You need to use itemEditBegin or itemEditEnd methods from the datagrid to validate your inputs
Start point from here:
i have look at the link you sent and other links as well.
In all of the example i so, none of them so how the ItemEDitor class should be build
mining if the line is itemEditor="myComponents.EditorPhoneValidator"
how does myComponents.EditorPhoneValidator is build?
Does anyone has an example?
Check this example from the link:
Example: Passing multiple values back from an item editor
This example can give you the idea in how to use a custom component.
Sorry, I don't have an example.