• Global variables are evil. Create a "module" for an application that can house all of its members. The YAHOO namespace function is a good way to create a module for a YUI application.

   YAHOO.namespace("my");

• Most widgets fire low-level events. An application should create a set of "idiomatic" events to represent the steps from its own use cases. Event handling can be centralized in the application module.

   YAHOO.my.events.onEntryListReturn = function(oData) {
     YAHOO.log("entryList Event");
     YAHOO.my.events.fireEvent("entryList", oData);
   } 

• Simple widgets are simple to construct, but constructing composite widgets can be complex. Represent composite widgets as a "Crockford singleton" and provide a "power constructor" to configure and augment composite widgets.

   YAHOO.my.PhoneBook = function() {
     var phonebook = object(FlevBase);                  
     phonebook.oColumnHeaders = [
   
     // ...

• Composite widgets (say, a DataForm, DataView, and TabView) can often be reused either within an application or between applications. Create a base object that can be used as template for other objects, and configured by a power constructor.

   var FlevBase = function() {
     // define private members (none)
     // return public members
     return {        
        oColumnHeaders: null,        
        oConfigs: null,
        // ...
        load: function(oData,oSelf) {
       // ...
          oSelf.oColumnSet = new
YAHOO.widget.ColumnSet(oSelf.oColumnHeaders);

The PhoneBook example application uses this module/events/singletons approach to deploy a FLEV widget.

• HTML page
• Page Script
• FLEV script