Figure 17.30.
Setting the properties
of the lookup field.

Figure 17.31.
Testing the form with
the lookup field.

Summary

The main ideas presented in this lesson are the following:

• Power Objects is an application-development tool that is supported on the
• Windows and Mac platforms.
• Power Objects is more closely related to Visual Basic and PowerBuilder than to Oracle Forms. Its object orientation is manifested by the capability to create a new class and inherit from a class.

• Power Objects uses Oracle Basic as a scripting language for specifying the methods defined for an object.
• At the highest level, Power Objects manages three types of objects: applications, sessions, and libraries.
• An application consists of forms, reports, and classes.
• Power Objects provides a property sheet for each type of object that it supports.
• Power Objects uses two modes: Design mode and Run-Time mode. In Design mode, you assemble the objects that constitute an application. In Run-Time mode, you are able to test the behavior of a form.

What Comes Next?

On Day 18, "Developing an Application with Oracle Power Objects," you learn more about Power Objects such as the fundamentals of Oracle Basic, developing reports, creating a class object, and other topics.

Q&A

Q Is it possible to simultaneously set the properties for a group of objects?
A Yes. To do this, select all the objects whose properties you want to set either by dragging a rectangle around them or by pressing Shift and clicking each object with the mouse. When you right-click Property Sheet, you will notice that the property sheet window is titled Multiple Selection Properties. You will be able to set the properties that the objects have in common—for instance, FontSize or FontName.
Q What files are necessary to generate an executable application?
A With Power Objects, you can generate a runtime file (.PO) which can be executed with the Power Objects Run-Time executable named PWRRUN.EXE. Alternatively, you can generate a standalone executable file that doesn't require PWRRUN to execute. If you are generating a standalone executable file, you also will need the appropriate database drivers and DLLs.

Workshop

The purpose of the Workshop is to allow you to test your knowledge of the material discussed in the lesson. See if you can correctly answer the questions in the quiz and complete the exercises before you continue with tomorrow's lesson.

Quiz

1. True or false? A Power Objects application connects to an Oracle database through an application transaction object.
2. Name three types of objects that you can place on a form.
3. Give an example of a container object.

Exercises

1. Build a form for displaying and modifying information about each instructor. Display the number of classes, if any, that the instructor is scheduled to teach.
2. Modify the Student form to display the GPA of the current student.