<!--This editor will make sure that the text entered is between 2 and 4 characters long-->
<igEditors:XamTextEditor x:Name="textEditor3" InvalidValueBehavior="DisplayErrorMessage" >
    <igEditors:XamTextEditor.ValueConstraint>
        <igEditors:ValueConstraint MinLength="2" MaxLength="4" />
    </igEditors:XamTextEditor.ValueConstraint>
</igEditors:XamTextEditor>