PureMVC学习(二)

Command与Mediator和Proxy交互，应避免Mediator与Proxy直接交互。看下面一个用于程序"启动"的Command:

package com.wf.controller
{
	import org.puremvc.as3.core.Model;
	import org.puremvc.as3.patterns.command.MacroCommand;

	/**
	 * 程序开始时执行的MacroCommand
	 */ 
	public class StartupCommand extends MacroCommand
	{
		/**
		 * 添加子Command初始化MacroCommand
		 */ 
		override protected function initializeMacroCommand():void
		{
			addSubCommand(ModelPrepCommmand);
			addSubCommand(ViewPrepCommand);
		}
	}
}

这是一个添加了两个子Command的MacroCommand.执行时，两个子命令会按照FIFO的顺序被执行。

一般，开启(startup)主要有两个过程：Model初始化与View初始化。

package com.wf.controller
{
	import org.puremvc.as3.interfaces.INotification;
	import org.puremvc.as3.patterns.command.SimpleCommand;

	//创建Proxy对象，并注册
	public class ModelPrepCommand extends SimpleCommand
	{
		//由MacroConmmand调用
		override public function execute(notification:INotification):void
		{
			facade.registerProxy(new SearchProxy());
			facade.registerProxy(new PrefsProxy());
			facade.registerProxy(new UserProxy());
		}
	}
}

Command并没有操作或初始化任何的Model数据.Proxy的职责才是取得、创建 和初始化数据对象。

package com.wf.controller
{
	import mx.core.Application;
	
	import org.puremvc.as3.interfaces.INotification;
	import org.puremvc.as3.patterns.command.SimpleCommand;

	//创建Mediator,并把他们注册到View
	public class ViewPrepCommand extends SimpleCommand
	{
		override public function execute(notification:INotification):void
		{
			var app:PureMvcStudy = notification.getBody() as PureMvcStudy;
			facade.registerMediator(new ApplicationMediator(app));
		}
	}
}