Thanks for your feedback on this intent! We plan on modifying the "Allow-Cross-Origin-Event-Reporting" response header to accept a boolean instead of a string literal to match the preferred convention for response headers.
On Thursday, May 9, 2024 at 1:21:43 PM UTC-4 Liam Brady wrote: > Can I ask why string literal vs boolean? > > > I had done this to match the convention already being used for other > Protected Audience-related response headers (such as > Ad-Auction-Allowed/X-Allow-FLEDGE > <https://source.chromium.org/chromium/chromium/src/+/main:content/services/auction_worklet/public/cpp/auction_downloader.cc;l=413-429;drc=b8ddddd3dfef89a597a4e89d8cc76bcf8a15d655>). > > At the time of implementation, I wasn't aware of the preferred boolean > convention of "?0" and "?1" defined in RFC8941 > <https://www.rfc-editor.org/rfc/rfc8941#name-booleans>. Even though this > isn't what's preferred, I think it should still be fine to keep in place > for now, and being consistent with the rest of the Protected Audience API > is always a plus. > > On Thu, May 9, 2024 at 12:19 PM Mike Taylor <mike...@chromium.org> wrote: > >> On 5/9/24 12:13 PM, Liam Brady wrote: >> >> Can you clarify what the type is for this new header? It reads as if >>> you're adding a String Item that looks like a boolean, rather than a >>> Boolean Item. Is that correct? It doesn't seem to be actually defined in >>> the spec. >> >> >> This is meant to be a string literal that is either "true" or "false". I >> have a spec PR <https://github.com/WICG/fenced-frame/pull/159> up to >> formally define that and remove any confusion over what values it's >> expecting. Thanks for calling this out! >> >> Can I ask why string literal vs boolean? >> >> >> This change would impact the ability of first parties to regulate and >>> prevent reportEvent beacons. Although this requires mutual opt-in, I expect >>> scenarios to eventually come up where a site owner wants to allow >>> cross-origin reportEvent only for certain origins. >> >> >> To clarify the first party piece, control over sending reportEvent() >> beacons rests within the worklet owner that invokes >> registerAdBeacon()/registerAdMacro() i.e. seller/ buyer and the document >> loaded with the main ad renderURL (i.e. the buyer/advertisers). The >> first-party (i.e. the publishers) don't have control over reportEvent() >> beacons since that is considered part of the overall Protected Audience >> API, and this feature doesn't change that. >> >> On Wed, May 8, 2024 at 1:27 PM Mike Taylor <mike...@chromium.org> wrote: >> >>> On 5/8/24 11:30 AM, 'Liam Brady' via blink-dev wrote: >>> >>> Contact emails >>> >>> lbr...@google.com, shiva...@chromium.org, jka...@chromium.org >>> >>> Explainer(s) >>> >>> https://github.com/WICG/turtledove/pull/1134 >>> >>> Spec(s) >>> >>> https://github.com/WICG/fenced-frame/pull/152 >>> >>> Summary >>> >>> Ad frames (both fenced frames and urn-iframes) created through a >>> Protected Audience auction, as well as their same-origin nested iframes, >>> are allowed to call reportEvent() API >>> <https://github.com/WICG/turtledove/blob/main/Fenced_Frames_Ads_Reporting.md#reportevent-preregistered-destination-url> >>> >>> to send event-level reports. It's also important for third-parties on >>> Protected Audience-created ads to have the same measurement and reporting >>> capabilities for spam detection, brand safety, and measurement >>> verification. However, the API as it exists currently has a same-origin >>> child iframe restriction which poses a complication as described below. >>> >>> If an ad buyer wins an ad auction and its ad frame is displayed on a >>> page, it might choose to embed a subframe that points to a third-party >>> server that hosts the actual ad instead. With this use case, and with the >>> current state of the reportEvent() API, the actual ad's document cannot >>> directly call reportEvent() the way that its embedder can since the >>> document is in a cross-origin nested iframe. Instead, it has to get its >>> embedder to actually send the beacon by letting the embedder know via a >>> postMessage. This will not be an ergonomic solution for this use case. >>> >>> With this change, a cross-origin subframe can opt in to sending >>> reportEvent() beacons using its ancestor's reporting metadata by calling >>> reportEvent() with the parameter crossOriginExposed=true. This is the same >>> syntax as is currently used by the main render URL frame to opt in to >>> sending cross-origin automatic beacons with data (this means the FenceEvent >>> IDL will stay the same). >>> >>> The main ad render URL frame will opt in with a new >>> "Allow-Cross-Origin-Event-Reporting" response header. Its valid values will >>> be true and false, and will default to false when omitted. This will not be >>> required for documents that are same-origin to the FencedFrameConfig's >>> mapped url. >>> >>> Can you clarify what the type is for this new header? It reads as if >>> you're adding a String Item that looks like a boolean, rather than a >>> Boolean Item. Is that correct? It doesn't seem to be actually defined in >>> the spec. >>> >>> (I filed https://github.com/WICG/fenced-frame/issues/158 for that.) >>> >>> >>> This is a convenience change (not privacy impacting), as it's already >>> possible (but cumbersome) for the third-party to postMessage the parent >>> frame to send the report on their behalf. For security reasons, the >>> proposal requires opt-ins from both the main ad frame and the cross-origin >>> iframe. >>> >>> Blink component >>> >>> Blink>FencedFrames >>> <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EFencedFrames> >>> >>> TAG reviews and status >>> >>> Fenced frames existing TAG review appended with these spec changes >>> https://github.com/w3ctag/design-reviews/issues/838# >>> <https://github.com/w3ctag/design-reviews/issues/838#issuecomment-1792881253> >>> >>> Link to Origin Trial feedback summary >>> >>> No Origin Trial performed >>> >>> Is this feature supported on all six Blink platforms (Windows, Mac, >>> Linux, Chrome OS, Android, and Android WebView)? >>> >>> Supported on all the above platforms except Android WebView. >>> >>> Debuggability >>> >>> Additional debugging capabilities are not necessary for these feature >>> changes. >>> >>> Risks >>> >>> Compatibility >>> >>> This is an added functionality and is backward compatible. >>> >>> Interoperability >>> >>> There are no interoperability risks as no other browsers have decided to >>> implement these features yet. We have not received any standards positions >>> from Mozilla <https://github.com/mozilla/standards-positions/issues/781> >>> or Webkit <https://github.com/WebKit/standards-positions/issues/173>. >>> >>> Is this feature fully tested by web-platform-tests >>> <https://chromium.googlesource.com/chromium/src/+/master/docs/testing/web_platform_tests.md>? >>> >>> Link to test suite results from wpt.fyi. >>> >>> Yes. New reportEvent() beacon tests have been added to test cross-origin >>> beacons. >>> >>> fence-report-event-cross-origin-content-initiated.https.html (test >>> <https://github.com/web-platform-tests/wpt/blob/master/fenced-frame/fence-report-event-cross-origin-content-initiated.https.html>) >>> >>> (results >>> <https://wpt.fyi/results/fenced-frame/fence-report-event-cross-origin-content-initiated.https.html> >>> ) >>> >>> fence-report-event-cross-origin-nested-urn-iframe.https.html (test >>> <https://github.com/web-platform-tests/wpt/blob/master/fenced-frame/fence-report-event-cross-origin-nested-urn-iframe.https.html>) >>> >>> (results >>> <https://wpt.fyi/results/fenced-frame/fence-report-event-cross-origin-nested-urn-iframe.https.html> >>> ) >>> >>> fence-report-event-cross-origin-nested.https.html (test >>> <https://github.com/web-platform-tests/wpt/blob/master/fenced-frame/fence-report-event-cross-origin-nested.https.html>) >>> >>> (results >>> <https://wpt.fyi/results/fenced-frame/fence-report-event-cross-origin-nested.https.html> >>> ) >>> >>> fence-report-event-cross-origin-no-embedder-opt-in.https.html (test >>> <https://github.com/web-platform-tests/wpt/blob/master/fenced-frame/fence-report-event-cross-origin-no-embedder-opt-in.https.html>) >>> >>> (results >>> <https://wpt.fyi/results/fenced-frame/fence-report-event-cross-origin-no-embedder-opt-in.https.html> >>> ) >>> >>> fence-report-event-cross-origin-no-subframe-opt-in.https.html (test >>> <https://github.com/web-platform-tests/wpt/blob/master/fenced-frame/fence-report-event-cross-origin-no-subframe-opt-in.https.html>) >>> >>> (results >>> <https://wpt.fyi/results/fenced-frame/fence-report-event-cross-origin-no-subframe-opt-in.https.html> >>> ) >>> >>> fence-report-event-cross-origin-urn-iframe-content-initiated.https.html ( >>> test >>> <https://github.com/web-platform-tests/wpt/blob/master/fenced-frame/fence-report-event-cross-origin-urn-iframe-content-initiated.https.html>) >>> >>> (results >>> <https://wpt.fyi/results/fenced-frame/fence-report-event-cross-origin-urn-iframe-content-initiated.https.html> >>> ) >>> >>> fence-report-event-cross-origin-urn-iframe-no-embedder-opt-in.https.html >>> (test >>> <https://github.com/web-platform-tests/wpt/blob/master/fenced-frame/fence-report-event-cross-origin-urn-iframe-no-embedder-opt-in.https.html>) >>> >>> (results >>> <https://wpt.fyi/results/fenced-frame/fence-report-event-cross-origin-urn-iframe-no-embedder-opt-in.https.html> >>> ) >>> >>> fence-report-event-cross-origin-urn-iframe-no-subframe-opt-in.https.html >>> (test >>> <https://github.com/web-platform-tests/wpt/blob/master/fenced-frame/fence-report-event-cross-origin-urn-iframe-no-subframe-opt-in.https.html>) >>> >>> (results >>> <https://wpt.fyi/results/fenced-frame/fence-report-event-cross-origin-urn-iframe-no-subframe-opt-in.https.html> >>> ) >>> >>> fence-report-event-cross-origin-urn-iframe.https.html (test >>> <https://github.com/web-platform-tests/wpt/blob/master/fenced-frame/fence-report-event-cross-origin-urn-iframe.https.html>) >>> >>> (results >>> <https://wpt.fyi/results/fenced-frame/fence-report-event-cross-origin-urn-iframe.https.html> >>> ) >>> >>> fence-report-event-cross-origin.https.html (test >>> <https://github.com/web-platform-tests/wpt/blob/master/fenced-frame/fence-report-event-cross-origin.https.html>) >>> >>> (results >>> <https://wpt.fyi/results/fenced-frame/fence-report-event-cross-origin.https.html> >>> ) >>> >>> fence-report-event-sub-fencedframe.https.html (test >>> <https://github.com/web-platform-tests/wpt/blob/master/fenced-frame/fence-report-event-sub-fencedframe.https.html>) >>> >>> (results >>> <https://wpt.fyi/results/fenced-frame/fence-report-event-sub-fencedframe.https.html> >>> ) >>> >>> WPT directory for Fenced Frames: >>> https://github.com/web-platform-tests/wpt/tree/master/fenced-frame >>> >>> Anticipated spec changes >>> >>> None >>> >>> Link to entry on the Chrome Platform Status >>> >>> https://chromestatus.com/feature/5113611084365824 >>> >>> Links to previous Intent discussions >>> >>> Fenced Frame Intent to prototype: >>> https://groups.google.com/a/chromium.org/g/blink-dev/c/Ko9UXQYPgUE/m/URRsB-qvAAAJ >>> >>> >>> Fenced Frame Intent to experiment: >>> https://groups.google.com/a/chromium.org/g/blink-dev/c/y6G3cvKXjlg/m/Lcpmpi_LAgAJ >>> >>> >>> Fenced Frame Intent to ship: >>> >>> >>> https://groups.google.com/a/chromium.org/g/blink-dev/c/tpw8wW0VenQ/m/mePLTiHlDQAJ >>> -- >>> 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 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