Separating MXML and Actionscript - apache-flex

From this tutorial http://www.brighthub.com/internet/web-development/articles/11010.aspx
I found the code below. Is there a way to break this out so the mxml file just has the mxml, and the code between the script tags is put in an actionscript file?
Thanks.
-Nick
<mx:Application
xmlns:mx="http://www.adobe.com/2006/mxml"
layout="absolute"
width="600"
height="400"
frameRate="100"
creationComplete="CreationComplete()"
enterFrame="EnterFrame(event)">
<mx:Script><![CDATA[
public function CreationComplete():void
{
}
public function EnterFrame(event:Event):void
{
}
]]></mx:Script>
</mx:Application>

There are several ways of achieving this in Flex:
Put the AS code in a .as file and use the "source=yourfile.as" attribute in the Script tag:
<mx:Script source="yourfile.as" />
You can also use the includes="yourfile.as" declaration w/in the Script tag:
<mx:Script
<![CDATA[
include "yourfile.as";
//Other functions
]]>
</mx:Script>
Use a Code-Behind pattern where you define the code in an AS file which extends the visual component you want your MXML file to extend. Then your MXML file simple extends the AS file and you have (via inheritance) access to all the code. It would look something like this (I'm not sure if this would work for the main MXML file which extends Application):
AS File:
package {
public class MainAppClass {
//Your imports here
public function CreationComplete():void {
}
public function EnterFrame(event:Event):void {
}
}
}
MXML File:
<component:MainAppClass xmlns:component="your namespace here"
xmlns:mx="http://www.adobe.com/2006/mxml"
layout="absolute"
width="600"
height="400"
frameRate="100"
creationComplete="CreationComplete()"
enterFrame="EnterFrame(event)">
</component:MainAppClass>
Use a framework to inject the functionality you are looking for as a type of "model" which contains the data-functionality you will use. It would look something like this in Parsley:
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
layout="absolute"
width="600"
height="400"
frameRate="100"
creationComplete="model.CreationComplete()"
enterFrame="model.EnterFrame(event)">
<mx:Script>
<![CDATA[
[Inject]
[Bindable]
public var model:YourModelClass;
]]>
</mx:Script>
</mx:Application>
Two frameworks which come to mind which can help w/injection are Mate or Parsley.
I'm not sure if the code-behind pattern works with the main MXML file (which extends Application), so if you're having problems, you might try breaking out the content in your Main MXML file into a separate component which is included in Main. It might look something like this:
Main.mxml:
<mx:Application blah,blah,blah>
<component:YourComponent />
</mx:Application>
YourComponent.mxml:
<component:YourComponentCodeBehind creationComplete="model.creationComplete()"...>
//Whatever MXML content you would have put in the Main file, put in here
</component:YourComponentCodeBehind>
YourComponentCodeBehind.as
package {
class YourComponentCodeBehind {
//Whatever AS content you would have put in the Main .as file, put in here
}
}
From what I've been able to gather from Flex architecture, this is a very common way of setting up your application: your main MXML includes a single "view" which is the entry-point to the rest of your application. This view the contains all other views which comprise the app.
Hope that makes sense :)

Related

Flash builder 4.6 - code behind approach

I'm trying to figure out the right approach for "Code behind" using flash builder for a mobile app:
I'm creating a flex mobile AIR project (Based on the "Tabbed view" template)
setting my UI in design mode
now I want all the logic to be in a separate class that will change the UI look accordingly
Sounds easy, however I can't really get the approach for doing it, any help is appreciated :)
Update:
main app:
<?xml version="1.0" encoding="utf-8"?>
<s:TabbedViewNavigatorApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark" applicationDPI="160">
<s:ViewNavigator label="a" width="100%" height="100%" firstView="views.aView"/>
<s:ViewNavigator label="b" width="100%" height="100%" firstView="views.bView"/>
<fx:Declarations>
<!-- Place non-visual elements (e.g., services, value objects) here -->
</fx:Declarations>
</s:TabbedViewNavigatorApplication>
view A:
<?xml version="1.0" encoding="utf-8"?>
<s:View xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark" title="a">
<fx:Declarations>
<!-- Place non-visual elements (e.g., services, value objects) here -->
</fx:Declarations>
<s:Label id="txt" x="280" y="139" text="Label"/>
</s:View>
So now I want MyClass to change txt textField according to my logic, what is the right approach?
An elegant way would be implementing IMXMLObject. When implementing this interface, the IMXMLObject#initialize method will take the component (named document of type Object) and an optional id (of type String) as arguments and u can easily implement this pattern. The big advantage is, that you use composition over inheritance and when using interfaces, you can use it as some sort of type save mix-in as view behavior:
package net.icodeapp.examples.views
{
import flash.events.MouseEvent;
import mx.core.IMXMLObject;
import mx.events.FlexEvent;
public class ViewBaseModel implements IMXMLObject
{
//-------------------------------------------------------------------------
//
// Properties
//
//-------------------------------------------------------------------------
private var _id:String;
private var _viewBase:ViewBase;
protected function set viewBase(value:ViewBase):void
{
_viewBase = value;
if (!_viewBase)
throw new ArgumentError('View must be instance of ViewBase');
if (!_viewBase.initialized)
_viewBase.addEventListener(FlexEvent.CREATION_COMPLETE, viewBase_creationCompleteHandler, false, 0, true);
else
viewCreationCompleted();
}
//-------------------------------------------------------------------------
//
// Constructor
//
//-------------------------------------------------------------------------
public function ViewBaseModel()
{
}
//-------------------------------------------------------------------------
//
// Methods
//
//-------------------------------------------------------------------------
public function initialized(document:Object, id:String):void
{
viewBase = document as ViewBase;
_id = id;
}
private function viewCreationCompleted():void
{
_viewBase.addEventListener(MouseEvent.CLICK, viewBase_clickHandler);
}
//-------------------------------------------------------------------------
//
// Event Handler
//
//-------------------------------------------------------------------------
private function viewBase_creationCompleteHandler(event:FlexEvent):void
{
viewCreationCompleted();
}
private function viewBase_clickHandler(event:MouseEvent):void
{
// todo: do some action
}
}
}
The model is initialized and references are set by the framework. When taking a peek at the generated ActionScript code you'll see, that IMXMLObject#initialize it called in the constructor after the model is instantiated.
<?xml version="1.0"?>
<s:Group xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:views="net.icodeapp.examples.views.*">
<fx:Declarations>
<views:ViewBaseModel/>
</fx:Declarations>
</s:Group>
The model would receive by events by the view and can call methods on it.
All you do is make an AS file that has the same base class as whatever your MXML object was initially set up as, for example if it's a VGroup make MyBaseClass extends VGroup, then change the VGroup to MyBaseClass.
Example
[Main.mxml]
<main:MainBase
xmlns:main="*"
...>
</main:MainBase>
[MainBase.as]
public class MainBase extends Application
Think of your Code Behind as a base class (or an Abstract Class). In an Abstract Class, it is really common for the actual implementation of methods or the "real objects" behind properties to be left to the extending class(es) to supply.
This is exactly like what you do when you set a base class in Flash to your custom Class, but the actual member objects (buttons, etc.) are provided on the stage of the MovieClip whose library instance is linked to your clip.
For more on code behind, check out my blog post here. If you'd like to check out the code for the template component described there, look here. Though template components are less useful in the Spark world (IMO).

fx:script for AS3 and MXML for?

I find the flexibility in using fx:script to get all AS3 see each other easily but I have a few MXML module, some actionscript from main.mxml want to access the ID in specific module such as module1.mxml. How do I get it to work?
Assuming you have a module1.mxml is a defined component in main.mxml, you can give it an ID and reference public variables and functions inside of it. The following shorthand code demonstrates this.
<mx:Application creationComplete="creationCompleteHandler()">
<fx:Script>
function creationCompleteHandler() : void
{
m1.initializeModule();
}
</fx:Script>
<module1 id="m1" />
</mx:Application>

Flex' VideoDisplay control does not open stream

I'm trying to make VideoDisplay playing media with FlashDevelop. Here's the source of my application:
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">
<mx:Script>
<![CDATA[
import mx.events.VideoEvent;
private function pause():void
{
if (moo_player.state == VideoEvent.PLAYING)
moo_player.pause(); else
if (moo_player.state == VideoEvent.PAUSED)
moo_player.play();
}
]]>
</mx:Script>
<mx:Panel>
<mx:VideoDisplay
source="bar.flv"
width="640"
height="480"
maintainAspectRatio="true"
id="moo_player"
autoPlay="true"
doubleClick="pause();"
doubleClickEnabled="true"
/>
</mx:Panel>
</mx:Application>
The problem is when i build application and run it (unfortunately, got no idea how to run it without KMPlayer or Mozilla - Flash Player is a plugin afaik) i got no video. The movie file is in the same directory as application's "Application.flv" one. But if i reload application (within player or browser) a few times, video starts.
So, here are my questions:
what's wrong with VideoDisplay
component and how to fix this
'non-playing'?
what's the better way
to execute application than running
it within movie player or browser?
P.S.: please, do not get mad of my knowledge lacks - i began to use Flex nearly 30 minutes ago.
You should be using Spark components, not MX components. Try this:
<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx">
<s:VideoPlayer source="bar.flv" width="640" height="480" />
</s:Application>
There's some issues with video display internally in the component. One of the only flex components that's kind of poorly done in some ways. Please don't let it discourage you from exploring Flex.
Create a custom component that extends it, create a file named CustomVideoDisplay.as with this code:
package
{
import mx.controls.VideoDisplay;
public class CustomVideoDisplay extends VideoDisplay
{
[Bindable]
override public function get source():String
{
return super.source;
}
override public function set source(value:String):void
{
super.source = value;
play();
}
public function CustomVideoDisplay()
{
super();
}
}
}
Then add this into your root <application> tag :
xmlns:local="*"
And for your video component, refer to it as:
<local:CustomVideoDisplay
source="bar.flv"
width="640"
height="480"
maintainAspectRatio="true"
id="moo_player"
autoPlay="true"
doubleClick="pause();"
doubleClickEnabled="true"
/>
Let me know if this doesn't do the trick for you!
Well, i thought: my player will be ran at client-side of web project, and in FireFox that code runs successfully each of seven runs. I think this would be enough for testing and implementation.
Thanks everyone for the trouble-taking!

calling function from actionscript (.as) file for button in mxml

Can anyone help me in this regard?
I have Actinscript file in which I have defined a function like below:
actionScript.as (file name)
import mx.controls.Alert;
public function abc():void{
Alert.show("Inside abc(): My Button Clicked");
}
Now I have a button in mxml and I am calling the above function in my buttion "click" attribute like below.
Importing script in mxml:
<mx:Script source="actionScript.as" />
Using function:
<mx:Button id="button1" label="My Button" click="abc()"/>
Can any one help me? Is there anything else I need to do or am I going wrong somewhere?
create a new project and make these 2 files
test.mxml
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
<mx:Script source="includes/test.as"/>
<mx:Button label="Alert Test" click="abc()" />
</mx:Application>
src/includes/test.as
// ActionScript file
import mx.controls.Alert;
public function abc():void{
Alert.show("Inside abc(): My Button Clicked");
}
works fine for me
wrap up your .as file in a package and class reference. instantiate the class in your MXML and call the function using instantiated class.
var Class1:Something = new Something();
Class1.abc();

Access to elements defined in MXML from External AS

I have a MXML with a form, and inside it, two TextInputs. I hate having any piece of code inside the MXML file (I come from a JavaScript formation) so I use a
mx:Script source="external.as"
tag to include any code used in any MXML file. The problem is that if I have this code on the external.as file:
private function populateFromForm():void{
var vo:ValidObject= new ValidObject();
vo.market = marketInput.text;
vo.segment = segmentInput.text;
vo.priceLow = priceLowInput.text;
vo.priceHigh = priceHighInput.text;
}
Where marketInput, segmentInput, priceLowInput and priceHighInput are TextInputs defined in the MXML file. When I try to complile I get a 1120: Access to undefined property XXXXX
I have tried adding this lines prior to the function:
public var marketInput:TextInput;
public var segmentInput:TextInput;
public var priceLowInput:TextInput;
public var priceHighInput:TextInput;
But instead I get a 1151:A conflict exists with definition XXXX in namespace internal which makes perfect sense.
Is there a way to do this without having to pass all the input references to the function as parameters of it?
You need to create a reference to an instance of the TextInputs' parent container, and then use that reference to accsess the TextInputs and their properties. I think we need some clarification on your file structure. How are you creating the instance of the parent container? I'm thinking this is what you need to do:
MyForm.mxml:
<?xml version="1.0" encoding="utf-8"?>
<mx:VBox xmlns:mx="http://www.adobe.com/2006/mxml">
<mx:TextInput id="marketInput" />
<mx:TextInput id="segmentInput" />
<mx:TextInput id="priceLowInput" />
<mx:TextInput id="priceHighInput" />
</mx:VBox>
SaveVOContainer.as:
package
{
public class SaveVoContainer extends Container
{
private var myForm:MyForm = new MyForm();
public function SaveVOContainer
{
this.addChild(myForm);
}
private function populateFromForm():void{
var vo:ValidObject= new ValidObject();
vo.market = myForm.marketInput.text;
vo.segment = myForm.segmentInput.text;
vo.priceLow = myForm.priceLowInput.text;
vo.priceHigh = myForm.priceHighInput.text;
}
}
}
Doing a "code-behind" is painful in Flex. There is no concept of partial classes or the flexibility of prototypal inheritance as in Javascript. Google for "code-behind in flex" for many resources.
I think it's better you get used to the idea of embedding code in mxml. Use script tags avoiding inline code as much as possible. If you have to write a lot of code within MXML, perhaps you may want to re-factor the code into multiple custom components. Bonus points if they are reusable.
The canonical way to do code-behind in Flex is via inheritance. Here's a good explanation from the docs: http://learn.adobe.com/wiki/display/Flex/Code+Behind. In a nutshell:
Declare an ActionScript class to use as your base class.
Set the base class as the root container in your MXML file.
For any controls declared in your MXML file, you have to redeclare them as public members of the base class using the exact same name (exactly as you are doing above for your script block with source tag, only it works :-)
So, your ActionScript file:
package mypackage
{
import mx.controls.TextInput;
public class myClass extends WindowedApplication
{
public var marketInput:TextInput;
private function populateFromForm():void{
/* As above */
}
}
}
And the corresponding MXML file:
<?xml version="1.0" encoding="utf-8"?>
<custom:myClass xmlns:custom="mypackage.*"
xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx">
<mx:TextInput id="marketInput"/>
</custom:myClass>
Et cetera for your other TextInput controls. And now your populateFromForm function should work.
It is kind of heinous to have to redeclare the same entities twice, but it's not quite the bag of hurt the earlier respondent made it out to be (although it's possible this changed in Flex 4 to make it less painful than it was).
import this in .AS:
import mx.core.Application;
in the .AS use this:
mx.core.Application.application.component.property = value;
mx.core.Application.application.myText.text = 'test';
do you have a script tag in your mxml file that points to your ActionScript file?
<mx:Script source='includes/foo.as' />

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