IBM AS/400e, Руководство пользователя

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IBM Licensed Programs: Application Development Products
644
AS/400e System Handbook
This product was previously named VisualGen Host Services for OS/400.
This solution combines the best of both worlds: the productivity of an iterative desktop
development environment with the scalability and he performance of a compiled and
optimized 3GL production application.
To fully understand the power of VisualAge Generator, the rest of this description reviews the
primary design points of this technology to:
• Provide the highest level of programmer productivity
• Fulfill the demands of an enterprise environment
• Enable rapid deployment of Web-enabled e-business solutions
Programmer Productivity
To address the first primary design point of programmer productivity, VisualAge Generator is
equipped with four core facilities:
• Data model driven automatic code generation
Industry research shows that the majority of the code written to implement business
applications has nothing to do with the business problem. However this code is necessary
to establish the “mechanical” infrastructure of the system providing functions such as
handling error conditions, and keeping track of positioning within an array of data.
Using the VisualAge Generator Templates facility, developers can have the application
infrastructure (framework) automatically generated by the system. This dramatically
reduces the coding requirements and allows the developer to build a fully functional
database manipulation application in a matter of minutes.
Programmers will build the bulk of their application by simply defining instances of the
template's
Information Model . The definition consists of choosing the data to be
manipulated (tables, views and columns), and selecting how the data will be displayed.
This set of intuitive, and seemingly simple specifications, allows VisualAge Generator
Templates to automatically generate surprisingly comprehensive application code to:
– Access and manipulate database (Create, Read, Update, Delete)
– Present the data to the end user in different ways (Java or traditional GUI, JSP or TUI)
– Manage navigation among multiple windows and session state
– Manage multi-user data access concurrency
– Manage paging when data result set is larger than page size
– Manage error conditions
– Provide window and field level online help
Once this application framework is generated, developers simply add the business logic
using the standard VisualAge Generator specification facilities to complete the creation of
the system.