addValueChangeListener getting called two times all the time

Hi Experts,

For one of my portlet i have used the addValueChangeListener listener and when value changes , it gets called two times all the time . Is there a way we could restrict this to once ?

Regards,
Nischal

Hi Nischal,

We had a similar problem also.

Basically every time he page was refreshed a new listener was added, thus determining the action that is triggered by the listener to be executed multiple time.

What we did is to check if a listener with the same name already exists before adding it.

The code looks like this (and it is placed in a Script block on the page):


var toggleTabs = CAF.model("#{caf:cid('toggleTabs')}");
var booleanFlag= false;
if(toggleTabs){
	for (var i = 0, l, listeners = toggleTabs.listValueChangeListeners(); l = listeners[i]; i++){
		if(l.key.name=='myMethodThatDoesSomething'){
			booleanFlag = true;
		}
	}
	if(!booleanFlag){
 	 	toggleTabs.addValueChangeListener(myMethodThatDoesSomething); 		
	}
}

function myMethodThatDoesSomething(){
    //your desired code here
}

Also you can use Firebug or other similar tools (maybe Developer Tools- F12 if you are using IE) to check the listeners and other element attributes.

Hope it helps,
Vlad Turian

Hi Vlad,

I tried with the approach you have mentioned , but somehow when i go over the browser console i see that it states TypeError: togglebutton.listValueChangeListeners is not a function . Could you please let me know if i miss something here ?

Thank you in advancne.

Regards,
Nis

Hi Nischal,

For what element do you try to use the listValueChangeListeners?

I am using it successfully for (com.webmethods.caf.faces.component.toggle.html.)HtmlToggleTabs.

Please check the 8-2-SP1_CAF_JavaScript_Reference to see if this javascript function is available for your desired element.

At a first sight it seems that the element has to inherit from CAF.Input.Model to have the listValueChangeListeners.

Hope it helps,
Vlad Turian