domNode.isConnected is a flag which is available in chrome. It shows whether domNode is part of the document.
Is it cross browser patible?
If not is there any efficient alternative for this for other browsers? Please provide link for any available documentation.

domNode.isConnected is a flag which is available in chrome. It shows whether domNode is part of the document.
Is it cross browser patible?
If not is there any efficient alternative for this for other browsers? Please provide link for any available documentation.

• javascript
• jquery
• dom

• 1 This sounds a little like an X/Y problem. Could you describe why you need to know whether an element is already part of the DOM, as there may be a better way to achieve what you need. – Rory McCrossan Commented Jun 2, 2016 at 10:00
• There are various ways to know if a node is part of the dom. But this I found most efficient as it requires no traversal. I just want know more about this and I cant find any thing about it anywhere. – rishabh dev Commented Jun 2, 2016 at 10:03
• 1 Brief but docs here - dom.spec.whatwg/#dom-node-isconnected – Praveen Puglia Commented Jun 2, 2016 at 10:20

3 Answers 3

It is not supported, but very easy to polyfill.

(function (supported){
  if (supported) return;
  Object.defineProperty(window.Node.prototype, 'isConnected', {get})
  function get() {
    return document.contains(this);
  }
})('isConnected' in window.Node.prototype);

A quick test shows Firefox doesn't support this property. So the answer is no.

var input = document.getElementById('input');
alert(input.isConnected);

<input type="text" id="input">

https://jsfiddle/hu08awn0/

This is a full node.isConnected polyfill that I wrote for IE & EdgeHTML:

if (!('isConnected' in Node.prototype)) {
  Object.defineProperty(Node.prototype, 'isConnected', {
    get() {
      return (
        !this.ownerDocument ||
        !(
          this.ownerDocument.pareDocumentPosition(this) &
          this.DOCUMENT_POSITION_DISCONNECTED
        )
      );
    },
  });
}