Reports |
The report driver retrieves data, starts the report engine and sends the data (as input records) to be formatted by the REPORT routine.
A report driver can be part of the MAIN program block, or it can be in one or more functions.
The report driver typically consists of a loop (such as WHILE , FOR, or FOREACH) with the following statements to process the report:
Instruction | Description |
---|---|
START REPORT | This statement is required to instantiate the report driver. |
OUTPUT TO REPORT | Provide data for one row to the report driver. |
FINISH REPORT | Normal termination of the report. |
TERMINATE REPORT | Cancels the processing of the report. |
A report driver is started by the START REPORT instruction. Once started, data can be provided to the report driver through the OUTPUT TO REPORT statement. To instruct the report engine to terminate output processing, use the FINISH REPORT instruction. To cancel a report from outside the report routine, use TERMINATE REPORT (from inside the report routine, you cancel the report with EXIT REPORT).
In order to handler report interruption, the report driver can check if the INT_FLAG variable is TRUE to stop the loop when the user asked to interrupt the report execution.
It is possible to execute several report drivers at the same time. It is even possible to invoke a report driver inside a REPORT routine, which is different from the current driver.
The programmer must make sure that the runtime system will always execute these instructions in the following order:
SCHEMA stores7 MAIN DEFINE rcust RECORD LIKE customer.* DATABASE stores7 DECLARE cu1 CURSOR FOR SELECT * FROM customer LET int_flag = FALSE START REPORT myrep FOREACH cu1 INTO rcust.* IF int_flag THEN EXIT FOREACH END IF OUTPUT TO REPORT myrep(rcust.*) END FOREACH IF int_flag THEN TERMINATE REPORT myrep ELSE FINISH REPORT myrep END IF END MAIN