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Re: navigationStart and the actual start of the navigation

From: Arvind Jain <arvind@google.com>
Date: Fri, 27 Jun 2014 08:05:09 -0700
Message-ID: <CAOYaDdO5g=A5Q5mpGHp+nTyNVYjK__aXX0Hpiqif-CLMNgZHrw@mail.gmail.com>
To: Przemysław Pietrzkiewicz <ppi@google.com>, Boris Zbarsky <bzbarsky@mit.edu>
Cc: public-web-perf <public-web-perf@w3.org>, Tony Gentilcore <tonyg@google.com>, Camille Lamy <clamy@google.com>, Ilya Grigorik <igrigorik@google.com>
I browsed through the archives for how we ended up with the current
definition of navigationStart.

Please take a look at this thread:

Wonder if Boris has opinion on your suggested change.


On Fri, Jun 27, 2014 at 7:05 AM, Arvind Jain <arvind@google.com> wrote:
> It makes sense to me. I can make the change. Does anyone else have
> comments on this?
> On Fri, Jun 27, 2014 at 6:39 AM, Przemysław Pietrzkiewicz
> <ppi@google.com> wrote:
>> Hello,
>> navigationStart for navigations without the previous document is described
>> in [1] as follows:
>> "If there is no previous document, this attribute must return the time the
>> current document is created."
>> What does "time the current document is created" mean? If read in terms of
>> terminology we use in Chromium/Blink, that would be the time when we start
>> loading the page in the renderer.
>> But this can happen long time after the "open link in new tab" button is
>> clicked. For instance, on Android spawning a new renderer takes significant
>> time. Under current definition, the time needed to spawn the renderer would
>> not be represented in the reported values.
>> Would it make sense to define "navigationStart" as follows:
>> "This attribute must return the time when the user agent determines that the
>> navigation will happen. For navigations from existing documents, this is the
>> time when the user agent finishes prompting to unload the previous
>> document."
>> ?
>> Relevant discussion in the Chromium bug tracker: http://crbug.com/376004 .
>> Wdyt?
>> Cheers,
>> Przemek
>> [1]
>> https://dvcs.w3.org/hg/webperf/raw-file/tip/specs/NavigationTiming/Overview.html
Received on Friday, 27 June 2014 15:05:38 UTC

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