
Evaluating Whether to Convert or Build an Application from Scratch
2-2 Oracle Application Express Application Migration Guide
within an Oracle Database instance. Oracle Application Express requires an Oracle
database that is release 9.2.0.3 or later. To learn more, see Oracle Application Express
Installation Guide. To learn how to build applications based on existing Oracle database
tables, review Oracle Database 2 Day + Application Express Developer's Guide.
The Oracle Application Express development environment utilizes wizards within a
declarative environment and enables you to easily extend components using SQL and
PL/SQL. You can further extend the Oracle Application Express framework by
incorporating JavasScript and Asynchronous JavasScript and XML (AJAX). To learn
more, see "Implementing Business Logic" on page A-6.
Evaluating Whether to Convert or Build an Application from Scratch
Thanks to how quickly you can build a new application with in Oracle Application
Express, it may seem quicker to build an application from scratch rather than loading
the source application definitions into an Oracle Application Express conversion
project and then generating an initial design.
When compared with developing an application from scratch, converting an existing
application provides many benefits. Once the source files for the original application
are loaded into the Oracle Application Express project, all developers can review the
pertinent information without needing to refer back to Oracle Forms or Microsoft
Access. There is no need for developers to become familiar with the source tool
development environment.
Having the forms, reports, and queries loaded into a conversion project also provides
an easy way to review the functionality and application logic provided in the old
application. Even if these components are not used to generate an Oracle Application
Express application, you can view, copy, and reuse the underlying SQL.
When converting from Oracle Forms another major benefit is the ability to track the
conversion to ensure you fully implement all the business logic within the new
application. By utilizing annotations within the conversion project, you can assign
priorities, resources, and add notes or tags to any component. Completion progress
can also be tracked to provide low-level project management capabilities.
Understanding What Oracle Application Express Application Conversion
is Not
When you convert an application to Oracle Application Express, you do not simply
load the source files, press a few buttons, and magically generate a completed
application. The conversion capabilities are designed to provide an initial design that
you then must enhance and expand to fully replicate the original application. The
generated applications use the same Create Application wizard that you use to build
applications based on existing Oracle tables or views. However, instead of needing to
specify the generated pages, these are determined from the information loaded into
the conversion project. For more information on how various source components are
generated, see "Oracle Forms Generation Capabilities and Workarounds" on page A-1.
Once you have generated the initial design, you can take full advantage of the rapid
application development capabilities available in Oracle Application Express to
enhance the generated pages. Built-in wizards also enable you to quickly expand your
new application by adding new pages and links as necessary.