Add NodeList.destroy

[Eugene Lazutkin]

This ticket is created from Les' remark in #10827:

This is something I don't understand about Dojo. If I destroy a widget or remove a DOM element, all event event handlers bound to that widget or DOM element should be unbound. I shouldn't have to worry about it.

See the jQuery doc for the remove() method. They unbound event handlers, but dojo.orphan() is not doing that.

​http://api.jquery.com/remove/

[Eugene Lazutkin]

One possible solution is to add destroy() (as in dojo.destroy) to our NodeList --- NodeList.orphan() does nothing to prevent leaks. In the same vein we lack NodeList.removeAttr() and some other useful helpers.

Obviously we should augment dojo.destroy() code too, if it leaks.

[Terence Kent]

/bump

I'm just starting out with dojo and ran into this right away. An easy way to illustrate the leak is to create some large number of dom nodes inside of some container (say 1000), and attach some anonymous function as an event handler to each dom node using dojo.connect.

Then, remove all the DOM nodes in the container using dojo.empty. Rinse and repeat.

You won't see a leak with a good browser (e.g. FireFox? 2, Chrome, or Safari) but bring in everybody's favorite IE (v. 6) and it's clearly apparent.

The issue can also easily be solved by tracking all the handles returned from dojo.connect calls and then using dojo.disconnect to remove the event listeners before calling dojo.empty. When the events are disconnected prior to an dojo.empty() call, no leak occurs. Would be great if dojo behaved like jQuery in this instance and managed this clean up for us measly developers.

[bill]

Not sure if this is still an issue or not, or who it should be assigned to... #10827 is resolved, as is #13065, but it looks like this ticket is really about adding a NodeList.destroy() method.

[dylan]

Renaming given that the main issue of the original ticket was closed elsewhere. Marking this enhancement as patchwelcome.