var Events = {
	// Add event handler to data source
	addToDocumentEvent: function( eventName:String, expression:String, dataSourceId:String ){
		try {			
			if( expression.indexOf( 'javascript:' ) === -1 ){
				expression = '#{javascript:' + expression + '}';				
			}
	
			var dataSource = this.getDataSource( dataSourceId );
	
			var capitalizedEventName = eventName.replace( /^\w/, eventName.substring( 0,1 ).toUpperCase() );
			
			// If the event handler is from the page, add to queue
			var previousEventHandler:javax.faces.el.MethodBinding = dataSource[ 'get' + capitalizedEventName ]();
			
			// If event handler exists
			if( typeof previousEventHandler === 'com.ibm.xsp.binding.javascript.JavaScriptMethodBinding' ){
				var previousExpression = previousEventHandler.getExpressionString();
				
				// Event came from page
				if( previousExpression.indexOf( 'Events.runEventQueue' ) === -1 ){
					this.setInitialPageEvent( capitalizedEventName, previousEventHandler );
				}				
			}	
								
			/* 
				If the page doesn't have an existing event handler, or the event handler is from the page
				- add handler that runs all queued events
			*/ 
			var application = facesContext.getApplication();
			if( !previousExpression || 
				( previousExpression && previousExpression.indexOf( 'Events.runEventQueue' ) === -1 ) ){				
				var queueRunnerEvent = application.createMethodBinding( 
					'#{javascript:Events.runEventQueue( "' + capitalizedEventName + '" );}', null );
					
				dataSource[ 'set' + capitalizedEventName ]( queueRunnerEvent );
			}
			
			// Add event handler from expression-parameter			
			var eventHandler = application.createMethodBinding( expression, null );
			this.addEventToQueue( capitalizedEventName, eventHandler );
						
		} catch( e ){
			if( Debug ){ Debug.exception( e ); }
		}
	},
	
	// Get the data source - If dataSourceId isn't specified, get first document data source
	getDataSource: function( dataSourceId ){
		try {			
			var dataSource, dataSources:java.util.ArrayList = view.getData();	
			for( var i = 0; i < dataSources.size(); i++ ){
				dataSource = dataSources.get( i );
				if( dataSourceId ){
					if( dataSource.getBeanId().indexOf( '|' + dataSourceId ) > -1 ){ break; }
				} else {
					if( dataSource.getClass().getName() === 'com.ibm.xsp.model.domino.DominoDocumentData' ){
						break;
					}
				}
			}		
		} catch( e ){ Debug.exception( e ); }
		
		if( !dataSource ){
			if( dataSourceId ){
				throw new java.lang.Exception( 'Unknown data source, "' + dataSourceId + '"' );
			}
		}
		
		return dataSource;
	},
	
	
	addEventToQueue: function( capitalizedEventName, eventHandlers:java.util.ArrayList ){
		var queuedEvents:java.util.ArrayList = this.getQueue();
		queuedEvents.add( eventHandler );
		this.setQueue( capitalizedEventName, queuedEvents );
	},
	
	setInitialPageEvent: function( capitalizedEventName, eventHandler:javax.faces.el.MethodBinding ){
		try {
			viewScope.put( 'initial' + capitalizedEventName, eventHandler );	
		} catch( e ){ Debug.exception( e ); }
		
	},
	
	getInitialPageEvent: function( capitalizedEventName ){
		try {
			return viewScope.get( 'initial' + capitalizedEventName );
		} catch( e ){ Debug.exception( e ); }
	},
	
	
	setQueue: function( capitalizedEventName, eventHandlers:java.util.ArrayList ){
		try{	
			viewScope.put( 'queued' + capitalizedEventName + 's', eventHandlers );
		} catch( e ){ Debug.exception( e ); }
	},
	
	// Returns java.util.ArrayList<javax.faces.el.MethodBinding> 
	getQueue: function( capitalizedEventName ){
		try{		
			var eventHandlers = viewScope.get( 'queued' + capitalizedEventName + 's' );
			if( !eventHandlers ){
				viewScope.put( 'queued' + capitalizedEventName + 's', new java.util.ArrayList() );
			}
			
			return viewScope.get( 'queued' + capitalizedEventName + 's' );
		} catch( e ){ Debug.exception( e ); }
			
	},
	runEventQueue: function( capitalizedEventName ){
		try{
			var eventHandlers:java.util.ArrayList = this.getQueue( capitalizedEventName );
			
			// Run the initial page event at the end
			var initialPageEvent = this.getInitialPageEvent( capitalizedEventName );
			if( initialPageEvent ){			
				var eventResult = initialPageEvent.invoke( facesContext, null );
				
				if( eventResult === false ){ // Exit - initial page event halted				 
					return;	
				}
			}
			
			if( eventHandlers.size() > 0 ){			
				// Runs all queued event handlers for the event
				var eventHandler;
				for( var i = 0; i < eventHandlers.size(); i++ ){				
					eventHandler = eventHandlers[i];
					eventHandler.invoke( facesContext, null ); 
				}
		 	}
		} catch( e ){ Debug.exception( e ); }
	}
}


// Helper-class for debugging
var Debug = {	
	// Send a stack trace of an exception
	exception: function( exception ){
		var stringWriter = new java.io.StringWriter();
		exception.printStackTrace( new java.io.PrintWriter( stringWriter ) );
		this.message( stringWriter.toString(), 'Exception!' );
	},
	// Send a message
	message: function( message, subject ){
		var doc:NotesDocument = database.createDocument();
		doc.replaceItemValue( 'Form', 'Memo' );
		doc.replaceItemValue( 'Subject', subject || 'Debug..' );
		doc.replaceItemValue( 'Body', message.toString() );
		doc.replaceItemValue( 'SendTo', @Name( '[CN]', @UserName() )  );
		doc.send()
	}
};