I tried now a different approach debugging the app to see what is happens and i see this:

- It changes the view and register the mediator just like the ApplicationMediator i posted.
- Now i add a creationComplete in Main.mxml on the view "userManagerPanel"
- And when it's debbug first change view and register mediator, but it does't create complete the View so because of this i got the null reference

So what is the best way to register the mediator? it's a best practice put a creationComplete in the view to send a notification to register the mediator?
Because the problem i am getting is that it register the Mediador but the View isn't totally build so when i register the mediator the view are loading and don't instanciate the userList.

I have to thank you cliff by all the support and assistance you have given, thank you.

Daniel Gomes

Hi Cliff,

no i am doing it just the way you post in the newer FAQ entry, i will post to you the ApplicationMediator.

:

package com.pt.onedesign.user_manager.view
{

import com.pt.onedesign.user_manager.model.LoginProxy;
import com.pt.onedesign.user_manager.model.UserProxy;

import mx.controls.Alert;
import mx.core.Container;

import org.puremvc.as3.interfaces.IMediator;
import org.puremvc.as3.interfaces.INotification;
import org.puremvc.as3.patterns.mediator.Mediator;

public class ApplicationMediator extends Mediator implements IMediator
{
//Define Proxy
private var _loginProxy : LoginProxy;
private var _userProxy : UserProxy;

//Define static const for mediator
public static const NAME:String = "ApplicationMediator";

// Define const names for change ViewStack views.
public static const LOGIN_PANEL : int = 0;
public static const USER_MANAGER_PANEL : int = 1;

public function ApplicationMediator( viewComponent: Main ):void
{
super ( NAME, viewComponent );

// local reference to the LoginProxy
_loginProxy = facade.retrieveProxy(LoginProxy.NAME) as LoginProxy;

facade.registerMediator(new LoginPanelMediator(app.loginPanel));
//facade.registerMediator(new  UserListMediator(app.userManagerPanel.userList));
}



override public function listNotificationInterests():Array
{
    return [ LoginProxy.LOGIN_SUCCESS,
    LoginProxy.LOGIN_FAILED
            ]
}

override public function handleNotification( note:INotification ):void
{
switch ( note.getName() )
{
   case LoginProxy.LOGIN_FAILED:
Alert.show("Invalid username or password, please try it again.","Login Failed");
app.currentViewSelector = LOGIN_PANEL;
break;

   case LoginProxy.LOGIN_SUCCESS:
    app.currentViewSelector = USER_MANAGER_PANEL;
    facade.registerMediator(new UserListMediator(app.activeView.userList));
    facade.sendNotification(UserProxy.GET_USERS_LIST);
        break;
}
}

protected function get app(): Main
{
   return viewComponent as Main;
}
}
}
i have and id for userManagerPanel,userList and userForm but i didn't give them a "name" property. I am getting the view this form:

Main.mxml

:

[Bindable] public var currentViewSelector:int = ApplicationMediator.LOGIN_PANEL;
            public var activeView:Object;


]]>
</mx:Script>

  <mx:Binding source="appView.selectedChild" destination="activeView" />
<mx:ViewStack id="appView" resizeToContent="true" selectedIndex="{currentViewSelector}" >
<loginComp:LoginPanel id="loginPanel"/>
<userManagerComp:UserManager id="userManagerPanel"/>
</mx:ViewStack>
The unique difference between my code and yours of the FAQ post is that i dont have a button and i change the view and add the mediator when a LOGIN_SUCCESS notification is send, and my public var currentViewSelector:int and yours is String (but if i change to string give me an error).

Daniel Gomes

Hi Guys,

I have been testing the Demo Pipes and I am with many difficulties to understand, then I would like to ask if someone could develop a simpler or more easy to understand demo? (something "basic")

Thanks,

Daniel Gomes

Well, i tried, tried, tried and nothing only still give me null reference  so my question is i need to have a mediator to UserManagerPanel to instance is components?

I am really stuck on it and i dont understand why it dont instantied it and give me null reference i implemented you solution but the child of UserManager like UserList and UserForm still give me null  i debug from a lot of different ways and still see the null 

And the stupid thing is, it puts the components in the view but dont give them an instance 

Daniel Gomes

Humm, i think i know what is happen, because when the notification is send of LOGIN_SUCCESS the UserList Mediator will try to fill datagrid with data and at this time the Mediador isn't created and the instance so i think i have to send another notification like: GET_USERS_LIST after switch the views and add the UserListMediator, i will try and send a feedback of it.

Daniel Gomes

Hi rhart,

I can't help you much (i am a newbie) but i can tell you that error "can't reference null object" you are getting maybe is because you are trying to communicate with an object/component that is not instance in the application and you dont have any reference to him, i am getting this error too 

Daniel Gomes

I was trying implement it but getting null again :s

will post the code:

Main.mxml

:

<?xml version="1.0" encoding="utf-8"?>
<mx:Application
xmlns:mx="http://www.adobe.com/2006/mxml"
layout="horizontal"
xmlns:loginComp="com.pt.onedesign.user_manager.view.components.Login.*"
xmlns:userManagerComp="com.pt.onedesign.user_manager.view.components.UserManager.*"
initialize="facade.startupApp(this)">

<mx:Script>
<![CDATA[
import com.pt.onedesign.user_manager.view.ApplicationMediator;
import com.pt.onedesign.user_manager.ApplicationFacade;

private var facade:ApplicationFacade = ApplicationFacade.getInstance();

            [Bindable] public var currentViewSelector:uint = ApplicationMediator.LOGIN_PANEL;
            public var activeView:Object;


]]>
</mx:Script>

  <mx:Binding source="appView.selectedChild" destination="activeView"/>
<mx:ViewStack id="appView" resizeToContent="true" selectedIndex="{currentViewSelector}">
<loginComp:LoginPanel id="loginPanel" />
<userManagerComp:UserManager id="userManagerPanel"/>
</mx:ViewStack>
</mx:Application>
ApplicationMediator.as

:

package com.pt.onedesign.user_manager.view
{

import com.pt.onedesign.user_manager.model.LoginProxy;
import com.pt.onedesign.user_manager.model.UserProxy;

import mx.controls.Alert;
import mx.core.Container;

import org.puremvc.as3.interfaces.IMediator;
import org.puremvc.as3.interfaces.INotification;
import org.puremvc.as3.patterns.mediator.Mediator;

public class ApplicationMediator extends Mediator implements IMediator
{
//Define Proxy
private var _loginProxy : LoginProxy;
private var _userProxy : UserProxy;

//Define static const for mediator
public static const NAME:String = "ApplicationMediator";

// Define const names for change ViewStack views.
public static const LOGIN_PANEL : Number = 0;
public static const USER_MANAGER_PANEL : Number = 1;

public function ApplicationMediator( viewComponent: Main ):void
{
super ( NAME, viewComponent );

// local reference to the LoginProxy
_loginProxy = facade.retrieveProxy(LoginProxy.NAME) as LoginProxy;

facade.registerMediator(new LoginPanelMediator(app.loginPanel));
//facade.registerMediator(new  UserListMediator(app.userManagerPanel.userList));
}

protected function get app(): Main
{
   return viewComponent as Main;
}

override public function listNotificationInterests():Array
{
    return [ LoginProxy.LOGIN_SUCCESS,
    LoginProxy.LOGIN_FAILED
            ]
}

override public function handleNotification( note:INotification ):void
{
var child:Container;
switch ( note.getName() )
{
   case LoginProxy.LOGIN_FAILED:
Alert.show("Invalid username or password, please try it again.","Login Failed");
app.currentViewSelector = LOGIN_PANEL;
break;

   case LoginProxy.LOGIN_SUCCESS:
    app.currentViewSelector = USER_MANAGER_PANEL;
    facade.registerMediator(new UserListMediator(app.activeView.userList));
        break;
}
}


}
}
UserManager.mxml (Component that receive more 2 components)

:

<?xml version="1.0" encoding="utf-8"?>
<mx:Canvas
width="900"
xmlns:comps="com.pt.onedesign.user_manager.view.components.UserManager.components.*"
xmlns:mx="http://www.adobe.com/2006/mxml">

<mx:HBox horizontalGap="10" horizontalAlign="center" verticalAlign="top" width="100%" paddingTop="15">
<mx:VBox verticalGap="10">
<comps:UserList id="userList"/>
</mx:VBox>
<comps:UserForm id="userForm"/>
</mx:HBox>

</mx:Canvas>

It's strange, but the same thing in ApplicationMediator.as if i put the this:

:

case LoginProxy.LOGIN_SUCCESS:
app.currentViewSelector = USER_MANAGER_PANEL;
        app.activeView.creationPolicy=all; <------------ It make the other components avaible but without this they still null :|
facade.registerMediator(new UserListMediator(app.activeView.userList));
break;
I really don't understand why it don't load the components :|

This new FAQ entry will help the some people with the same question and the way that you cover and explain in, is very easy to understand.

Now i will implement this and will try to finish my first app ("User Manager Demo App").
When i finish it, i will put online maybe can help other guys that are starting with PureMVC using WebOrb|php and Mysql

Daniel Gomes

It works perfect now

Thanks Cliff!

Daniel Gomes

Hi guys,

I am having some difficulties loading views components in viewstack.
See the steps:

- MainApp load
- ViewStack default view: A
- I loggin
- ViewStack Changes view to: B
- View B have more two components inside (B.1,B.2)
- When i tried send data for components B.1 and B.2 their are unavaible it sends an error that object is null

So i have doing some search and find maybe it's creationPolicy, the default is auto and i changed for all and the objects are now avaliable.

But my question/difficulty is load the components without the creationPolicy all, becaus now my App just have 2 views and 3 components, but when i have 50 components load all at same time dont make sense and make the server slow and the application, or am i wrong? What is the best practice to do this?

Thanks,

Daniel Gomes

Hi Cliff, thanks for reply.

I was trying modularity first, until i faced this problem i will see the pipeworks demo and is code and try to understand it. For now exists any topic or article explaning the difference between pipes and modularity?

Thanks,

Daniel Gomes

Hi guys,

I am starting now with AS3 Multicore, and i'm facing a problem.
I have a flex library that for now contain a Login Module that is attach to my project. When i loggedin in LoginPanel it sends a notification and my question is what is the best away/practice to make it reusable and without Login Module have to know the main project?

I thought maybe Login Module sending a notification that main project can hear and handle but i don't know if it's possible and if it is who to do it.

Thanks,

Daniel Gomes

Have good news, for now it removes the Login Panel and add the Main App Painel (i changed some names and organized better the components).

But i still have some problems, because i only can remove the Login Panel with "app.removeChildAt(0)" if i tried with "app.removeChild(loginPanel)" it give a error :S and to add the Main App Painel i have to create a var and create a new MainApp. (see below in code)

This is my ApplicationMediator.as

:

//Define Proxy
private var _loginProxy : LoginProxy;
private var _userProxy : UserProxy;

//Define static const for mediator
public static const NAME:String = "ApplicationMediator";

public function ApplicationMediator( viewComponent: Login ):void
{
super ( NAME, viewComponent );

// local reference to the LoginProxy
_loginProxy = facade.retrieveProxy(LoginProxy.NAME) as LoginProxy;
_userProxy = facade.retrieveProxy(UserProxy.NAME) as UserProxy;

facade.registerMediator(new LoginPanelMediator(app.loginPanel));
}

override public function listNotificationInterests():Array
{
    return [   ApplicationFacade.LOGIN_SUCCESS,
    ApplicationFacade.LOGIN_FAILED,
            ]
}

override public function handleNotification( note:INotification ):void
{
switch ( note.getName() )
{
   case ApplicationFacade.LOGIN_FAILED:

break;

   case ApplicationFacade.LOGIN_SUCCESS:
    app.appView.removeChildAt(0);
    var mainAppPanel: MainApp = new MainApp();
    app.addChild(mainAppPanel);
        break;
}
}

private function get app(): Login
{
   return viewComponent as Login;
}

// assuming the login panel is there first and has id loginPanel.
private function get loginPanel(): Login
{
   return app.loginPanel as Login;
}
My MainAppCommand.as

:

/**
* Listens to the login notification retrieving the LoginProxy and does login
*/
override public function execute(note:INotification):void
{
    var userVO:UserVO = note.getBody() as UserVO;
    var mainApp:MainApp = new MainApp();
    mainApp.id = 'mainAppPanel';
    sendNotification( ApplicationFacade.LOGIN_SUCCESS );
    sendNotification( ApplicationFacade.ADD_MAIN_APP );
}

My ApplicationFacade.as

:

//Notifications const names
public static const STARTUP_APP:String = "startupApp";

//Login const names
public static const LOGIN:String = "login";
public static const LOGIN_SUCCESS:String  = "loginSuccess";
public static const LOGIN_FAILED:String  = "loginFailed";

//Main const names
public static const MAIN_APP:String  = "mainApp";
public static const ADD_MAIN_APP:String  = "addMainApp";


/**
* Singleton ApplicationFacade Factory Method
*/
public static function getInstance() : ApplicationFacade
{
if( instance == null) instance = new ApplicationFacade();
return instance as ApplicationFacade;
}

/**
* Start the application
*/
public function startupApp(app:Login):void
{
sendNotification(STARTUP_APP, app);
}

/**
* Register Commands with the Controller
*/
override protected function initializeController( ) : void
{
super.initializeController();
registerCommand( STARTUP_APP, StartupAppCommand );
registerCommand( LOGIN, LoginCommand );
}

And this is my new File Structure:


Something is missing me, just dont know where :S

UPDATE: I just upload the App you can see it here:
http://onedesign.com.pt/puremvc/Login.html
Username: admin Password: admin

Thanks for your time,

Daniel Gomes

Now it starts to make sense to me

Thanks for the explanation again Cliff, it was very usefull. Now i will try implement it!

Daniel Gomes

Hi Cliff,

Yes you are assuming right, i have a ViewStack with LoginPanel and UserManagementContainer as a child and the objectivo is switch between them.

Now i understand a little more the "concept" of ApplicationMediator, but i have another question maybe a stupid one, so and if i dont have a ViewStack in main app, how the ApplicationMediator remove/add views from main app?


Thanks for your reply and explanation,

Daniel Gomes