Optimize jQuery.expr.filters.hidden

Reported by:	dmethvin	Owned by:	timmywil
Priority:	low	Milestone:	1.9
Component:	css	Version:	1.8.3
Keywords:		Cc:
Blocked by:		Blocking:

Description

http://forum.jquery.com/topic/optimize-jquery-expr-filters-hidden

Wouldn't it make sense to alter the order of the expressions in jQuery.expr.filters.hidden to only do the expensive work (elem.offsetWidth) after evaluating the parts that don't trigger a reflow? In the case the element is determined to be hidden by the style, it does not trigger a reflow anymore, what would be a nice behavior for a hidden element.

So instead of

return ( elem.offsetWidth === 0 && elem.offsetHeight === 0 ) || (!jQuery.support.reliableHiddenOffsets && ((elem.style && elem.style.display) || curCSS( elem, "display" )) === "none");

return (!jQuery.support.reliableHiddenOffsets && ((elem.style && elem.style.display) || curCSS( elem, "display" )) === "none") || ( elem.offsetWidth === 0 && elem.offsetHeight === 0 );

Roel

Attachments (0)

Change History (7)

Changed November 12, 2012 03:33PM UTC by dmethvin comment:1

component:	unfiled → css
description:	http://forum.jquery.com/topic/optimize-jquery-expr-filters-hidden \ \ Wouldn't it make sense to alter the order of the expressions in jQuery.expr.filters.hidden to only do the expensive work (elem.offsetWidth) after evaluating the parts that don't trigger a reflow? In the case the element is determined to be hidden by the style, it does not trigger a reflow anymore, what would be a nice behavior for a hidden element. \ \ So instead of \ \ return ( elem.offsetWidth === 0 && elem.offsetHeight === 0 ) \|\| (!jQuery.support.reliableHiddenOffsets && ((elem.style && elem.style.display) \|\| curCSS( elem, "display" )) === "none"); \ do \ \ return (!jQuery.support.reliableHiddenOffsets && ((elem.style && elem.style.display) \|\| curCSS( elem, "display" )) === "none") \|\| ( elem.offsetWidth === 0 && elem.offsetHeight === 0 ); \ Roel → http://forum.jquery.com/topic/optimize-jquery-expr-filters-hidden \ \ Wouldn't it make sense to alter the order of the expressions in jQuery.expr.filters.hidden to only do the expensive work (elem.offsetWidth) after evaluating the parts that don't trigger a reflow? In the case the element is determined to be hidden by the style, it does not trigger a reflow anymore, what would be a nice behavior for a hidden element. \ \ So instead of \ {{{ \ return ( elem.offsetWidth === 0 && elem.offsetHeight === 0 ) \|\| (!jQuery.support.reliableHiddenOffsets && ((elem.style && elem.style.display) \|\| curCSS( elem, "display" )) === "none"); \ }}} \ do \ {{{ \ return (!jQuery.support.reliableHiddenOffsets && ((elem.style && elem.style.display) \|\| curCSS( elem, "display" )) === "none") \|\| ( elem.offsetWidth === 0 && elem.offsetHeight === 0 ); \ }}} \ Roel
milestone:	None → 1.9
priority:	undecided → low
status:	new → open

Changed November 12, 2012 04:48PM UTC by timmywil comment:2

I'm fine with it, but isn't display calculation a lot more expensive in IE than .offsetWidth/.offsetHeight?

Changed November 12, 2012 05:01PM UTC by dmethvin comment:3

I think display just looks at the property for that element so no recalc should be required. The offset properties definitely require a recalc if one hasn't already been done, I'm always seeing big delays on offsetWidth/Height in profile runs for IE.

Changed November 12, 2012 06:36PM UTC by r.spilker@gmail.com comment:4

Created pull request: https://github.com/jquery/jquery/pull/1027

Changed November 12, 2012 07:25PM UTC by timmywil comment:5

@dmethvin: I'm wondering, is offsetWidth/Height faster even when the codepath hits defaultDisplay? But even if it is, this is probably a better way to go.

Changed November 26, 2012 05:33PM UTC by timmywil comment:6

owner:	→ timmywil
status:	open → assigned
version:	git → 1.8.3

Will create a perf

Changed December 12, 2012 04:14PM UTC by dmethvin comment:7

resolution:	→ notabug
status:	assigned → closed

Based on the perf we decided not to land this.

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#12885 closed feature (notabug)