Implementing the event mechanism

About this task

Do the following steps to implement the event mechanism:

  1. Define the event handler in widget Java script:
    this.handler1 = function() {	
    		 alert(‘handler1');
    }
  2. Listen the event in widget using one of the following methods:
    1. Code directly.
      this.iContext.addEventListener('eventName1',false, this.handler1,this);
      BTT Web 2.0 provides multiple parameters for you to listen events.
      Table 1. Listen event
      API Input Output
      this.iContext.addEventListener P1,P2, P3,…Pn P1 is the event id. P2 is a flag that decides whether this event can be subscribed by other widgets. True denotes that this event you listen is private and you cannot receive this event, but false means the event is public and this widget can listen and receive it. P3 is the handler for this listener. P4 is the scope and normally we use ‘this' for this widget, and P5…Pn are the input parameter of handler
    2. :Configured in .xml file.
      You also can declare the event in widget definition XML file:
      ......
        <iw:event id="eventName1" onEvent="handler1 " isPrivate=”false” />
        <iw:content mode="view">
        </iw:content>
      
      </iw:iwidget>
  3. Invoke the event:
    this.iContext.fireEvent('eventName1', false);	
    BTT Web 2.0 provides multiple parameters for you to fire event:
    Table 2. Fire event
    API Input Output
    this.iContext.fireEvent P1,P2, P3,…Pn P1 is the event id. P2 is a flag that decides whether this event can be subscribed by other widgets. True denotes that this event is private, but false means the event is public and other widgets can listen it.P3…Pn are the input parameter of handler