How to find with javascript if element exists in DOM or it's virtual (has been just created by createElement) -

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i'm looking way find if element referenced in javascript has been inserted in document.

lets illustrate case following code: 

var elem = document.createelement('div');  // element has not been inserted in document, i.e. not present  document.getelementbytagname('body')[0].appendchild(elem);  // element can found in dom tree

jquery has :visible selector, won't give accurate result when need find invisible element has been placed somewhere in document.

here's easier method uses standard node.contains dom api check in element in dom:

document.body.contains(my_element);

cross-browser note: document object in ie not have contains() method - ensure cross-browser compatibility, use document.body.contains() instead. (or document.head.contains if you're checking elements link, script, etc)

 

 

notes on using specific document reference vs node-level ownerdocument:

someone raised idea of using my_element.ownerdocument.contains(my_element) check node's presence in document. while can produce intended result (albeit, more verbosity necessary in 99% of cases), can lead unexpected results, depending on use-case. let's talk why:

if dealing node resides in separate document, 1 generated document.implementation.createhtmldocument(), <iframe> document, or html import document, , use node's ownerdocument property check presence in think main, visually rendered document, in world of hurt.

the node property ownerdocument pointer whatever current document node resides in. every use-case of contains involves checking specific document node's presence. have 0 guarantee ownerdocument same document want check - know that. danger of ownerdocument may introduce number of ways reference, import, or generate nodes reside in other documents. if so, , have written code rely on ownerdocument's relative inference, code may break. ensure code produces expected results, should compare against specifically referenced document intend check, not trust relative inferences ownerdocument.


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