Micro Architecture ─ PureMVC Part2

把之前的補完，先介紹一下Mediator

Mediator用來管理可見元件，讓原本UI能與PureMVC溝通，主要負責觸發跟反應Notification

ApplicationMediator

package idv.gd.pureMVCTest.view
{
        import flash.events.MouseEvent;
        
        import idv.gd.pureMVCTest.ApplicationFacade;
        
        import org.puremvc.as3.interfaces.INotification;
        import org.puremvc.as3.patterns.mediator.Mediator;
        
        public class ApplicationMediator extends Mediator
        {               
                public static const NAME:String = "ApplicationMediator";        
                
                public function ApplicationMediator(viewComponent:Main)
                {
                        super(NAME, viewComponent);             
                }
                
                /**
                 * view內所有的元件註冊在此
                 */
                override public function onRegister():void
                {                               
                        super.onRegister();
                        
                        facade.registerMediator(new RSSReaderMediator(main.reader));
                        
                        main.newsBtn.addEventListener(MouseEvent.CLICK, getNewsHandler);
                        main.techBtn.addEventListener(MouseEvent.CLICK, getTechHandler);                        
                }       
                
                private function getNewsHandler(event:MouseEvent):void
                {
                        facade.sendNotification(ApplicationFacade.READ_NEWS);
                }
                
                private function getTechHandler(event:MouseEvent):void
                {
                        facade.sendNotification(ApplicationFacade.READ_TECH);
                }
                
                protected function get main():Main
                {
                        return viewComponent as Main;
                }
     }
}

Mediator會對應到一個名稱，寫法上以常數宣告，讓Facade可取用對象，若Mediator所管理的UI有子元件，每個子元件都可在此註冊，在寫法上為了避免管理的子元件尚未生成，註冊元件時應盡量寫在onRegister裡，Constructor有時會出現問題

雖然Mediator可取得Proxy跟其它的Mediator，但會耦合性會過高，以Notification通知Command，再以Command操作Proxy的方式比較妥當，而Mediator去操作其它的Mediator是絕對不允許的

Proxy同Mediator要有一個識別名，用來管理資料及封裝操作的方法，實現Domain Logic，在官方文件還有一種RemoteProxy，不過我個人比較喜歡拆成Delegate跟Proxy，讓Delegate管遠端要值的方法，方便之後抽換

RSSProxy

package idv.gd.pureMVCTest.model
{
        import idv.gd.pureMVCTest.ApplicationFacade;
        import idv.gd.pureMVCTest.model.business.RSSDelegate;
        import idv.gd.pureMVCTest.model.vo.InfoVO;
        
        import mx.collections.ArrayCollection;
        import mx.controls.Alert;
        import mx.rpc.IResponder;
        
        import org.puremvc.as3.patterns.proxy.Proxy;
        
        /**
         * proxy用來維護資料，保有原始資料及操作方法
         */
        public class RSSProxy extends Proxy implements IResponder
        {
                public static const NAME:String = "DataProxy";
                
                public function RSSProxy(data:Object = null)
                {
                        super(NAME, data);
                }
                
                /**
                 * 使用 delegate來取得內容，使用 delegate才方便抽換取得來源
                 */
                public function getRealNews():void
                {
                        var delegate:RSSDelegate = new RSSDelegate(this);
                        
                        delegate.getNews();
                }
                
                public function getTech3c():void
                {
                        var delegate:RSSDelegate = new RSSDelegate(this);
                        
                        delegate.getTech3c();
                }
                
                public function removeItemAt(index:uint):void
                {
                        if (infoVO)
                        {
                                infoVO.content.removeItemAt(index);
                        }
                }
                
                public function removeAll():void
                {
                        infoVO.content.removeAll();
                }
                
                public function result(resultEvent:Object):void
                {                       
                        var data:Object = resultEvent.result;
                        var title:String = data.rss.channel.title;
                        var lastBuildDate:String = data.rss.channel.lastBuildDate;                      
                        var content:ArrayCollection = data.rss.channel.item;
                        
                        var vo:InfoVO = new InfoVO(title, lastBuildDate, content);
                        
                        this.data = vo;
                        
                        this.facade.sendNotification(ApplicationFacade.RSS_LOAD_COMPLETE, infoVO);
                }
                
                public function fault(data:Object):void
                {
                        this.facade.sendNotification(ApplicationFacade.RSS_LOAD_FAULT);
                }
                
                protected function get infoVO():InfoVO
                {
                        return data as InfoVO;
                }

      }
}

在多核心的版本，其實只是多了一組管理Facade的Map，跟Mediator及Proxy一樣，生成時要有個識別的名字，其它用法一樣

Main.mxml

//進入點要有識別名，用來識別 facade instance
public const NAME:String = "Main";
private var facade:ApplicationFacade = ApplicationFacade.getInstance(NAME);

ApplicationFacade

public function ApplicationFacade (key:String)
{
        super(key);
} 

原始檔下載（Flex專案檔，附PureMVC Standard）