Hey Avi! Two questions, one small, one large:
First, to reduce header bloat, the approach of not sending headers by default whose value is `?0` seems reasonable. Fetch Metadata's `Sec-Fetch-User` header <https://www.w3.org/TR/fetch-metadata/#abstract-opdef-set-user> is a good example of this. Can you help me understand why that's not the right thing to do here? Second, and more fundamentally, if we're not planning to remove `Save-Data`, adding this header doesn't make much sense to me. We'll be adding this new header to every request alongside `Save-Data`, with the same value as `Save-Data`. That feels purely duplicative. Can you help me understand the value? (If integration with permission policy is valuable (and I can understand how it could be!), did you consider carving out a naming exception for this header, and applying the policy control to the `Save-Data` header? It seems like we'd have to do that anyway in order for the policy control to have any meaning.) -mike On Wed, Mar 9, 2022 at 8:26 PM Ari Chivukula <[email protected]> wrote: > Sorry for not including timeline info. The plan is: > M102 will include the new Sec-CH-Save-Data header. > No plan to remove the legacy Save-Data header at this moment. > > > On Mon, Mar 7, 2022 at 7:57 AM Ari Chivukula <[email protected]> wrote: > >> Fixing the subject prefix, apologies. >> >> On Mon, Mar 7, 2022 at 7:55 AM Ari Chivukula <[email protected]> >> wrote: >> >>> Contact emails >>> >>> [email protected], [email protected], [email protected] >>> >>> Design Doc >>> >>> >>> https://docs.google.com/document/d/1sRYGWL2H_qFQamffUbojBiQdbJ1uAmptr3F_jjx5VSI/edit >>> >>> Specification >>> >>> https://wicg.github.io/savedata/ >>> >>> https://wicg.github.io/client-hints-infrastructure/ >>> >>> Summary >>> >>> The Sec-CH-Save-Data client hint >>> <https://wicg.github.io/client-hints-infrastructure/> indicates whether >>> the user agent intends to reduce data usage. It will be sent by default on >>> all requests unless the permissions policy says otherwise. >>> >>> >>> >>> For example, one could limit delegation of this hint via HTTP headers: >>> >>> Permissions-Policy: ch-save-data=(self, https://bar.com/) >>> >>> >>> >>> Or, one could limit delegation of this hint via an HTML meta tag: >>> >>> <meta name="Accept-CH" content="sec-ch-save-data=(https://bar.com/)"> >>> >>> >>> >>> Example of new HTTP header when Data Saver is on: >>> >>> Sec-CH-Save-Data: ?1 >>> >>> >>> >>> Example of new HTTP header when Data Saver is off: >>> >>> Sec-CH-Save-Data: ?0 >>> >>> >>> >>> Explicitly requesting Sec-CH-Save-Data or modifying the CH-Save-Data >>> permissions policy will prevent the old `Save-Data` header from being >>> sent. Otherwise, the old header will not be affected. >>> >>> >>> >>> Blink component >>> >>> Blink>Network>ClientHints >>> <https://bugs.chromium.org/p/chromium/issues/list?q=component%3ABlink%3ENetwork%3EClientHints> >>> >>> >>> >>> Motivation >>> >>> The current `Save-Data` header is sent when a browser or operating >>> system data saver setting is on (e.g., Lite mode >>> <https://support.google.com/chrome/answer/2392284?hl=en&co=GENIE.Platform%3DAndroid>) >>> for all first and third party requests, lives outside the client hints >>> system <https://wicg.github.io/client-hints-infrastructure/>, and is named >>> improperly >>> <https://docs.google.com/document/u/1/d/1yhVLyEIpDhhDQf698WkvXBiPcLwxEgCBI4o1FjvXwfM/edit>. >>> `Sec-CH-Save-Data` will be a proper client hint and its delegation to third >>> parties could be prevented via permissions policies >>> <https://wicg.github.io/client-hints-infrastructure/#policy-controlled-features> >>> . >>> >>> TAG review >>> >>> N/A (No new data is exposed that wasn't before) >>> >>> Compatibility >>> >>> The `Save-Data` header will not be removed, so adoption of >>> `Sec-CH-Save-Data` is optional. >>> >>> >>> Interoperability >>> >>> Gecko: Client Hints not yet implemented (considered non-harmful >>> <https://mozilla.github.io/standards-positions/#http-client-hints>) >>> >>> WebKit: Client Hints not yet implemented >>> >>> Web developers: No feedback yet >>> >>> Debuggability >>> >>> N/A >>> >>> Is this feature fully tested by web-platform-tests? >>> >>> Not yet, but it will be. `Save-Data` tests are here >>> <https://github.com/web-platform-tests/wpt/search?q=save-data>. >>> >>> Tracking bug >>> >>> https://crbug.com/1293443 >>> >>> Link to entry on the Chrome Platform Status >>> >>> https://chromestatus.com/feature/5645928215085056 >>> >>> -- > 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 [email protected]. > To view this discussion on the web visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAGpy5DLyhJURaZAKrogjcs0QEMV0-3JM0_onQOP-GjBVY2gkXQ%40mail.gmail.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAGpy5DLyhJURaZAKrogjcs0QEMV0-3JM0_onQOP-GjBVY2gkXQ%40mail.gmail.com?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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