Question

I have a DataGrid which uses an itemRenderer to display the items in a DataGridColumn. The ItemRenderer is created in actionscript and contains the following code:

public class PromptingColumnRenderer extends Label {

    public function PromptingColumnRenderer()
    {
        super();
    }

    //When the data is empty, display the correct prompt
    override public function set data(newData:Object):void
    {
        super.data = newData;
        var value:String=data.value as String;
        var type:String=data.type as String;

        if (value=="") {
            this.setStyle("color","0x444444");
            this.setStyle("fontStyle","italic");
            if (type=="TEXT")
                this.text="Enter Text";
            else if (type=="NUMBER")
                this.text="Enter a Number";
            else
                this.text="Choose a Date";
        }
        else {
            this.setStyle("color","0x000000");
            this.setStyle("fontStyle","normal");
            this.text = value;
        }
    }
}

I set this as the ItemRenderer of my DataGridColumn with the following mxml:

<mx:DataGridColumn id="valueCol" 
            itemRenderer="com.x.x.x.PromptingColumnRenderer" 
            dataField="value" sortable="false" editable="true"/>

In this DataGrid column, I require number validation on only the data with the type=”NUMBER” field set. The problem is, when I try to declare a NumberValidator within my PromptingColumnRenderer actionscript code, the view recycles the renderer, and the NumberValidator attempts to validate non-numeric rows. What is the best way to validate only the rows with the type=”NUMBER” field set?

Answer 1

Don’t validate within your itemRenderer. Instead create a custom itemEditor. That is the piece that is created when he user enters into the field to enter new value. I believe it uses a textInput by default. But, you could use a numeric stepper, or a TextInput w/ a numericValidator.

Here is an article on itemRenderers.

I believe that is the best approach, but if you prefer to stick with what you have, and validate within the itemRenderer, then just add a conditional to prevent validation if the entered value is not a number.

Conceptually something like this:

if(Number(this.text)){
 // run validator
} else {
 // do nothing
}