4D v16.3

CALL PROCESS

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4D v16.3
CALL PROCESS

CALL PROCESS 


 

CALL PROCESS ( process ) 
Parameter Type   Description
process  Longint in Process number

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 GET PROCESS VARIABLE and SET PROCESS VARIABLE commands.

Tip: CALL PROCESS accepts 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 post any outside call. 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.



See also 

Form event
GET PROCESS VARIABLE
SET PROCESS VARIABLE

 
PROPERTIES 

Product: 4D
Theme: Process (Communications)
Number: 329

Not for server

 
HISTORY 

Created: < 4D v6

 
ARTICLE USAGE

4D Language Reference ( 4D v16)
4D Language Reference ( 4D v16.1)
4D Language Reference ( 4D v16.2)
4D Language Reference ( 4D v16.3)