Simple event generation

In an effort to keep each chapter and its included code samples as relevent as possible to the context around it, I decided that a toolkit made the most sense. I also decided to simple write the toolkit and include it for the following reasons:

1. I haven't used any of the ones out there yet for long enough to use them to correctly accomplish exactly what I need without coding the samples specifically for that particular toolkit.
2. I needed a toolkit anyway for other things I work on and (since I'll release this under the BSD License), I can write it and use it anywhere.
3. The toolkit will only need to cover a comparatively limited set of features, so I won't re-write all of Dojo, for example.
4. Incuding code samples like the following reinforce the overall method of development.

The following implements very simple, yet effective, event listening. Just extend the EventDispatcher with whatever object has events (form handlers save, fail, delete, load, clear, etc.) and extend the CustomEvent object to fit your needs. This gets used extensively throughout the book in order to simplify the objects through encapsulation.

function CustomEvent() { }
CustomEvent.prototype = {
 type : 'custom'
}

// Custom EventTarget equivalent
function EventDispatcher() { }
EventDispatcher.prototype = {
 // An object literal to store arrays of listeners by type
 events : {},
 
 // If it supports the type, add the listener (capture ignored)
 addEventListener : function(type, listener, capture) {
  if (this.events[type]) {
   this.events[type].push(listener);
  }
 },
 
 // If it supports the type, remove the listener (capture ignored)
 removeEventListener : function(type, listener, capture) {
  if (this.events[type] == undefined) {
   return;
  }
  var index = this.events[type].indexOf(listener);
  if (this.events[type][index]) {
   this.events[type].splice(index, 1);
  }
 },
 
 // Cycle through all of the event listeners, passing the event to the callbacks
 dispatchEvent : function(type, event) {
  if (this.events[type]) {
   for (var i in this.events[type]) {
    this.events[type][i](event);
   }
  }
 }
}

Edited so you can read the code.

12/8/06 - Edited to fix dispatchEvent to actually work.