Introduction

The Z and I Emulator for Transformation (ZIETrans) Toolkit offers many tools for creating and customizing Web ZIETrans applications that provide an easy-to-use graphical user interface (GUI) for your character-based 3270 or 5250 host applications. ZIETrans Web applications can be developed with a look and feel that matches your company's Web, and your users can access them through their Web browsers. ZIETrans can also be used to create service-oriented architecture (SOA) assets from logic contained in your character based 3270, 5250, or VT applications.

Service-Oriented Architecture expresses a perspective of software architecture that defines the use of loosely coupled software services to support the requirements of the business processes and software users. In an SOA environment, resources on a network are made available as independent services that can be accessed without knowledge of their underlying platform implementation.

SOA can also be regarded as a style of Information Systems architecture that enables the creation of applications that are built by combining loosely coupled and interoperable services. These services operate together based on a formal definition or contract (for example, WSDL) that is independent of the underlying platform and programming language. The interface definition hides the implementation of the language-specific service. SOA-compliant systems can therefore be independent of development technologies and platforms (such as Java™ and .NET). For example, services written in C# running on .NET platforms and services written in Java running on Java EE platforms can both be consumed by a common composite application. In addition, applications running on either platform can consume services running on the other as Web services, which facilitates reuse. SOA can support integration and consolidation activities within complex enterprise systems, but SOA does not specify or provide a methodology or framework for documenting capabilities or services.

You might find that your ZIETrans application requires some additional function that you cannot add using the wizards and editors in ZIETrans Toolkit and IBM® Rational® Software Delivery Platform (SDP). This Web Application Programmer's Guide explains several ways that you can extend your ZIETrans application with additional programming. It also assumes that you are familiar with basic ZIETrans concepts such as:
  • How ZIETrans processes host screens
  • Creating a transformation using components and widgets
  • Events and actions
  • Using global variables
  • Recording a macro
  • Creating an Integration Object from a macro

If you are not already familiar with any of these topics, refer to the information about them in ZIETrans User's and Administrator's Guide so that you will have the necessary background to make good use of the information in this book. You should also be familiar with using Rational SDP to create Java EE applications.

This Web Application Programmer's Guide describes ways to enhance your ZIETrans application by programming. You can:
  • Add business logic classes to be invoked as an action when an event occurs. You can also create custom logic to aid in recognizing host screens. See Adding business logic for more information.
  • Add new host components or widgets to be used in transformations by extending the existing host components and widgets. See Creating custom components and widgets for more information.
  • Perform several programming tasks with Integration Objects.
  • Make one or more Integration Objects available as a Web service, which makes the objects available for use by other applications.
  • Create your own plug-ins for Web Express Logon.
  • Use the ZIETrans bidirectional API to work with the orientation of screen elements in applications that use bidirectional code pages. See Using the ZIETrans bidirectional API for more information.

When enhancing your applications, you might find that you need to edit some of the Java source files. Information provided in the section of the Rational Software Delivery Platform help titled Developing Java applications can help you with this task.