Modifying +layout.server.js (caching) responses headers

[kael]

Is it possible to modify layouts responses headers ?

I'd like to set caching headers (etag) on some +layout.server.js that return data that take some time to be processed.

Testing with the following code:

// +layout.server.js

import { fetchData } from '$api/data';

export function load({ url, setHeaders }) {
  const id = url.searchParams.get('id')
  setHeaders({ etag: "bar" });
  return {
    resource: fetchData(id),
  };
}

the etag is not set to layout headers but to the main requested url ones.

Is there some way to add caching headers to +server.layout.js ?

[stephane-vanraes]

the etag is not set to layout headers but to the main requested url ones.

layouts are not pages, they cannot have their own headers, the setHeaders here will set the headers on the requested page