CODEWITHSUNDEEP
javascriptdomobjectself-destruction
RSilva
RSilva

Reputation: 6943

How can a object self destruct on an event, in javascript?

I have this function, to create a DIV on-the-fly. But now, I want to destroy this object on onclick event, but I just don't know how.

function creatediv(id) {

    var newdiv = document.createElement('div');
    newdiv.setAttribute('id', id);
    newdiv.onclick=function(){this=null;};  //bad function
    document.body.appendChild(newdiv);

}

What am I missing?

Thanks

Upvotes: 6

Views: 7874

Answers (3)

Chetan S
Chetan S

Reputation: 23813

Just setting it null will not destroy it. You need to remove it from the document tree while making sure there are no references pointing to it.

function creatediv(id) {
    var newdiv = document.createElement('div');
    newdiv.setAttribute('id', id);
    newdiv.onclick=function(e) {
        this.parentNode.removeChild(this);
    };  
    document.body.appendChild(newdiv);
    newdiv = null;//required in IE to prevent memory leak
}

Upvotes: 11

KooiInc
KooiInc

Reputation: 122936

The accepted answer seems wrong to me. First, it doesn't consider newdiv containing childnodes, so the suggested remove routine maintains a danger for memory leaks via closures (IE). Second, because of the position of 'newdiv = null' the creatediv function immediately destroys the just created element. I would recommend using Douglas Crockfords purge function for the click handler, substituting d with this.

function purge(d) {
    var a = d.attributes, i, l, n;
    if (a) {
        l = a.length;
        for (i = 0; i < l; i += 1) {
            n = a[i].name;
            if (typeof d[n] === 'function') {
                d[n] = null;
            }
        }
    }
    a = d.childNodes;
    if (a) {
        l = a.length;
        for (i = 0; i < l; i += 1) {
            purge(d.childNodes[i]);
        }
    }
}

Upvotes: 5

Chris Ballance
Chris Ballance

Reputation: 34347

function removeElement(divNum) {
  var d = document.getElementById('myDiv');
  var olddiv = document.getElementById(divNum);
  d.removeChild(olddiv);
}

Upvotes: 0

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