Getting Started-JetNet

The service component that you saved in Lesson 7 contains service routines that display data on the client screen and allow the client to update the database. In Lesson 4, you defined a service, test, in the JIF, and identified the service routine and service component.

All services must be defined for your application in the JIF, an interface file that maps each service name to a service routine and component. The JIF also defines other attributes of a service, such as its input and output requirements.

In general, the JIF is accessed for these reasons:

• A server is activated and checks the JIF to determine which services to advertise.

• A client issues a service call. The JIF provides service parameter attributes—types, number, and direction, and verifies the validity of the service call.

• A server receives a service request and its data, either directly from a client screen or forwarded from another service. The server consults the JIF to find the service routine and its service component (if any).

• The JIF is modified; all active servers are notified of the change and check the JIF in order to readvertise their services.

If service components were created with the screen wizard, you must update the JIF with definitions of the services that are associated with that service component. The JIF has its own editor which lets you access those service definitions and edit them, or add new definitions for services that you create yourself.

In this lesson you learn how to:

• Invoke the JIF editor.

• Define services for a wizard-based screen that fetch, add, delete and update distributor's orders.

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1. If necessary, reactivate the application from the server machine (refer to page 1-15 for UNIX and refer to page 1-28 for Windows).

You can add and update services while you are using the editor by invoking the JIF editor.

2. Invoke the JIF editor by doing one of the following, depending on your platform:

   UNIX: Start the editor, and choose ToolsJIF Editor.

   • Choose FileOpenMiddleware Session.

     Windows: From the Start Menu, choose ProgramsPanther ClientTutorialTutorial JIF Editor.

   • The Connect dialog box opens and displays the information you provided in your Windows initialization file (jifedtut.ini).
     

3. Enter any needed information, and choose OK.

   If the information is correct, that is, if it matches the entries you made in your server setup, you are connected to the middleware and the JIF editor workspace opens. The View Services dialog box is displayed showing the test service you defined (Lesson 3) in the jif.bin from the remote common.lib.

   Note: (Windows only) If you did not set the SMFLIBS variable in the jifedtut.ini to open the remote common.lib (host!common.lib), choose FileOpenRemote Library and select the remote common.lib that resides in the proltut directory. Choose FileOpenJIF and select the jif.bin library member.

   

   If the connection to the middleware is invalid or is not made, the JIF editor opens, but you will not have access to common.lib on the application server. In addition, updates to the JIF will not take effect and new services will not be advertised since the server won't know of the changes.

   Determine the correct host name (SMRBHOST) and port value (SMRBPORT), and under UNIX, the broker.bin (SMRBCONFIG) location. Try connecting to the middleware by entering the correct values in the Connect dialog box.

Define services to carry out basic database transaction requests. For the screen you just created with the screen wizard, you want to define services that let users add, update, select, and delete distributor records.

4. Choose ServiceCreate or .

   The Create Service dialog box opens.

   

5. Enter distributor_d in the Service Name field and press TAB.

   The JIF editor supplies the routine name, in this case delete, because of the _d suffix in the Service Name. It also provides a default service component name—using the prefix of the service name.

6. Press TAB to advance to the Service Component field.
7. Change the service component name to dstord (to match the name you provided in the editor when you saved the service component to server.lib).
   

8. Choose Add.

   The fields clear so that you can create another service.

More About Service Options

There are additional service specifications you can define in the JIF that let you control such things as:

• Which transaction a service implements.

• When a service component is opened and cached to memory.

• Behavior of the service itself when it is called.

By default, the JIF uses the service name to determine the transaction type; therefore, a service name that ends with _i sets the service to the transaction manager Insert operation. In addition, the Cache Service Component option by default is set to open or cache a service's service component when the service is advertised by the server.Repeat steps 5 through 8 for each of the other services: distributor_i, distributor_s, and distributor_u. Remember to provide the correct name of the service component, dstord.

9. Repeat steps 5 through 8 for each of the other services: distributor_i, distributor_s, and distributor_u. Remember to provide the correct name of the service component, dstord.
10. After you create all four services, choose Close to close the Create Services dialog box.

    The View Services dialog box displays the services you created.

    

11. Choose FileSave or .

    Since you are connected to the middleware, servers are notified immediately when changes are saved to the JIF. In addition, new services (depending on the advertise specification and if the server is configured to advertise all services) are advertised and immediately available to your application.

12. Choose FileExit.

    You are prompted to release the reservation on the JIF since it is stored in a remote library and is shared by others.

    

13. Choose Yes to release the reservation.

    The JIF editor closes.

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In this lesson, you invoked the JIF editor and:

• Created services devised by the screen wizard for your distributor/orders service component.

• Defined services that will be called by the client to select, update, insert, and delete distributors and their orders.

What did you learn?

You learned:

• The JIF stores service definitions.

• The JIF is accessed by client and server to determine what parameters and information should be used when processing service calls.

• The JIF editor can be invoked while you are working in the editor.

• When you are connected to the middleware, new and changed services are advertised by the server and are immediately available to your application.

• When you edit a jif.bin that is shared by the entire development team, you hold a reservation on that file.