Bug 158720

Summary: Add support for <link rel=preload>
Product: WebKit Reporter: sideshowbarker <mike>
Component: Page LoadingAssignee: Yoav Weiss <yoav>
Severity: Normal CC: addyo, beidson, d, igrigorik, jaffathecake, katano3065, webkit, yoav
Priority: P2    
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
URL: https://w3c.github.io/preload/
Bug Depends on: 158466, 159872    
Bug Blocks:    

Description sideshowbarker 2016-06-13 19:53:19 PDT
Preload provides a declarative fetch primitive that initiates an early, high-priority, and non-render-blocking fetch and separates fetching from resource execution.
Declaratively specifies which resources (e.g., fonts) the user agent must fetch early to improve page performance.

- spec: https://w3c.github.io/preload/
- use cases: https://w3c.github.io/preload/#use-cases

Browser-engine support:

- Blink: Shipped in Chrome 50 https://developers.google.com/web/updates/2016/03/link-rel-preload?hl=en
- Edge: “Priority: Medium — Development is likely for a future release” https://developer.microsoft.com/en-us/microsoft-edge/platform/status/preload
- Gecko: Open feature bug https://bugzilla.mozilla.org/show_bug.cgi?id=1222633
Comment 1 Yoav Weiss 2016-06-14 00:22:52 PDT
I'm currently implementing this feature (but failing to assign this issue to myself *shrug*).

Related bugs:
https://bugs.webkit.org/show_bug.cgi?id=156334 - initial preload support
https://bugs.webkit.org/show_bug.cgi?id=157988 - Preload single download tests.
https://bugs.webkit.org/show_bug.cgi?id=156773 - LayoutTest http/tests/preload/dynamic_remove_preload_href.html is flaky on Mac and iOS
Comment 2 Yoav Weiss 2016-11-24 23:57:36 PST
Also related: https://bugs.webkit.org/show_bug.cgi?id=158466
Comment 3 Domenic Denicola 2017-04-26 11:37:07 PDT
Please note the tests at http://w3c-test.org/html/dom/reflection-metadata.html for link.as.
Comment 4 Jake Archibald 2017-05-25 08:54:31 PDT
I imagine it's in-progress, but neither fetch() or XHR appear to use the preload cache in the latest technology preview.
Comment 5 Addy Osmani 2017-08-21 10:47:55 PDT
Hey Yoav. Are there other blocking bugs to complete the link rel=preload implementation atm? Just came across https://bugs.webkit.org/show_bug.cgi?id=161952 but you might be keeping track of others.
Comment 6 Yoav Weiss 2017-08-22 03:32:42 PDT
No, just lost track of this issue :)

I think we can close this meta-bug and open new ones for eventual issues.