Adobe 0046100128056 - InDesign - Mac - Working with Event Listeners

CHAPTER 8: Events Working with Event Listeners 119
triggering any qualifying eventListeners registered to objects above the target in the scripting
object model hierarchy.
The following table provides more detail on the properties of an event and the ways in which they relate
to event propagation through the scripting object model.
Working with Event Listeners
When you create an eventListener, you specify the event type and the event handler (as a function or
file reference). The following script fragment shows how to add an
eventListener for a specific event (for
the complete script, see AddEventListener).
var myEventListener = app.addEventListener("afterNew", myDisplayEventType, false);
The preceding script fragment refers to the following function:
function myDisplayEventType(myEvent){
alert("This event is the " + myEvent.eventType + " event.");
}
To remove the eventListener created by the preceding script, run the following script (from the
RemoveEventListener tutorial script):
app.removeEventListener("afterNew", myDisplayEventType);
When an eventListener responds to an event, the event may still be processed by other
eventListeners that might be monitoring the event (depending on the propagation of the event). For
example, the
afterOpen event can be observed by eventListeners associated with both the application
and the document.
Property Description
Bubbles
If true, the event propagates to scripting objects above the object initiating
the
event.
Cancelable
If true, the default behavior of the event on its target can be canceled. To do
this, use the
PreventDefault method .
CurrentTarget
The current scripting object processing the event. See target in this table.
DefaultPrevented
If true, the default behavior of the event on the current target was
prevented, thereby canceling the action. See
target in this table.
EventPhase
The current stage of the event propagation process.
EventType
The type of the event, as a string (for example, "beforeNew").
PropagationStopped
If true, the event has stopped propagating beyond the current target (see
target in this table). To stop event propagation, use the stopPropagation
method .
Target
The object from which the event originates. For example, the target of a
beforeImport event is a document; of a beforeNew event, the application.
TimeStamp
The time and date when the event occurred.