Figure 1 shows the control flow through the CICS® business
logic interface for a request for a terminal-oriented transaction. Note that
the business logic interface is running under a CICS mirror transaction, not a Web CICS transaction.
The first part of the processing is the same as for calling a program, but
if you want to run a transaction, you must specify DFHWBTTA as the CICS application
program to be called, in wbbl_server_program_name.
Figure 1. Running a transaction with the CICS business
logic interface—control flow
- If the caller requests a converter, the CICS business logic interface calls it,
requesting the Decode function. Decode sets up the COMMAREA for DFHWBTTA.
- The CICS business
logic interface calls DFHWBTTA. The COMMAREA passed to DFHWBTTA
is the one set up by Decode. If no converter program was called, the
COMMAREA contains the entire request.
- DFHWBTTA extracts the transaction ID for the terminal-oriented transaction
from the HTTP request, and starts a transaction that runs the CICS Web bridge
exit.
- When the program attempts to write to its principal facility, the data
is intercepted by the CICS Web bridge exit. The exit constructs the HTML response
which is returned to the CICS business logic interface. If the caller requested
a converter, the CICS business logic interface calls the Encode function
of the converter, which uses the COMMAREA to prepare the response.
If no converter program was called, the CICS business logic interface assumes that
the COMMAREA contains the desired response.