Application Concepts › Application Components › Functions › Available System Functions

Available System Functions

The following system functions are available:

POP

Returns processing control to the previous menu in the application thread.

POPTOP

Returns processing control to the first menu in the application thread.

TOP

returns processing control to the highest function in the current application thread.

RETURN

Returns processing control to the next higher function in the current application thread.

Note: If a RETURN command is coded into a response process, it is considered a process command, not a system function. As a process command, RETURN performs as it would in an the DC/UCF system's environment.

HELP

Displays a HELP screen at run time. This screen lists all valid responses for the current function.

QUIT

Terminates processing of the current application. If previously signed on to the application, the user is automatically signed off.

SIGNON/SIGNOFF

Allows a user to signon or signoff. This is an CA IDMS/DC signon/signoff function executed from within the application.

FORWARD/BACKWARD

Allows a user to page forward or backward on menu maps.

System functions can be subdivided as follows:

• QUIT, POPTOP, POP, TOP, and RETURN are generally executed when an EXECUTE NEXT FUNCTION command is encountered.
• SIGNON, SIGNOFF, and HELP are always executed as soon as they are encountered by the runtime system.
• FORWARD and BACKWARD (menu functions only) are executed as soon as they are encountered. If associated with a nonmenu dialog function, the FORWARD and BACKWARD functions are moved into the ADSO-APPLICATION-GLOBAL-RECORD prior to executing the dialog's response process.
• User Program Functions are written in a process language other than CA ADS. When a user program function is activated, the CA ADS runtime system relinquishes control to the user program. CA ADS does not define valid responses for a user program; any responses made by the user must be processed by the executing user program. The runtime system maintains all buffers for the application at the level at which control was relinquished, anticipating return of the processing control.
• Internal Functions are associated with the current dialog function. An internal function is assumed to be a response defined for the dialog response process.
• The developer might define a response that initiates an internal function as a method of documenting the response process and/or as a method of providing the dialog response process as a valid response choice at run time. Additionally, a security class can be assigned to this type of response, thereby enabling security protection for a dialog's response process.