You can create a derived instance from a reference instance
and use this derived instance to generate the reference instance with
different generation parameters, without duplicating its design.
Derivation is available for the following entities: Program,
Screen, Server, Data Structure (for the generation of the Copybooks
and the error messages), Dialog (for the generation of the error messages),
and Server Dialog.
It is useful when an instance must be generated
with different generation parameters. You use it, for example, to
generate a Program for CICS and for IMS. So, you create a derived
instance that points to a reference instance and to a generation Library.
This derived instance does not contain any design. You can then generate
the reference instance from another Library without duplicating its
design.
To create the derived instance, you must use the creation
wizard of the entity. For example, you use the Program creation wizard
to create an instance that is derived from a Program instance. Enter
its required fields and check the
Create a derived entity box.
Then, specify the instance that it is derived from in the
<Entity>
to derive field.
Tip: You can leave the Name empty,
check the Create a derived entity box, and
enter the reference instance. The name of the derived instance is
then automatically initialized with the name of the reference instance.
You need to complement this name with the Library or any other distinctive
code. This way, they can be easily associated among all the available
instances.
The derived instance is
displayed in the Design Explorer view, under
the entity it is derived from. Double-click the instance to open its
editor.
Then, you must generate the derived instance. It generates
the reference instance but with the generation parameters of the Library
that is selected in the derived instance.
Note: If the design of the
reference instance has been modified, the generation of the derived
instance takes this modification into account, except if the change
was only a change of Library.