Comments on: Delayed Script Execution; An Opera feature that has Steve excited

By: justinnt

justinnt — Mon, 15 Sep 2008 00:42:28 +0000

Thanks Steve for alerting us to this hiding feature. but, to your conclusion:
What’s all the excitement?!

Do web developers really need a browser switch to see the impact of delay-loading their JavaScript??
I don’t see what’s complex about asynchronous script loading :
I break my scripts into two sets : those I need on pageload, and the rest. After displaying some welcoming html, a tiny script pulls in the first compacted payload via xmlhttp After this runs all initialisation and re-rendering, just wait a moment before requesting the remaining (second) compacted payload. I have yet to need to trip more specialised scripts, but once the initial libraries are loaded there’s nothing complex about using available frameworks for further asynchronous loading.

and do we want to facilitate the use of document.write in ads?
I have no empathy with those devilopers pulling in ads, but, given they’re out there, I agree the browser feature is a useful one for users.
OK eyelidlessness, your scenario is totally plausible, but why would we care about nurturing bad practice?

so I agree this is a good browser feature, but I’m not concerned with programatically switching it, because we don’t need document.write

By: souders

souders — Sat, 13 Sep 2008 08:06:20 +0000

The main use of document.write is in ads, where 3rd party content is being stuffed into pages. In this situation it’s not realistic for the ad developer and web site developer to agree on how to integrate their code. To get the ad inserted in the right place they use document.write.

Here’s an example from AOL (not picking on them – notice they use Doubleclick). They include a script – http://twx.doubleclick.net/adj/TW.AOLCom/Site_WS_3;MN=93227127;u=r572ebd845c53ba7d;wm=o;tac=51095;rm=1;!c=d-jav;sz=300x250;tile=3;dcove=d;ord=292563415? . The script contains document.write(''). (I’ve omitted the anchor wrapping the image.)

Improving the way ads are served is one of the top 3 most important performance challenges today (the other 2 are javascript and widgets).

By: eyelidlessness

eyelidlessness — Fri, 12 Sep 2008 17:51:20 +0000

“People actually use document.write for scripts?”
.
Well, a lot of people used to. Some older scripts still in use do. It’s still quite common to use on iframes, though I don’t think that’d suffer from a deferred script issue as the parent document would have already been rendered. At any rate, someone might want to use legacy code rather than rewriting, but may still want to improve performance for end users using some kind of delayed execution, in which case one would want to not break document.write().
.
Note, I’m not defending all of that. Just saying it’s plausible.

By: TNO

TNO — Fri, 12 Sep 2008 14:32:29 +0000

People actually use document.write for scripts? Whatever happened to creating a node/fragment and then appending it?

By: ThomasHansen

ThomasHansen — Fri, 12 Sep 2008 12:56:31 +0000

6 letters…?
That’s 13 letters actually unless you don’t use XHTML but relies on normal HTML…
defer=”defer”
;)