The number sequence framework is used on most Details Master (Main tables) and Details Transaction (Worksheet tables) forms, for example, the sales order number is generated through a number sequence. These used to be hooked up to the form directly, or in the form handler class. This made sense previously as user interface events (new record, delete record, abandon a new record, and so on) would need to be handled. The problem with this is that if we have two forms that handle the same table, we may need to write the code twice.

The new pattern is that it is handled on the table or table handler, but called from the form or form handler class.

We will first need to create a class that defines our number sequences, and then write the code to handle them.