[EDGE CASE / ANTIPATTERN] Remove observer error

[mrichard1]

Hi,

I report to you a bug when I try to remove a mediator, the observers result is null in the View class and removeObserver method.

This is normal in my case that the return value is null because I update dynamically the listNotificationInterests in the mediator and one of these was not registered. (I remove and insert it to update this list )


I propose a solution to put in the removeObserver method ,

if( !observers ){ //correct null error
   return ;
}

Thanks.

Best regards,
Marc

[puremvc]

Dynamically messing with the observer lists is not a best practice. The framework maintains those lists. This is why Mediators are interrogated for their interests at registration time.

If you change the interests of a Mediator dynamically, then you MUST have its listNotificationInterests method return the *current* interests (NOT the initial interests) at removal time. If you do this, your problem will not occur.

If ths had come in yesterday, I would've included it in the 2.0.4 release.

Filed under edge-case anti-pattern with workaround for now.

-=Cliff>