- From: Jan-Ivar Bruaroey via GitHub <sysbot+gh@w3.org>
- Date: Fri, 02 Dec 2022 22:19:41 +0000
- To: public-webrtc-logs@w3.org
jan-ivar has just created a new issue for https://github.com/w3c/webrtc-extensions: == Potential web compat issue with setOfferedRtpHeaderExtensions == I'm concerned about web compat over [this line](https://w3c.github.io/webrtc-extensions/#dom-rtcrtptransceiver-setofferedrtpheaderextensions): - _"2. If ext.[uri](https://www.w3.org/TR/webrtc/#dom-rtcrtpheaderextensioncapability-uri) value is not present in [[[HeaderExtensionsToOffer]]](https://w3c.github.io/webrtc-extensions/#dfn-headerextensionstooffer), [throw](https://webidl.spec.whatwg.org/#dfn-throw) a [NotSupportedError](https://webidl.spec.whatwg.org/#notsupportederror)."_ ...where [[HeaderExtensionsToOffer]] is [implementation-defined](https://infra.spec.whatwg.org/#implementation-defined). If _uri_ is a fixed string, that's a potential web compat headache. How is JS expected to use this API in a web compatible manner? 1. Come up with a subset tested to work in all browsers (today)? 2. Detect UA and pick from a map? 3. Write JS to pre-filter their input to [setOfferedRtpHeaderExtensions](https://w3c.github.io/webrtc-extensions/#dom-rtcrtptransceiver-setofferedrtpheaderextensions) using [headerExtensionsToOffer](https://w3c.github.io/webrtc-extensions/#dom-rtcrtptransceiver-headerextensionstooffer)? I found no example showing predicted use of this API, but I could imagine some sites being lazy and setting a fixed array and not testing it in all browsers before going to production. This might cause calls to outright fail in a particular browser; or even work today but fail later once some browser makes a change. This might also create a situation where browsers find it difficult to make changes later. Throwing also seems redundant, since JS can already read [[HeaderExtensionsToOffer]] using [headerExtensionsToOffer](https://w3c.github.io/webrtc-extensions/#dom-rtcrtptransceiver-headerextensionstooffer), and can query [headerExtensionsNegotiated](https://w3c.github.io/webrtc-extensions/#dom-rtcrtptransceiver-headerextensionsnegotiated) for the net result. Given this, maybe it's better for web compat to allow user agents to ignore values not present in [[HeaderExtensionsToOffer]]? Please view or discuss this issue at https://github.com/w3c/webrtc-extensions/issues/130 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Friday, 2 December 2022 22:19:43 UTC