Accessing inherited behavior properties

Hello,

I've created a new extender who's behavior class in the javascript file inherits from an existing control (in this case the cascading drop down) and registered it like so:

CustomCascadingDropDown.CustomCascadingDropDownBehavior.registerClass(
'CustomCascadingDropDown.CustomCascadingDropDownBehavior', AjaxControlToolkit.CascadingDropDownBehavior
);

I'm listening for the selectedValue property change event to occur so that I can access the resulting value and operate on it but when I try to access it from my inherited behavior class as this._selectedValue I get a null value. If I try using the callBaseMethod method to access the property accessor I get a different exception. How do I access inherited properties?

Also, what is the correct procedure for attaching to property changed events? I assumed from other posts that is by using this.add_propertyChanged(handler) but is this correct? How does this attach itself to a specific property or does it just enumerate through all properties that have been changed?

Thanks in advance.

Hi,

can I see the code that you're using to handle the event?

Sure thing... thanks for the help by the way.

The code below is just a test. I just want to see if I can access the inherited property.

First I attach a handler to listen for the property changed event in the initialize method of my custom behavior:

initialize : function() {
PersistentCascadingDropDown.PersistentCascadingDropDownBehavior.callBaseMethod(this, 'initialize');
this.add_propertyChanged(this.test);
},

Again, I'm not sure if this is the correct way to attach a handler to the propertyChanged event. It is only an assumption (how exactly do I target only one of the many properties that raise propertyChanged events?).

Next is my event handling method.

test : function (sender, args)
{
if (args._propertyName == "SelectedValue")
{
// Throws an exception
alert(PersistentCascadingDropDown.PersistentCascadingDropDownBehavior.callBaseMethod(this, 'get_SelectedValue'));

// Alerts as undefined
alert(typeof(this.get_SelectedValue));

// Alerts that object doesn't support method
alert(this.get_SelectedValue());
}
},

Thanks again for your help.