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News In Review

November 10, 1997

Get A Passport To The Internet

Passport IntRprise 1.1 is a RAD tool for multitier, enterprise development

By Jay Tyo

D evelopers looking to build large-scale applications that span many databases and platforms and hundreds of users may have a tough time finding the right tool for the job. Many of the popular personal and client-server tools are based on a two-tier architecture and don't scale well to more complex environments. Building an enterprise application for both the client-server and Internet worlds makes finding the right tool even more difficult. Passport Corp.'s Passport IntRprise 1.1 is a multitier and Internet-capable application-development tool that should meet your needs.

Passport IntRprise is built on top of Passport's object-oriented fourth-generation language (4GL), called Passport. That language is built on top of C. IntRprise supports all of the most popular relational databases, graphical user interface-based rapid application development (RAD), message-oriented middleware (MOM), and team development; it lets users take an application written for one platform and port it to another platform, including the Internet, by relinking it with the appropriate libraries. With these features, its price tag of almost $9,000 per developer seat, and run-time charges for the MOM, IntRprise is clearly targeted at the enterprise development tool market.

First-generation Web applications sent HTML pages across the World Wide Web to browsers. This is great technology for displaying static information, but falls short for serious Internet applications. HTML applications tend to be heavy network users, although they offer little interactivity. The second generation of Web applications downloads Java applets to Web browsers. This works great for small applications, but when the applications are large, download times can be prohibitive. And since Java is an interpreted language, application processing is slower than for apps written with compiled la nguages.

Passport has come up with a new technology, called Java Presentation Protocol (JPP), that lets large applications run over the Internet. With JPP, the application runs on the server and displays the output on the client PC. Only display changes are sent over the network. This greatly reduces network traffic and improves user response time. I tested this from a user's perspective by running an application from Passport's Web site. The application screens loaded from the Web site quickly and ran as if they were local to my machine.

JPP consists of various components installed on both the server and the client. The only components required for the client are the Java Virtual Machine (JVM), and Passport's Java Presentation Applet (JPA). The JPA comes with the development tool and is also freely downloadable from Passport's Web site.

The server side of JPP has three components: Java Presentation Agent, a dedicated messaging server, and the application, which is compiled C code. The application runs on the server at speeds befitting a compiled application and uses the JPA and the messaging server to communicate the changing window information to the client's JPA.

JPP does have some drawbacks. For each user, the application is running on the server. If the developer is not careful, the server load could grow right along with the growth in concurrent users.

Another drawback comes with the current implementations of Java. IntRprise uses version 1.0.2 of the Java Development Kit (JDK), which does not support some features common to GUI applications such as screen fonts, colors, some mouse actions, and scrolling behaviors. Most of these considerations will go away just as soon as the browser vendors standardize their Java 1.1 implementations.

Relatively Easy
The process of developing with Passport IntRprise is relatively simple given the power and complexity of the tool. IntRprise is made up of several visual tools, each designed for a portion of the development task. The Workbe nch is used to define the application and launch the other tools. The developer then defines the database to IntRprise with the Entity Attribute Editor. After IntRprise knows about all the databases the application will access, the developer launches RapidApp-IntRprise's RAD tool. Here the developer defines the application screens and chooses the data that drives them from the databases available.

Once the basic screens are defined, the developer can modify the objects-fields, labels, buttons-on the screen with the Visual Object Editor. Passport IntRprise supports incremental compilation, which allows the developer to incrementally test the screens and data without having to do a full compile. When modifying the logic associated with the objects on the screen, the developer uses the Visual Logic Editor.

All of the tools generate Passport code, which is stored in files on the developer's machine. There are separate files for the objects and for the logic. This allows the developer to look at the code t hat the tools generated and make any manual changes desired. For simple applications this can be kept to a minimum, but for the more complex applications Passport is targeting, developers will need to spend significant time hand-coding in the Passport language.

One of the most powerful features of Passport IntRprise is support for multitier applications via the built-in MOM. Passport bundles in Momentum's X*IPC, though it also supports BEA Systems' Tuxedo and will soon support IBM's MQSeries products.

X*IPC allows the developer to build a business logic server to communicate asynchronously between the database server and the client. This type of peer-to-peer communications provides guaranteed message delivery and allows multiple copies of the business server to balance the load for large numbers of concurrent users.

After the application is developed, the Passport code is parsed into C and is compiled as any C application would be. IntRprise lets developers build applications on and for all Micr osoft Windows versions, and 16 versions of Unix. Additionally, applications may be ported to VAX/VMS as well as to the Internet. Platform choice can be made at deployment time. The developer simply compiles and links the application on the target platform. For JPP, the developer needs to select a radio button to indicate that the Java windowing libraries should be linked in.

For corporate developers who want to build true enterprise applications, Passport's IntRprise is a good tool. The combination of an easy-to-use developer interface, solid messaging that supports n-tier applications, and an interesting method of supporting Internet and intranet applications and thin clients makes Passport IntRprise a good choice for serious corporate users.

Jay Tyo is an analyst with Rochester Gas and Electric in Rochester, N.Y. He can be reached at tyo@rge.com .


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