RE: [Resource Timing] Opt in vs Opt Out and initiatorType attribute

Hi Andy,

Thanks for providing feedback.

There are two issues here: opting in or out of the entire timing feature by default and opting in or out of the sharing detailed attribute information to third party origins. For the first issue, the working group strongly feels that we should opt into the timing feature by default. We have analyzed the performance impact and it is minimal. Further, we feel that adoption for this feature will be much greater when the feature is on by default. A user agent is able to provide a UA setting to opt out of the feature if they want, however, no UA feels this way currently.

As for opting in or opting out of sharing detailed attribute information to third party origins, the working group has strongly felt that we should opt out by default. By default, we only share the startTime, responseEnd and the duration information with third party origins. With the Timing-Allow-Origin Response Header, you can "opt in" and allow all or certain origins to that detailed information.

>In the latest editor's draft of the spec The initiatorType attribute
>has changed from an integer to a string, can anyone explain the
>thinking behind this (it's more for my curiosity, but I see the
>attribute in PerformanceNavigation spec are integers)

There have been many public discussions on various W3C mailing lists on the merits of enumerated strings versus numeric constants (See here: http://lists.w3.org/Archives/Public/public-script-coord/2012JanMar/0320.html). We have updated this spec per that recommendation.

Thanks,
Jatinder

Received on Wednesday, 7 March 2012 19:38:42 UTC