Re: Where are instances of PerformanceNavigationTiming created?

On Thu, 2014-07-10 at 12:19 -0400, Boris Zbarsky wrote:
> On 7/10/14, 11:48 AM, Philippe Le Hegaret wrote:
> > On Wed, 2014-07-09 at 21:27 -0400, Boris Zbarsky wrote:
> >> When, exactly, are these steps executed?  That doesn't seem to be
> >> stated.  Presumably this is meant to hook into the "navigate" algorithm
> >> somehow, right?
> >
> > It is hooked into fetch, like "immediately before a user agent starts
> > the fetching process", then current document readiness states.
> 
> Is that in the fetch spec?  Because the only instance of that text in 
> https://dvcs.w3.org/hg/webperf/raw-file/tip/specs/NavigationTiming2/Overview.html 
> is in step 10 of the processing model, which is obviously after step 2.

(skipped that one earlier for no reason)

This would come back to the separate thread on "navigationStart and the
actual start of the navigation" then. In other words, we could say the
following:
[[
- set startTime to 0 as step 0 of unloading the previous document, if
any, or as the first step before the page load processing model".
]]

Btw, I believe we need to be clearer on nested browsing contexts. In
Firefox, only the top-level browsing context takes the previous document
into account. Any nested browsing context will always have 0 for
unloadEventStart and unloadEventEnd. In Chrome however, it will take
into account any navigation within the nested context. See simple test
at [1]. I didn't try with IE but it seems to me that the behavior of
Chrome is the expected one for proper user perception expectation.

Philippe

[1] http://jay.w3.org/~plehegar/navigation.html

Received on Thursday, 10 July 2014 19:28:17 UTC