jQuery Anti-Patterns for Performance
September 11th, 2009
Heyo, I'm Paul Irish.
I'm
a front-end developer,
a Google Chrome dev relations guy,
a jQuery Team member,
a developer of Modernizr, CSS3 Please and HTML5 Boilerplate,
a host on the yayQuery Podcast,
and
an mp3 blogger at Aurgasm.
Just moved to San Francisco.
Contact me or read more about me. Or both!
Follow me on twitter: @paul_irish
Nice presentation dude. Great slides.
Wish I coulda been there to see it in person!
Big Loada!
Thanks for nice slides. Nice tip/trick on slide 36…in need of this right now. :)
too bad I couldn't be there :'(
@Pablo, Hah! thank you for getting the reference. :) Craig David and Squarepusher ref's on a talk about selectors is just.. a must do!
So in general my recommendation was to not use the context argument for any perf advantage, I only see it useful as a shorter way of writing $(this).find(…
But Yehuda Katz mentioned that it has a decent use in live() in jquery 1.3.3:
$("td", "table").live(…
will scope the delegation to existing tables
I have yet to do some performance testing on this. But this may be worth considering.
Paul, thanks for a fascinating presentation. I wish I could have heard you too. I'm just getting into jquery so it was illuminating. It brought back some of my best programmer's instinct. :)
…and I've picked up your RSS feed!
Great presentation Paul! My fav slide is #54 — All that expression'y goodness! :D
@Paul:
will not be scoped to tables, because the context of the resulting jQuery object is still the document. To change the context you have to pass an actual DOM node.
I think we're going to be seeing a lot of code like this when v1.4 hits the shelves:
Prestaul, you are 100% correct.
This definitely lends to some odd looking code, but yah right now that's the best way…
Very-very nice and usefull. I take couple of your recepies. Thank you.
This is a great presentation. Thanks!
Looks like the slides are down :(