Flex Mobile Project Warning "warning: unable to bind to property 'myData' on class 'com.amec.controls.Text::TextListView'"

Question

So on a Flex Mobile Project I am trying to bind the results from a Select SQLLite query to a view. But it is not displaying results and I get the following

 warning: unable to bind to property 'myData' on class 'com.amec.controls.Text::TextListView'

From FLash Builder. Below is my view class. What is it I am missing or doing wrong?

<?xml version="1.0" encoding="utf-8"?>
<amec:BaseAddView xmlns:fx="http://ns.adobe.com/mxml/2009" 
              xmlns:s="library://ns.adobe.com/flex/spark" 
              xmlns:amec="com.amec.Components.*"
              creationComplete="vw_creationCompleteHandler(event)" title="TextListView">
<amec:layout>
    <s:VerticalLayout horizontalAlign="center" paddingLeft="5" paddingRight="5" paddingTop="5" paddingBottom="5"/>
</amec:layout>
<fx:Script>
    <![CDATA[
        import com.amec.BaseSql;
        import com.amec.MenuMessage;

        import mx.events.FlexEvent;


        [Bindable]private var resultArr:ArrayCollection = new ArrayCollection();

        import mx.collections.ArrayCollection;


        protected function vw_creationCompleteHandler(event:FlexEvent):void
        {

        }

        private function get myData():ArrayCollection
        {

            var conn:BaseSql = new BaseSql();
            conn.stmt.text = "SELECT DMV_VALUE_1 FROM DOMAIN_VALUE WHERE DMV_DMN_ID = :id";
            x.parameters[":id"] = id;
            x.sqlConnection = conn.stmt.sqlConnection;
            var x:SQLStatement = new SQLStatement;

            x.text = conn.stmt.text;

            x.execute();
            var result:Array = conn.stmt.getResult().data;
            var r:ArrayCollection = new ArrayCollection();


            if (result)
            {      
                r.source = result;        
                return r;
            } else {
                return null;
            }


        }

    ]]>
</fx:Script>
<s:List id="list" top="0" bottom="0" left="0" right="0" 
        dataProvider="{myData}" labelField="DMV_VALUE_1">
</s:List>

<fx:Declarations>
    <!-- Place non-visual elements (e.g., services, value objects) here -->
</fx:Declarations>

Also I am not getting any results to show up in the view.

Answer 1

First, set the property to be Bindable:

[Bindable(event="myDataChanged")]
private function get myData():ArrayCollection{
 ...
}

Since you do not have a 'set' method defined. As such, whenever the 'myData' changes you will have to manually dispatch the myDataChanged event in order for Bindable to have an affect.

I suspect that you will also have to make myData() a public property; otherwise how will the classes that make binding work be able to introspect into your custom component in order to access the property.

Overall, it looks like you are choosing a very bad implementation approach. Is it is unusual to use a get method to make a database call and process the results. It much more common to encapsulate such code out of your view; and pass the result data into the view. There are many different ways to do this. You could do it with a singleton approach, or a dependency injection framework, or dispatching events from a service class with the result data.