> <https://groups.google.com/a/chromium.org/d/msgid/bfcache-dev/CAM0wra-P3NxELP28%3Dgh%3D3ROC35m8ijS_5RRcStyjFew1AXNyEg%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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