Events
In Ext JS events are signals from a class that are fired if anything happened
to a class. Events are fired globally in the Ext namespace so that every class
can listen to those. In our Ext JS application we can use these events to code
specific reponses that will be executed if a certain event is being fired. Nearly
all Ext JS components and classes fire different kinds of events at their
lifecycle. For example, each class inherited from Ext.Component fires the
event added after the component had been added to a container. We can listen
for that event by configuring a simple listeners object.
In this section we'll get to know three events fired by different components to
get a basic idea about the potential behind events and listeners.