使用InjectProxy、InjectMediator简化Fabrication开发

结合前两篇文章：

小试Flex框架Fabrication

Flex多国语言示例

加上Fabrication自身支持的元标签，可简化一些代码，但简化后也付出了一定的代码，那就是变量需要声明为public，而之前虽然繁琐，但却可以将其声明为private。

以InjectProxy标签为例，进行说明，先看之前的实现：

在“小试Flex框架Fabrication”的例子中，使用了AddContactFormProxy这个代理类（用于数据处理），在mediator类(继承自FlexMediator)中声明了_proxy这个变量，然后覆写onRegister方法，在该方法内对变量_proxy进行初始化，方法如下：

_proxy = retrieveProxy(AddContactFormProxy.NAME) as AddContactFormProxy;

调用retrieveProxy方法获取到AddContactFormProxy类的引用，其中AddContactFormProxy.NAME为AddContactFormProxy类中公开的静态常量

public static const NAME:String = “AddContactFormProxy”;//值为类的名称

在org.puremvc.as3.multicore.utilities.fabrication.core包下的FabricationModel类中可看到它的实现：

1: /**

       2:  * Copyright (C) 2008 Darshan Sawardekar.

       3:  *

       4:  * Licensed under the Apache License, Version 2.0 (the "License");

       5:  * you may not use this file except in compliance with the License.

       6:  * You may obtain a copy of the License at

       7:  *

       8:  * http://www.apache.org/licenses/LICENSE-2.0

       9:  *

      10:  * Unless required by applicable law or agreed to in writing, software

      11:  * distributed under the License is distributed on an "AS IS" BASIS,

      12:  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

      13:  * See the License for the specific language governing permissions and

      14:  * limitations under the License.

      15:  */

      16:  

      17: package org.puremvc.as3.multicore.utilities.fabrication.core {

      18:     import org.puremvc.as3.multicore.utilities.fabrication.utils.HashMap;    

      19:     import org.puremvc.as3.multicore.interfaces.IProxy;    

      20:     import org.puremvc.as3.multicore.utilities.fabrication.interfaces.IDisposable;    

      21:     import org.puremvc.as3.multicore.core.Model;    

      22:  

      23:     /**

      24:      * FabricationModel is the custom model implementation used internally

      25:      * by fabrication.

      26:      * 

      27:      * @author Darshan Sawardekar

      28:      */

      29:     public class FabricationModel extends Model implements IDisposable {

      30:  

      31:         /**

      32:          * Creates and returns the instance of the FabricationModel for the specified 

      33:          * multiton key.

      34:          * 

      35:          * @param multitonKey The multitonkey whose FabricationModel is to be created.

      36:          */

      37:         static public function getInstance(multitonKey:String):FabricationModel {

      38:             if (instanceMap[multitonKey] == null) {

      39:                 instanceMap[multitonKey] = new FabricationModel(multitonKey);

      40:             }

      41:             

      42:             return instanceMap[multitonKey] as FabricationModel;

      43:         }

      44:  

      45:         /**

      46:          * Stores the proxies in this model in a hash map.

      47:          */

      48:         protected var proxyHashMap:HashMap;

      49:  

      50:         /**

      51:          * Creates the FabricationModel instance.

      52:          * 

      53:          * @param multitonKey The multitonkey for this FabricationModel

      54:          */

      55:         public function FabricationModel(multitonKey:String) {

      56:             super(multitonKey);

      57:             

      58:             proxyHashMap = new HashMap();

      59:         }

      60:  

      61:         /**

      62:          * @see org.puremvc.as3.multicore.interfaces.IModel#registerProxy()

      63:          */

      64:         override public function registerProxy(proxy:IProxy):void {

      65:             proxy.initializeNotifier(multitonKey);

      66:             proxyHashMap.put(proxy.getProxyName(), proxy);

      67:             proxy.onRegister();

      68:         }

      69:  

      70:         /**

      71:          * @see org.puremvc.as3.multicore.interfaces.IProxy#retrieveProxy()

      72:          */

      73:         override public function retrieveProxy(proxyName:String):IProxy {

      74:             return proxyHashMap.find(proxyName) as IProxy;

      75:         }

      76:  

      77:         /**

      78:          * @see org.puremvc.as3.multicore.interfaces.IModel#hasProxy()

      79:          */

      80:         override public function hasProxy(proxyName:String):Boolean {

      81:             return proxyHashMap.exists(proxyName);

      82:         }

      83:  

      84:         /**

      85:          * @see org.puremvc.as3.multicore.interfaces.IModel#removeProxy()

      86:          */

      87:         override public function removeProxy(proxyName:String):IProxy {

      88:             var proxy:IProxy = proxyHashMap.remove(proxyName) as IProxy;

      89:             proxy.onRemove();

      90:             

      91:             return proxy;

      92:         }

      93:         

      94:         /**

      95:          * @see org.puremvc.as3.multicore.utilities.fabrication.interfaces.IDisposable#dispose()

      96:          */

      97:         public function dispose():void {

      98:             proxyHashMap.dispose();

      99:             proxyHashMap = null;

     100:             

     101:             removeModel(multitonKey);

     102:         }

     103:     }

     104: }

而应用时通过覆写onRegister方法，来初始化：

1: override public function onRegister():void {

       2:             super.onRegister();

       3:             

       4:             _proxy = retrieveProxy(AddContactFormProxy.NAME) as AddContactFormProxy;

       5:         }

这样之后的处理函数中就可以调用AddContactFormProxy类的方法了，如调用它的add方法：

_proxy.add();//根据方法定义传入对应的参数

而现在换成使用InjectProxy标签，将代码会会精简一些(使用了Ioc注入简化了开发中的代码编写)：

1、需要设定编译器的参数：

点击项目，右击选择属性，找到第二项“Flex编译器”，在附加的编译器参数中输入：“-locale zh_CN -keep-as3-metadata=InjectProxy,InjectMediator”

其中我使用了locale 中文语言包进行了处理，具体操作步骤可参考“Flex多国语言示例”(地址见文章最前面)

2、在需要使用的类中，使用如下的写法：

1: [InjectProxy(name="AddContactFormProxy")]

       2: public var _proxy:AddContactFormProxy;

这样就完成了对变量_proxy的初始化，后续调用可以不再使用retrieveProxy()方法了，也可以不再去覆写onREgister()方法了。

至于Mediator，则与此类似(InjectMediator)，当然也可以实现自定义标签<参数InjectMeditor的实现就好>，主要需要覆写如下方法：

1: protected function addCustomMetaDatas():Array{

       2:      return [];

       3: };

       4:         

       5: protected function addCustomProcessors():Array{

       6:      return [];

       7: };

       8:         

       9: protected function addViewPackages():Array{

      10:      return [];

      11: };

      12:         

      13: protected function addCustomFilterPackage():Array{

      14:      return [];

      15: }

具体参见包org.puremvc.as3.multicore.utilities.fabrication.global中的FabricationConfig类的代码，标签的处理逻辑可以参数包org.puremvc.as3.multicore.utilities.fabrication.injection中的ProxyInjectorProcessor类。（自己实现两个方法：processor、elementExist）

1: package org.puremvc.as3.multicore.utilities.fabrication.interfaces

       2: {

       3:     import org.puremvc.as3.multicore.interfaces.IFacade;

       4:     import org.puremvc.as3.multicore.utilities.fabrication.injection.InjectionField;

       5:  

       6:     public interface IInjectProcessor

       7:     {

       8:         function processor(field:InjectionField,  facade:IFacade ):Object;

       9:         

      10:         function elementExist(field:InjectionField,facade:IFacade = null):IFacade

      11:     }

      12: }

本文例子的完整代码下载