Some code I am working with replaces some HTML elements that have Dojo event listeners with new HTML ing from an AJAX call (using .innerHTML=). I have read that event listeners should be disconnected using the dojo.disconnect(handle) method before they are replaced to prevent memory leaks.

Is it possible to derive all handles connected to a particular element, so that I can pass each one to .disconnect(handle), or is it up to me to maintain this list in my code?

Some code I am working with replaces some HTML elements that have Dojo event listeners with new HTML ing from an AJAX call (using .innerHTML=). I have read that event listeners should be disconnected using the dojo.disconnect(handle) method before they are replaced to prevent memory leaks.

Is it possible to derive all handles connected to a particular element, so that I can pass each one to .disconnect(handle), or is it up to me to maintain this list in my code?

• javascript
• memory-leaks
• dojo

Share Improve this question Follow asked May 15, 2009 at 20:36 AndreiMAndreiM 4,59844 gold badges3838 silver badges5050 bronze badges

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2 Answers 2

Sorted by: Reset to default 5

Actually if you are using widgets they normally should disconnect stuff in tehir destroy() method. If you are handling the nodes yourself, I see two ways you can go.

1) Manage all connects manually, means storing them somewhere. 2) Probably the safer one: store all the connect handlers in the node they connect to, like so:

node._connectHandlers = [];
node._connectHandlers.push(dojo.connect(node, "onclick", ...));

And later you can simply disconnect them all using

dojo.query("*", nodeContainingConnects).forEach(function(node){
    if (typeof node._connectHandlers!="undefined"){
        dojo.forEach(node._connectHandlers, "dojo.disconnect(item)");
    }
});

Actually, this may work well, but there might be a more efficient way to get all connects by nodes. I just didnt find it. hth

Following the answer of Wolfram Kriesing this can be "improved":

dojo._connect_tmp = dojo.connect;
dojo.connect = function (obj, event, context, method, dontFix) {
    if(obj._connectHandlers == undefined){ obj._connectHandlers = [];}
    var handler = dojo._connect_tmp (obj, event, context, method, dontFix);
    obj._connectHandlers.push(handler);
    return handler;
};

dojo.iwanttobefree = function (obj) {
   if(obj._connectHandlers == undefined) {
   } else {
      dojo.forEach(obj._connectHandlers, "dojo.disconnect(item)");  
   }
};

Then you can do this:

dojo.connect(myObj, 'onfocus', function(){alert('weee')});
dojo.iwanttobefree(myObj);

Replacing dojo code can be very very very ugly for multiple reasons, so maybe you want to create your own namespace.