Validation of user inputs when using ItemRenderers in DataGrid

Question

Hi,
I have to show multiple editable columns in a DataGrid.
The columns may have different formats and datatypes e.g.
numbers, dates, string etc.
So I am using TextInput/DateField as a ItemRenderer inside
the DataGrid. I have also set the rendererIsEditor="true".
Now I want to apply validation to all these editable columns
depending on their datatypes.
I know I can do that by applying validators individually on
each column.
But is there a way I can use common validation for all the
columns that have a similar datatype or that have the same
renderer?

Answer 1

You can use the itemEditEnd Event of the DataGrid for your
validation. Then you can use Actionscript to make sure what the
user enters is in the right format. Example:
<mx:Script>
<![CDATA[
import mx.events.DataGridEvent;
public function processEdit(event:DataGridEvent):void {
cellValue =
TextInput(event.currentTarget.itemEditorInstance).text; // the
entered text
cell = event.dataField; //the datafield attribute of the
column
// Determine if the new value is too long for nvarchar field
if(cell == 'WLNET' && cellValue.length > 35) {
cellValue = cellValue.substr(0,35); //shortening it for user
demonstrates expected length
TextInput(event.currentTarget.itemEditorInstance).text =
cellValue;
event.preventDefault(); // Prevent the user from removing
focus, and leave the cell editor open.
// Write a message to the errorString property.
// This message appears when the user mouses over the
editor.
TextInput(event.currentTarget.itemEditorInstance).errorString="Entered
text too long.";
return;
]]>
</mx:Script>
<mx:DataGrid id="enrolled_dg" editable="true"
itemEditEnd="processEdit(event);">
I learned part of this from the Flex documentation online:
Determining
the reason for an itemEditEnd event