CODEWITHSUNDEEP
apache-flexactionscript-3data-binding
Manel
Manel

Reputation: 147

Flex/AS3: Data binding through a refenced property

I have:

class A: with a property "data:ArrayCollection". It's my data source (data provider) and has bitmaps.

class B: has an instance of A (called "Ainst") and calls the following method: C.init( Ainst.data). To pass the data provider to Object C.

class C: has a reference of the data provider "data" (because of "init" method). It shows the arrayCollection into Images as: Image.source = data.getItemAt(0).

But C never updates its images, that is, data binding doesn't work with this scheme. I've put [Bindable] meta-tag in all properties and even classes.

class A:

public class A{ [Bindable]public var data:ArrayCollection; }

class B:

public class B{ [Bindable]public var Ainst:A; public var Cinst:C; public function init(){ Cinst = new C(); Cinst.init(A.data) } }

class C: An image menu with 3 items (bitmaps)

            <s:VGroup xmlns:fx="http://ns.adobe.com/mxml/2009" 
                  xmlns:s="library://ns.adobe.com/flex/spark" 
                  xmlns:mx="library://ns.adobe.com/flex/mx" xmlns:local="*"
                  horizontalAlign="center"
                  paddingTop="10"
                  paddingBottom="10"
                  gap="10">


            <fx:Script>
                    <![CDATA[ 
    [Bindable] public var _images:ArrayCollection; 
    public function init( images:ArrayCollection ):void{

                    _images = images;
}   
        ]]>
            </fx:Script>
            <ms:Image id="PreviousButton" smoothBitmapContent="true" width="55" height="55" source="@Embed(source='/../figures/upArrow.png')"/>
                <ms:Image id="TopItem" smoothBitmapContent="true" maintainAspectRatio="true" x="12.5" source="{_images.getItemAt(0)}" />
                <ms:Image id="MiddleItem" smoothBitmapContent="true" maintainAspectRatio="true" x="12.5" source="{_images.getItemAt(1)}"/>
                <ms:Image id="BottomItem" smoothBitmapContent="true" maintainAspectRatio="true" x="12.5" source="{_images.getItemAt(3)}"/><!-- getItemAt(2).image -->
                <ms:Image id="NextButton" smoothBitmapContent="true" width="55" height="55" source="@Embed(source='/../figures/downArrow.png')"/>
            </s:VGroup>

Any thought? Thanks.

Upvotes: 0

Views: 769

Answers (2)

Constantiner
Constantiner

Reputation: 14221

Take a look at your class A:

public class A{
    [Bindable]
    public var data:ArrayCollection;
}

The property data here isn't static. So it is related to instance of A but not A itself. Now take a look at constructor of B:

public function init(){ 
    Cinst = new C(); 
    Cinst.init(A.data);
}

And its field declaration:

[Bindable]
public var Ainst:A;

As you can see in a line

Cinst.init(A.data);

you're referring data as a static property. You should use:

public function init(){ 
    Cinst = new C(); 
    Cinst.init(Ainst.data);
}

instead.

And please keep ActionScript naming and coding conventions. Place statements in a separate lines and start identifiers with lowercase letter. It allows to read your code easier.

Upvotes: 0

TobiHeidi
TobiHeidi

Reputation: 1251

Your problem is that the function getItemAt (_images.getItemAt(0)) is NOT Bindable.

Upvotes: 1

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