Bug Tracker

Opened 14 years ago

Closed 12 years ago

Last modified 11 years ago

#4345 closed feature (fixed)

add isDescendantOf and isAncestorOf

Reported by: ap Owned by:
Priority: low Milestone:
Component: selector Version: 1.3.2
Keywords: Cc:
Blocked by: Blocking:


It would be handy to test if an element is a parent/child of another element. This is particularly useful when handling event bubbling to determine if an event has already been handled (this is the most reliable technique I have found to date that works in most modern browsers).

I expect it would look something like this:

jQuery('#blah').isAncestorOf(someElement) and jQuery('#blah').isDescendantOf(someElement)

Alternatively but less accurately it could be called isParentOf/isChildOf.

My existing JS implementation runs in logarithmic time and is as follows:

/ test if a is a descendant of b */ function isDescendantOf(a, b) {

return isAncestorOf(b, a);


/ test if a is an ancestor of b */ function isAncestorOf(a, b) {

test if a is in b's parent chain var o = b; while (o) {

if (o === a)

return true;

o = o.parentNode; }

return false;


Having this as part of jQuery would be convenient.

Change History (4)

comment:1 Changed 14 years ago by dmethvin

Related to #4101.

comment:3 Changed 12 years ago by Rick Waldron

Component: coreselector
Keywords: needsreview added; isancestor isancestorof isdescendant isdescendantof ischild ischildof isparent isparentof removed
Milestone: 1.4
Priority: minorlow
Status: newopen

Bringing this back for review

comment:4 Changed 12 years ago by dmethvin

Keywords: needsreview removed
Resolution: fixed
Status: openclosed
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