Chapter 1 Understanding Application Integrator for CICS

Jaguar and AI for CICS Functionality

The following sections describe how Jaguar functions and how it relates to AI for CICS:

• How Jaguar Works
• When Jaguar Uses AI for CICS Components

How Jaguar Works

Jaguar implements a "multi-tier" distributed computing architecture. Figure 1-3 shows the typical Jaguar environment, in which three distinct elements, or tiers, work together to allow users to access data:

• The client, which contains the applet or application code that manages the presentation and interaction with the end user.
• Middle-tier components, which run in Jaguar and are typically coded by the middle-tier developer. They contain the executable business logic that handles much of the application processing.
• The back-end database, which is the transaction target accessed by the Jaguar component. It stores, manages, and processes data.

In most cases, interaction between the client application and Jaguar occurs as follows:

1. When a client application needs to use a component, it issues a request to the Jaguar server.
2. The request from the client environment prompts Jaguar to instantiate the component.
3. The client application invokes a method on a component. The method executes, accesses a database, and possibly returns data to the client.

   For detailed information about how Jaguar works, see the Jaguar documentation.

When Jaguar Uses AI for CICS Components

When Jaguar uses AI for CICS components, the components in the middle tier are "proxies" that represent the CICS application program. The Jaguar environment is composed of the following elements, or tiers:

• The client, which contains the applet or application code that manages the presentation and interaction with the end user.
• Middle-tier AI for CICS components, which provide direct access to the CICS application program. No middle-tier coding is required.
• The CICS program, which contains business logic for an application.

Figure 1-4 shows the Jaguar client communicating with a CICS program through the AI for CICS component in the middle tier.

In most cases, interaction between the client application and Jaguar occurs as follows:

1. The Jaguar client application requests the component to be instantiated one of two ways.
   • If the Jaguar client is an applet, users can find and launch applications from traditional HTML pages. Instead of simply loading a static page, Jaguar downloads an executable applet to the user's browser.
   • If the Jaguar client is an installed application, users can launch the application from their machines.
2. Jaguar instantiates the component.
3. The client calls a method in the component.
4. The AI for CICS component invokes the CICS program and returns any result sets to the client application.

Copyright © 1999 Sybase, Inc. All rights reserved.