javascript - Remove an event listener from a component only based off of its function name - Ext Js -

alright have viewport divided 2 halves, top , bottom. top half has combo boxes , input fields visible, bottom half has tab panel multiple tabs.

when change 1 of static combo boxes on top half, i'll call combo box a, fires event , in event handler, a_handler, attempt style combo box in 1 of tabs, i'll call combo box b, may 1 of 2 things.

combo box b visible on tab 2, not 1.

so then:

1) if tab 1 active, setup event handler style combo box b when tab 2 made active.

2) otherwise, style it.

so here's problem: initial combo box, a, can style combo box b 1 of 2 possible ways, depending on selection, red , blue.

so imagine situation tab 1 visible, , select option style b red, event handler created when tab 2 activated. then, without activating tab 2, change option again in combo a, make box b blue.

at point, need remove first event handler 1 fired.

i not have reference event handlers, have named them.

i have created functions acquire list of event listeners on tab 2, , know name of listener remove, can match names, scopes not same when attempt remove them tab's removelistener, nothing happens.

solved

eventually found solution this.

the un or removelistener functions setup this:

un( eventname, fn, [scope] )

my problem did not have reference specific handler pass in fn

the solution involves finding fn ref searching fn name.

so when event listener created, setup name:

mytab.on('activate', function dosomestuff() {

later on when need check if exists/possibly remove it:

objecthasnamedlistener: function(obj, eventtype, name) {   var listeners = obj.events[eventtype].listeners;    //trim functionality since .trim() doesn't exist in old ie   name = name.replace(/^\s+|\s+$/g, '');    if (listeners != undefined) {      (var = 0; < listeners.length; i++) {         var func = listeners[i].fn;         var funcstr = func.tostring();         var funcname = funcstr.substr('function'.length);         funcname = funcname.substr(0, funcname.indexof('('));         funcname = funcname.replace(/^\s+|\s+$/g, '');         if (funcname == name) {            return true;         }      }   }   return false; }, 

and if returns true, reference handler:

if (this.objecthasnamedlistener(mytab, "activate", "dosomestuff")) {     var listener = this.getnamedlistener(mytab, "activate", "dosomestuff");     mytab.removelistener("activate", listener, this); }     getnamedlistener: function(obj, eventtype, name) {     var listeners = obj.events[eventtype].listeners;      name = name.replace(/^\s+|\s+$/g, '');      if (listeners != undefined) {        (var = 0; < listeners.length; i++) {           var func = listeners[i].fn;           var funcstr = func.tostring();           var funcname = funcstr.substr('function'.length);           funcname = funcname.substr(0, funcname.indexof('('));           funcname = funcname.replace(/^\s+|\s+$/g, '');            if (funcname == name) {              return func;           }        }     }      return null;   }, 

the other caveat listener had created , removed same scope passed in, despite fact listed [optional] in api, passing in worked fine