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Re: Executing script-inserted external scripts in insertion order

From: Adam Barth <w3c@adambarth.com>
Date: Fri, 15 Oct 2010 00:52:12 -0700
Message-ID: <AANLkTin7wJJrFZm=rcKd+JF1ANq0KdhmNvJe1wAut=+y@mail.gmail.com>
To: Henri Sivonen <hsivonen@iki.fi>
Cc: Tony Gentilcore <tonyg@chromium.org>, public html <public-html@w3.org>
On Fri, Oct 15, 2010 at 12:12 AM, Henri Sivonen <hsivonen@iki.fi> wrote:
> Tony Gentilcore's reply to public-html bounced, so I'm quoting it here in full with his permission.
> On Oct 14, 2010, at 21:35, Tony Gentilcore wrote:
>
>> Re: Changing WebKit to preserve order for script-inserted external scripts.
>> In short, I believe that the current WebKit behavior results in the
>> best performance for current web content with no known major compat
>> problems.
>>
>> Expanding on that, my opinion is that developers who don't understand
>> the intricacies of script execution order, typically use
>> parser-inserted scripts which preserve order by default. In my
>> experience working on Google web properties, developers turn to
>> script-inserted scripts only when they want a performance gain from
>> async behavior. Now we've avoided the need to turn to script-inserted
>> scripts to gain async behavior by adding the async attribute to
>> parser-inserted scripts, but not many people have migrated to that
>> yet. If we were to change the behavior of script-inserted external
>> script to preserve the order, I suspect we'd just take a perf hit with
>> no concrete compat benefit. That being said, I wouldn't try to stand
>> in the way of this change, but I certainly don't want to be the one to
>> implement it.
>>
>> Re: Prefetching scripts with type=text/cache.
>> As of http://trac.webkit.org/changeset/67245, WebKit is in compliance
>> with HTML5 and no longer hits the network for scripts it doesn't plan
>> to execute. <link rel=prefetch> should be used for prefetching.
>
> Thanks for the reply. Your position on the default is what I feared it would be.
>
> About prefetching: From the changeset you linked to, it seems to me that WebKit trunk is now breaking existing LABjs and RequireJS in their ordered modes. Is <link rel=prefetch> your only current plan for providing a future version of LABjs something to restore functionality with?

Do you have example sites that use these libraries in a mode that's
now broken?  I'm not familiar with these libraries.

Adam
Received on Friday, 15 October 2010 08:01:35 GMT

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