topic Re: Disconnecting Events and Handlers in ArcGIS JavaScript Maps SDK Questions

Disconnecting Events and Handlers

SunilPalkar — Mon, 22 Oct 2012 11:58:47 GMT

Hello All,

Good Morning,

I am new one to JSAPI . Its regarding to events and handlers.

I read some wherever that you need to disconnects events to avoid memory leaks. Is it necessary because in my sample application I am using lots of events on mouse move ,mouse click etc.

So any help with proper explanation will be great !!

Re: Disconnecting Events and Handlers

__Rich_ — Mon, 22 Oct 2012 14:25:38 GMT

dojo.disconnect

Re: Disconnecting Events and Handlers

SunilPalkar — Tue, 23 Oct 2012 03:58:31 GMT

Thanks for your reply....but is it essential ?? because I have used this in my application and not able to see the big difference after using this..

dojo.disconnect

Re: Disconnecting Events and Handlers

StephenLead — Sun, 12 Dec 2021 03:59:22 GMT

Thanks for your reply....but is it essential ?? because I have used this in my application and not able to see the big difference after using this..

Try something like this:


//Run this code to start the listener
listener = dojo.connect(layer,"onMouseOver",function(evt){
  //do something on hover
}
//run this code to disconnect the listener
dojo.disconnect(listener)

Re: Disconnecting Events and Handlers

BenFousek — Thu, 25 Oct 2012 14:38:02 GMT

You don't need to worry about memory leaks on page unload from event handlers. Javascript frameworks like dojo and jquery do clean up, including removal of event handlers, when the page unloads.

Of greater concern is performance of the application while it's running. Asynchronous web apps can use up a lot of memory fast. https://developers.google.com/speed/articles/optimizing-javascript Check this out for ways to improve performance and avoid coding that may cause memory leaks.