The ValidateProductID action sets the ProductID property to the full product identifier.
There are no ActionData messages.
The installer checks whether a product has validated successfully by checking the ProductID property. The installer sets the ProductID property to the full product identifier after a successful validation. The ValidateProductID action does nothing if the ProductID property has already been set by a successful validation or by another method.
The ValidateProductID action always returns a success, whether or not the product identifier is valid, so that the product identifier can be entered on the command line the first time the product is run.
The product identifier can be validated without having the user reenter this information by setting the PIDKEY property on the command line or by using a transform. The display of the dialog box requesting the user to enter the product identifier can then be made conditional upon the presence of the ProductID property, which is set when the PIDKEY property is validated.