Hi Yoav&Alex, thanks for the feedback. I'll make it more clear. Generally speaking, the final goal is that, we want to avoid queuing a task to dispatch a selectionchange event when there is already a task scheduled to do that. This is to catch up the latest spec: https://w3c.github.io/selection-api/#scheduling-selectionhange-event. Currently we divide this into 2 steps with one CL for each step to impelment this goal.
In this issue, we'd like to land *the first CL* that updates the implementation of selectionchange event to be fired on input element and textarea element instead of document. So the difference in the first CL is: 1. The old behaviour: When the element(input/textarea) provides a text selectionchange or its selection changes, we dispatch a selectionchange event on the document directly. 2. The new behaviour: The new codes goes to that, in the same situations, if the selection changes, we fire this event first on the element(input/textarea) itself, and then it would be bubbled to the doument. So, the final results are the same that, we finally get a selectionchange event on the document. *The feature in this issue* is mainly to do this change. After the first CL is landed, then we come to the second CL. The main change of the behaviour would be in the second CL. In *the second CL*, we will change the behaviour: 1. The old behaviour: When the element(input/textarea) provides a text selectionchange or its selection changes, we dispatch a selectionchange event on the element. We don't care whether this event is executed, and we just dipatch it. 2. The new behaviour: Now based on the new spec(https://w3c.github.io/selection-api/#scheduling-selectionhange-event), we dispatch this event only when there is no scheduled one in the queue. If we have already scheduled one but not get callbacked, we would skip to dispatch this event. To sum up, in this issue or mail thread, we only focus on what we did in the first CL. So previouly we think this is low-risk because we don't change anything at all. The real impact would happen in the second CL. So for the compat risk or maybe the potential for site breakage, maybe we could collect these data in the second CL. These are the main difference between the first CL and the second CL. If you have any other concerns, feel free to ping me! Thanks! On Wednesday, May 29, 2024 at 11:52:57 PM UTC+8 sligh...@chromium.org wrote: > hey folks, > > We spent a lot of time in API OWNERs today trying to understand this > change, and we couldn't crisply describe: > > > - What the old behaviour was > - What the new behaviour is going to be > - If we've analysed the potential for site breakage, and if not, if we > should be adding usecounters ahead of the change > > Most of this is stuff we'd expect to see in an Explainer. Is it possible > to produce one? Seeing example code for whatw this improves would be > helpful. > > Best, > > Alex > > On Wednesday, May 29, 2024 at 1:43:00 AM UTC-7 Yoav Weiss wrote: > >> I'm sorry, but re-reading this, I realized that I don't fully understand >> this change and the plan here. >> Can you elaborate on: >> * What is the behavior change that we want to drive here? >> * Which part of that would be covered by the first CL? which by the >> second? >> * Where do we predict compat risk here? How can we estimate it? >> >> Thanks! :) >> >> >> On Tue, May 28, 2024 at 1:54 AM Shuangshuang Zhou <shuangsh...@intel.com> >> wrote: >> >>> Hi Yoav, thanks for the question! From chromium's side, currently I >>> don't have any usecounters to trace how many sites would be impacted. I >>> checked WebKit' status, seems they don't have any data. Maybe Olli could >>> comment this from Gecko's side. >>> >>> Since the first CL doesn't change the original logic, we might collect >>> some data in the second CL(avoid to dispatch events that are already >>> scheduled but not executed). >>> >>> Thanks! >>> >>> On Monday, May 27, 2024 at 3:08:29 PM UTC+8 yoav...@chromium.org wrote: >>> >>>> Given Olli's comments on this change being backwards-incompatible, do >>>> we have any data on how many sites would be impacted? Any usecounters to >>>> that effect? >>>> >>>> On Mon, May 27, 2024 at 2:19 AM Shuangshuang Zhou < >>>> shuangsh...@intel.com> wrote: >>>> >>>>> Thanks Olli for the implement in Gecko side, and also Dan's comment! >>>>> >>>>> Hi Mike, would you please take a look and give some suggestion? Also, >>>>> seems we need 3 LGTMs, Kent or Mike, would you add another reviewer to to >>>>> take a review? >>>>> >>>>> Thanks! >>>>> On Saturday, May 25, 2024 at 1:05:59 AM UTC+8 Olli Pettay wrote: >>>>> >>>>>> I am trying to land the change, so it should be in FF 128 Nightly >>>>>> soon, next week at latest. So hopefully we'll get feedback if it breaks >>>>>> something. >>>>>> I don't think there is need for a standards-position for this >>>>>> particular small tweak. >>>>>> (But the process of making this kind of breaking spec change was >>>>>> rather unusual.) >>>>>> >>>>>> >>>>>> -Olli >>>>>> >>>>>> On Friday, May 24, 2024 at 7:55:44 PM UTC+3 Daniel Clark wrote: >>>>>> >>>>>>> Thanks Shuangshuang for clarifying what’s going on with these two >>>>>>> separate but related changes, and Olli for the update on >>>>>>> https://bugzilla.mozilla.org/show_bug.cgi?id=1898343. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Since Gecko already implements the behavior of firing >>>>>>> selectionchange on input/textarea (confirmed here >>>>>>> <https://glow-curvy-cerise.glitch.me/>), sounds good to me to go >>>>>>> ahead with shipping this change in Chromium (I’m not an API owner >>>>>>> though). >>>>>>> >>>>>>> >>>>>>> >>>>>>> Separately, for the behavior of not firing duplicate >>>>>>> selectionchange, it might not hurt to go ahead and request an official >>>>>>> Mozilla position on that since it sounds like there’s still a bit of >>>>>>> uncertainty about landing that change given back compat concerns, >>>>>>> unless >>>>>>> Olli confirms here that the plan is to go ahead and ship it. >>>>>>> >>>>>>> >>>>>>> >>>>>>> -- Dan >>>>>>> >>>>>>> >>>>>>> >>>>>>> *From:* Olli Pettay <ope...@mozilla.com> >>>>>>> *Sent:* Friday, May 24, 2024 12:26 AM >>>>>>> *To:* blink-dev <blin...@chromium.org> >>>>>>> *Cc:* Shuangshuang Zhou <shuangsh...@intel.com>; tk...@chromium.org >>>>>>> <tk...@chromium.org>; mike...@chromium.org <mike...@chromium.org>; >>>>>>> Daniel Clark <dan...@microsoft.com>; Olli Pettay <ope...@mozilla.com >>>>>>> > >>>>>>> *Subject:* Re: [blink-dev] Intent to Ship: Dispatch selectionchange >>>>>>> event per element >>>>>>> >>>>>>> >>>>>>> >>>>>>> You don't often get email from ope...@mozilla.com. Learn why this >>>>>>> is important <https://aka.ms/LearnAboutSenderIdentification> >>>>>>> >>>>>>> FWIW, I'm implementing the change in >>>>>>> https://bugzilla.mozilla.org/show_bug.cgi?id=1898343 >>>>>>> >>>>>>> Need to still fix some tests, which do reveal how the spec change >>>>>>> indeed isn't fully backwards compatible. >>>>>>> >>>>>>> Hopefully it doesn't break any real web sites. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> -Olli >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Friday, May 24, 2024 at 10:05:47 AM UTC+3 Shuangshuang Zhou >>>>>>> wrote: >>>>>>> >>>>>>> Hi Dan&Mike, I think we could submit a standard-position issue to >>>>>>> Mozilla for reducing duplicated events in our second CL(mentioned in my >>>>>>> last comment) for this feature. Because in the second CL, we might >>>>>>> change >>>>>>> the current logic of dispatching selectionchange event. For this time, >>>>>>> we >>>>>>> might just do it in chromium. WDYT? >>>>>>> >>>>>>> >>>>>>> >>>>>>> Thanks! >>>>>>> >>>>>>> On Friday, May 24, 2024 at 9:20:33 AM UTC+8 tk...@chromium.org >>>>>>> wrote: >>>>>>> >>>>>>> LGTM1. >>>>>>> >>>>>>> Firefox and Safari statuses are strong signals, and the >>>>>>> compatibility risk looks very low. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Thu, May 23, 2024 at 11:07 AM Shuangshuang Zhou < >>>>>>> shuangsh...@intel.com> wrote: >>>>>>> >>>>>>> Hi Dan&Mike, for your concern that Firefox is still failing the >>>>>>> WPTs at >>>>>>> https://wpt.fyi/results/selection/onselectionchange-on-distinct-text-controls.html, >>>>>>> >>>>>>> that might be another issue. Let me make more explanation. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Actually, the final goal of w3c modifys the spec of selectionchange >>>>>>> event is to avoid firing duplicated selectionchange event which are not >>>>>>> executed yet on the same element(as Rniwa commented in his comment >>>>>>> <https://github.com/w3c/selection-api/issues/170#issuecomment-1956096554>). >>>>>>> >>>>>>> Then in WebKit/WebCore, Rniwa submitted 2 CLs to achieve this ieda. The >>>>>>> first CL in WebKit is 276238@main >>>>>>> <https://commits.webkit.org/276238@main>, and in this CL they just >>>>>>> modified the logic to fire selectionchange event on input/textarea for >>>>>>> the >>>>>>> first step. Then the second CL in WebKit is 276388@main >>>>>>> <https://commits.webkit.org/276388@main>, which finally avoided to >>>>>>> fire duplicated selectionchange events according to the latest spec on >>>>>>> firing >>>>>>> selectionchange event >>>>>>> <https://w3c.github.io/selection-api/#firing-selectionhange-event>. >>>>>>> >>>>>>> >>>>>>> >>>>>>> So for this feature in Blink here , we also want to take 2 steps >>>>>>> like WebKit does that in the first CL we change to fire on >>>>>>> input/textarea >>>>>>> and then sovle the duplicated events in the second CL. And those tests >>>>>>> are >>>>>>> already modified to what both CLs are merged. So in the above test of >>>>>>> onselectionchange-on-distinct-text-controls.html, chrome and firefox >>>>>>> should >>>>>>> be failed because only Safari has landed 2 CLs to avoid duplicated >>>>>>> selectionchange events. Or in other words, firefox might already >>>>>>> dispatch >>>>>>> selectionchange event on elements but doesn't have the logic to avoid >>>>>>> to >>>>>>> fire scheduled-but-not-executed events. >>>>>>> >>>>>>> >>>>>>> >>>>>>> For WebKit, currently the two CLs are both landed in Safari >>>>>>> Technology Preview 192(link >>>>>>> <https://developer.apple.com/documentation/safari-technology-preview-release-notes/stp-release-192>), >>>>>>> >>>>>>> but it might need some time to ship in Safari because Safari is updated >>>>>>> within OS updates. >>>>>>> >>>>>>> For the status in FireFox, I'll double-check and confirm with >>>>>>> Tkent(one reviewer of my first CL). >>>>>>> >>>>>>> >>>>>>> >>>>>>> Thanks, >>>>>>> >>>>>>> Shuangshuang >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Thursday, May 23, 2024 at 9:29:59 AM UTC+8 mike...@chromium.org >>>>>>> wrote: >>>>>>> >>>>>>> Yes, agree. Can we please request a position from Mozilla at >>>>>>> https://github.com/mozilla/standards-positions/issues/new? >>>>>>> >>>>>>> On 5/22/24 6:43 PM, 'Daniel Clark' via blink-dev wrote: >>>>>>> >>>>>>> Yeah, that’s what I was trying to get at – the Intent implies that >>>>>>> Gecko has also shipped the breaking change but it seems that might not >>>>>>> be >>>>>>> the case. >>>>>>> >>>>>>> >>>>>>> >>>>>>> If not, we should send a Request for Position to figure out whether >>>>>>> there would be cross-browser alignment on shipping this. >>>>>>> >>>>>>> >>>>>>> >>>>>>> -- Dan >>>>>>> >>>>>>> >>>>>>> >>>>>>> *From:* Olli Pettay <ope...@mozilla.com> >>>>>>> *Sent:* Wednesday, May 22, 2024 9:53 AM >>>>>>> *To:* blink-dev <blin...@chromium.org> >>>>>>> *Cc:* Daniel Clark <dan...@microsoft.com>; Shuangshuang Zhou < >>>>>>> shuangsh...@intel.com> >>>>>>> *Subject:* Re: [blink-dev] Intent to Ship: Dispatch selectionchange >>>>>>> event per element >>>>>>> >>>>>>> >>>>>>> >>>>>>> You don't often get email from ope...@mozilla.com. Learn why this >>>>>>> is important <https://aka.ms/LearnAboutSenderIdentification> >>>>>>> >>>>>>> I think it is because of this rather surprising non-backwards >>>>>>> compatible recent change. >>>>>>> >>>>>>> On Wednesday, May 22, 2024 at 7:28:45 PM UTC+3 Daniel Clark wrote: >>>>>>> >>>>>>> The Gecko status is marked as Shipped/Shipping and the >>>>>>> Interop/Compat section mentions Firefox having shipped this, but >>>>>>> Firefox is >>>>>>> still failing the WPTs at >>>>>>> https://wpt.fyi/results/selection/onselectionchange-on-distinct-text-controls.html >>>>>>> . >>>>>>> >>>>>>> Can you help me understand the discrepancy there? >>>>>>> >>>>>>> >>>>>>> >>>>>>> Thanks, >>>>>>> >>>>>>> Dan >>>>>>> >>>>>>> >>>>>>> >>>>>>> *From:* blin...@chromium.org <blin...@chromium.org> *On Behalf Of >>>>>>> *Shuangshuang >>>>>>> Zhou >>>>>>> *Sent:* Tuesday, May 21, 2024 10:24 PM >>>>>>> *To:* blink-dev <blin...@chromium.org> >>>>>>> *Subject:* [blink-dev] Intent to Ship: Dispatch selectionchange >>>>>>> event per element >>>>>>> >>>>>>> >>>>>>> >>>>>>> You don't often get email from shuangsh...@intel.com. Learn why >>>>>>> this is important <https://aka.ms/LearnAboutSenderIdentification> >>>>>>> >>>>>>> *Contact **emails*shuangsh...@intel.com >>>>>>> >>>>>>> *Explainer*None >>>>>>> >>>>>>> *Specification* >>>>>>> https://w3c.github.io/selection-api/#selectionchange-event >>>>>>> >>>>>>> *Summary* >>>>>>> >>>>>>> Dispatches selectionchange event per element when this >>>>>>> element(input/textarea) provides a text selection or its selection >>>>>>> changes. >>>>>>> This is to match the latest specification of selectionchange event. >>>>>>> This >>>>>>> also matches Safari behavior. >>>>>>> >>>>>>> >>>>>>> >>>>>>> *Blink component*Blink>Editing>Selection >>>>>>> <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EEditing%3ESelection> >>>>>>> >>>>>>> *TAG review*None >>>>>>> >>>>>>> *TAG review status*Issues addressed >>>>>>> >>>>>>> *Risks* >>>>>>> >>>>>>> >>>>>>> >>>>>>> *Interoperability and Compatibility* >>>>>>> >>>>>>> Interoperability risk is low because Firefox and Safari have shipped >>>>>>> this according to the specification. Compatibility risk is low because >>>>>>> the >>>>>>> selectionchange event targeting input/textarea would bubble up, and >>>>>>> existing codes listening on Document will work well as ever. >>>>>>> >>>>>>> >>>>>>> >>>>>>> *Gecko*: Shipped/Shipping >>>>>>> >>>>>>> *WebKit*: Shipped/Shipping (https://commits.webkit.org/276238@main) >>>>>>> >>>>>>> *Web developers*: No signals >>>>>>> >>>>>>> *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?* >>>>>>> >>>>>>> Low WebView application risks. >>>>>>> >>>>>>> >>>>>>> >>>>>>> *Debuggability* >>>>>>> >>>>>>> None >>>>>>> >>>>>>> >>>>>>> >>>>>>> *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/selection/onselectionchange-on-distinct-text-controls.html >>>>>>> >>>>>>> >>>>>>> >>>>>>> *Flag name on chrome://flags*None >>>>>>> >>>>>>> *Finch feature name*DispatchSelectionchangeEventPerElement >>>>>>> >>>>>>> *Requires code in //chrome?*False >>>>>>> >>>>>>> *Tracking bug*https://issues.chromium.org/issues/330766600 >>>>>>> >>>>>>> *Estimated milestones* >>>>>>> Shipping on desktop >>>>>>> 127 >>>>>>> >>>>>>> *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/5255454895898624?gate=6043023317401600 >>>>>>> >>>>>>> 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/de18f3c4-df5a-4423-80ec-e505e0c9fb2bn%40chromium.org >>>>>>> >>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/de18f3c4-df5a-4423-80ec-e505e0c9fb2bn%40chromium.org?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/PH8PR00MB1445785C11C8FCA346EAE963C5EB2%40PH8PR00MB1445.namprd00.prod.outlook.com >>>>>>> >>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/PH8PR00MB1445785C11C8FCA346EAE963C5EB2%40PH8PR00MB1445.namprd00.prod.outlook.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/2d3b76b1-890f-4a07-961a-ef813c14eef3n%40chromium.org >>>>>>> >>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/2d3b76b1-890f-4a07-961a-ef813c14eef3n%40chromium.org?utm_medium=email&utm_source=footer> >>>>>>> . >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> -- >>>>>>> >>>>>>> TAMURA Kent >>>>>>> Software Engineer, Google >>>>>>> >>>>>>> -- >>>>> 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/b17e9c59-e826-44e3-9a52-e24067f1cbc9n%40chromium.org >>>>> >>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/b17e9c59-e826-44e3-9a52-e24067f1cbc9n%40chromium.org?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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