Following up on my previous post on the use of Eventing for model management today’s post will demonstrate how to use eventing effectively on the validateWrite method of tables. This can be very useful for additional model specific data validation without overshadowing the original method.

In this example I will use the validateWrite of the PurchReqLine table.

Instructions

1. Create a new class e.g. MyPurchReqLineEventHandler

2. Create a new static method in this class e.g. public static void validateWritePurchReqLine(XppPrePostArgs _args)
3. In the class retrieve the current boolean return value so that you can take it into account: boolean ret = _args.getReturnValue();
4. Get the original PurchReqLine Table record so that you can use it in your logic: PurchReqLine line = _args.getThis();
5. Add your logic to the method taking into account the current return value e.g.
if (ret)
{
ret = purchReqLine.myField != “”;
}
6. Set the return value (either at the end of your method or within the if (ret) statement: _args.setReturnValue(ret);

7. Create the event subscription
7.1 Navigate to the PurchReqLine table in the AOT
7.2 Expand the methods section.
7.3 Right click on the validateWrite method. Click “New Event Handler Subscription

7.4 Rename the Subscription to a name that reflects your model
7.5 Modify the CalledWhen property of the Subscription to “Post”
7.6 Modify the Class property of the Subscription to “MyPurchReqLineEventHandler”
7.7 Modify the Method property of the Subscription to “validateWritePurchReqLine”

7.8 Save the class.

You’re all done. Now test and enjoy.
Please let me know if you have any comments or suggestions on the above. Keep an eye out some more samples like this in the next few days and weeks.