In the well-structured software roundup "SQL Front Ends for Windows" (October 1994), Mark Hettler and Scott Higgs give a largely accurate view of PowerBuilder 3.0a. But they miss a couple of tricks. They say that "you cannot derive a user object from a button." In fact, PowerBuilder provides standard user objects that provide this capability. These specialized standard objects can have events, scripts, functions, and variables added. At Ernst & Young, we use standard user objects extensively to provide common user-interface functions across a range of commercial software.
The authors also imply that user objects can be shared by moving them between libraries. PowerBuilder not only allows a library of user objects and other reusable components to be part of several applications, it also allows inheritance of these objects into specia
lized objects. We use this feature extensively as well. All our commercial applications inherit from objects in a shared ancestor library.
James Taylor
Development Manager, Ernst & Young
Las Colinas, TX
Flexible C++
Matthew Wilson
My approach to software engineering is far more pragmatic than it
is
theoretical--and no language better exemplifies this than C++.
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Inheritance in PowerBuilder
