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Re: navigationStart and the actual start of the navigation

From: Przemysław Pietrzkiewicz <ppi@google.com>
Date: Fri, 27 Jun 2014 17:31:59 +0200
Message-ID: <CAMqrY-thPy6pgTNj4FL0EdgdPhmCUj1m6hpg1+qzEguwWSfbzg@mail.gmail.com>
To: Boris Zbarsky <bzbarsky@mit.edu>
Cc: public-web-perf@w3.org
I see, thanks for the explanation. In this case, maybe we could go for:

"This attribute must return the time when the user agent determines that
the navigation will happen. For navigations from documents other than the
initial about:blank of the browsing context, this is the time when the user
agent finishes prompting to unload the previous document."

Actually, the second sentence might be redundant - the time when the user
agent determines that the navigation will happen in the presence of a
document already loaded in the browsing context is the end of beforeunload.
For new browsing context this happens before about:blank is loaded, e.g.
when the user clicks on "open link in new tab".

Wdyt?

Cheers,
Przemek


On Fri, Jun 27, 2014 at 5:11 PM, Boris Zbarsky <bzbarsky@mit.edu> wrote:

> On 6/27/14, 9:39 AM, Przemysław Pietrzkiewicz wrote:
>
>> "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.
>>
>
> The only case in the spec when there is no previous document is when the
> document in question is the initial about:blank in the navigation context.
>  So "time the current document is created" is when the navigation context
> is created.
>
>
>  But this can happen long time after the "open link in new tab" button is
>> clicked.
>>
>
> Yes, agreed.  Navigation via window.open() has the same issue: it might
> take a while to actually open a window.  It would be nice to try to define
> this somehow in a way that makes sense for all browsers...
>
>
>  "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."
>>
>
> All navigations except initial about:blank are "from existing documents"
> in spec terms, so this phrasing wouldn't help the problem you're trying to
> solve, sadly.
>
> -Boris
>
>
Received on Friday, 27 June 2014 15:32:26 UTC

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