Running a Program Under TCF › Using the UCE for Communication Under TCF

Using the UCE for Communication Under TCF

You use fields in the UCE:

• To communicate with TCF
• To communicate with other applications running under TCF

Communicating with TCF

When your program begins, it checks certain UCE fields to determine invocation conditions. You perform processing based on how your program is invoked.

When your program ends, it sets UCE fields to tell TCF what to do next; for example, whether to switch to another application, perform a pseudoconverse, suspend the TCF session, or end the TCF session.

Use the following fields in the UCE to communicate with TCF:

• UCE-IDENT-02 indicates whether your program is currently running under TCF. If it is, this field is equal to the value UMBR.
• UCE-SESSION-DESCR-02 is used as a queue or scratch record ID. Use this ID to retrieve the variable storage from your application's previously suspended TCF session.
• UCE-NEXT-TASK-02 specifies the task to which TCF should switch.
• UCE-CURR-TASK-FLAG-02 is the flag you set to indicate to TCF whether to suspend a session, end a session, or begin a pseudoconverse.
• UCE-NEXT-TASK-FLAG-02 is the flag you set to indicate to TCF and to other applications whether to begin a new session or restart an old session.
• UCE-MSG-CODE-02, UCE-RETURN-CODE-02, and UCE-MSG-TEXT-POINTER-02 are used to process errors under TCF.

Communicating with Other Applications

You can pass data to and receive data from other applications that run under TCF. For example, you could pass a schema name, a subschema name, syntax, or input parameters.

The UCE provides different fields for different kinds of data:

• To pass a schema name, use the UCE-SCHEMA-NAME-02 field. Optionally, include a version number by using the UCE-SCHEMA-VER-02 field.
• To pass a subschema name, use the UCE-SUBSCHEMA-NAME-02 field. Optionally, include a version number by using the UCE-SUBSCHEMA-VER-02 field.
• To pass large amounts of data (33 bytes or more), use the UCE-INPUT-POINTER-02 field. UCE-INPUT-LENGTH-02 specifies the input data length.

  You can also use the UCE-OUTPUT-POINTER-02 field. UCE-OUTPUT-LENGTH-02 specifies the output data length.

• To pass small amounts of data (32 bytes or less), use the UCE-ENTITY-OCCURRENCE-02 field. In some situations, you may need to include a version number by using the UCE-ENTITY-OCCUR-VER-02 field.