Optimisation - delegate to $.has for calls to $.closest whicgh are passed a node/jQuery rather than a selector

[wheresrhys]

While trying to optimise a bit of code I came across the surprising fact that

jQueryInstance.has(DOMnode)

is 2-3 times as fast as

$(DOMnode).closest(jQueryInstance/DOMnode)

​http://jsperf.com/efficient-way-to-find-elements-not-contained-in-another

Could this be used within $.fn.closest to optimise it when a node/jQuery is passed in rather than a selector -

if(typeof selector !== "string) {
   return $.fn.has.call(selector, this);
}

[dmethvin]

Is that a common case? Do you have an app that is slow because of it? If it's not a bottleneck in real code, it's hard to justify a special case. It makes the code bigger, more complex, and harder to test.

[wheresrhys]

Couldn't really comment on whether it's a common use case to get the closest node which is a specific node. My use case was in order to exclude matches from within a given node (e.g get all inputs in a page which aren't in a specific form), but then again, for this case direct use of $.has within the $.filter function is available

[ajpiano]

You can also use jQuery.contains when you are trying to do that check and you have access to actual nodes for the container and containing elements.

[addyosmani]

This is looking like a special case to me and as Adam pointed out jQuery.contains could be used for this particular case. @dmethvin do you think there's enough justification to keep this open?

[dmethvin]

Doesn't seem common enough to add IMO. If someone has some real-life code that is made much happier by this let us know.