4D Doc Center : CALL PROCESS

4D v13.4

CALL PROCESS


CALL PROCESS ( process )

Parameter	Type	Description
process	Longint	Process number

Description

CALL PROCESS calls the form displayed in the frontmost window of process.

Important: CALL PROCESS only works between processes running on the same machine.

If you call a process that does not exist, nothing happens.

If process (the target process) is not currently displaying a form, nothing happens. The form displayed in the target process receives an On Outside call event. This event must be enabled for that form in the Design environment Form Properties window, and you must manage the event in the form method. If the event is not enabled or if it is not managed in the form method, nothing happens.

Note: The On Outside call event modifies the entry context of the receiving input form. In particular, if a field was being edited, the On Data change event is generated.

The caller process (the process from which CALL PROCESS is executed) does not “wait”— CALL PROCESS has an immediate effect. If necessary, you must write a waiting loop for a reply from the called process, using interprocess variables or using process variables (reserved for this purpose) that you can read and write between the two processes (using GET PROCESS VARIABLE and SET PROCESS VARIABLE).

To communicate between processes that do not display forms, use the commands GET PROCESS VARIABLE and SET PROCESS VARIABLE.

CALL PROCESS has the alternate syntax CALL PROCESS(-1).

In order not to slow down the execution of methods, 4D does not redraw interprocess variables each time they are modified. If you pass -1 instead of a process reference number in the process parameter, 4D does not call any process. Instead, it redraws all the interprocess variables currently displayed in all windows of any process running on the same machine.

Example

See example for On Exit database method.