Calling MXML inside ActionScript class...

Question

How can i call MXML components inside my ActionScript Class.

// filename.mxml

<mx:Canvas x="181" y="180" width="333">
     <mx:Button styleName="LoginButton" id="loginButton" click="checkLogin();" x="160" y="261"/>
     <mx:TextInput styleName="loginTextInput" id="username" x="160" y="161"/>
     <mx:TextInput styleName="loginTextInput" id="password" displayAsPassword="true" x="160" y="191"/>

 </mx:Canvas>

</mx:Canvas>

// main.as [ Class File ]

var obj:filename= new filename();

     private function label_link(evt:TextEvent):void {

                obj.currentState = "defaultindex";
          obj.username.text = "";
          obj.password.text = "";
                }

Objective

I need to access the username and password fields of MXML in my ActionScript Class.

Answer 1

Say you had an MXML file in folder src/com/stackoverflow/coolstuff/MyCoolBox.MXML

import com.stackoverflow.coolstuff.MyCoolBox;
var coolBox:MyCoolBox = new MyCoolBox();
// Do something

Answer 2

Ok, series of questions:

1. Where is the other tag? Is it possible that somehow the wrong file is being used?
2. What line has the failure? Is it obj.password or could it be obj.currentState (a scoping issue)?
3. What happens when you trace( obj );
   
   1. What happens when you trace( getQualifiedClassName( obj ) )?( remember to import flash.utils.getQualifiedClassName first ).
      The second trace should be exactly the same as the import statement.
   2. When you trace( obj.numChildren ), do you get the number you expect?
   3. When you trace( obj.getChildAt( 0 ) ), do you get a Canvas?
      1. When you trace( Canvas( obj.getChildAt( 0 ) ).getChildAt( 0 ) ), do you get another Canvas?
      2. When you trace( Object( obj.getChildAt( 0 ) ).getChildAt( 0 ).getChildren() );
4. On a bit of a different line of thought -- is this an MXML Flex project or an Actionscript Flex project? (I've seen that change how MXML is handled).

These are the debugging commands I would start with. If you get unexpected results, trace everything before setting the state. Let me know if you're still stuck.

Answer 3

Have you added obj to your main.as via addChild? What is the base class of main.as? You can test this by calling obj.initialize() in your main.as constructor.

Children are not created until initialize is called, usually via addChild when the component is added to it's parent. However, your main.as is not an MXML file which means it is not automatically calling these methods.