FetchLater

[mingyc]

Specification

whatwg/fetch#1647

Description

Propose to add a new feature FetchLater for the corresponding JS API.

Documentation

https://github.com/WICG/pending-beacon/blob/main/docs/fetch-later-api.md

Browser support

• Chrome: https://chromestatus.com/feature/4654499737632768
• WebKit: https://bugs.webkit.org/show_bug.cgi?id=284347
• Gecko: https://bugzilla.mozilla.org/show_bug.cgi?id=1936180

[captainbrosset]

Thank you, we should indeed add this. The feature is shipping with Chrome and Edge 134.
Note that BCD has not yet been updated for Chrome Beta 134, at least I don't think it has. @Elchi3 can you confirm?

[Elchi3]

I saw and tested this but I haven't confirmed it shipping in Chrome 134 beta.

[mingyc]

We haven't enabled it for M134 Beta yet.

[mingyc]

Sorry maybe a noob question, but if we are already using Chromium WebFeature for FetchLater. Do we still need to switch to WebDXFeature, or can we log both?

[captainbrosset]

We haven't enabled it for M134 Beta yet.

https://chromestatus.com/roadmap still has it as part of 134. Will it stay on 134, or likely move out to a later release?

Sorry maybe a noob question, but if we are already using Chromium WebFeature for FetchLater. Do we still need to switch to WebDXFeature, or can we log both?

Maybe @foolip will know how to reply to this, I'm not sure I understand what you mean by "Chromium WebFeature" vs. "WebDXFeature". I'm guessing this is about use-counters, but not sure.

[atopal]

@mingyc assuming you're talking about use counters, you'd have to add a WebDXFeature use counter, even if you already added an old style WebFeature use counter already, but you can have both, no problem. Keep in mind, WebDXFeatures are different from old style use counters in that there is a 1:1 mapping between a use counter and a feature, they measure usage on a high level feature level, more about that in the public doc.

[foolip]

@mingyc you must mean WebFeature::kFetchLater which is the classic use counter, the kind that we show data from on chromestatus.com. You can absolutely keep such use counters, and just add a simple mapping from them to "WebDXFeature" which is organized around web-features. https://chromium-review.googlesource.com/c/chromium/src/+/6269037 is an example of this I did recently.

[mingyc]

Update: The launch is delayed to M135.

I've also sent out https://chromium-review.googlesource.com/c/chromium/src/+/6310147 as suggested above to map the classic use counter.

[ErwinHofmanRV]

+1 from RUMvision (as we're writing a blogpost covering the deprecation of unload and alternatives like beforeunload, pagehide, visibilitychange and fetchLater and then concluded that we couldn't add a baseline-component for our fetchLater chapter yet 😅 )

[Elchi3]

It is in Chromium 135. I collected compat data for it in mdn/browser-compat-data#26135

The keys are:

• api.FetchLaterResult
• api.FetchLaterResult.activated
• api.Window.fetchLater

So, someone should create a web-feature with these BCD keys.

[captainbrosset]

I'll take this one.

[captainbrosset]

@mingyc could you please take a look at #2771 and review the feature description in the yml file?