Usage example for crossorigin use in Link header.

[jdalton]

I noticed that prefetch can specify crossorigin attirbute when using the link tag. Could there also be an example of handling it with the Link: header.

A follow-up would be expanding on what are the accepted values of linkElement.crossOrigin=.... Is it just string values or will a boolean true or an empty string "" be treated as "anonymous"?

[yoavweiss]

The crossorigin attribute on link elements is identical to other elements. For values see https://html.spec.whatwg.org/#cors-settings-attributes or https://developer.mozilla.org/en-US/docs/Web/HTML/CORS_settings_attributes

Adding it as an attribute to headers is identical to other attributes: e.g.
Link: <https://example.com/logo-hires.jpg>; rel=prefetch; as=image; crossorigin
or
Link: <https://example.com/logo-hires.jpg>; rel=prefetch; as=image; crossorigin=anonymous

Do you think the spec is not clear enough on that front?

[jdalton]

Ya, I eventually put it together looking at other blog posts / references. With CORS being its own header initially I wasn't sure if that would be tackled somewhere else.

[staabm]

was also searching exactly that and found the example here.

I guess it would also be helpful for others to have a crossorgin example in the spec.
(I searched the spec before finding this issue via google)

[yoavweiss]

/cc @noamr - can you incorporate such an example into whatwg/html#7622 ?

[yoavweiss]

The behavior of Link headers and crossorigin is now defined in https://html.spec.whatwg.org/#processing-link-headers
If there's a need to further document crossorigin specifically, the relevant MDN article is probably the best place.