> Writing Host Command Syntax

HOST commands initiate user exits, which initiate the external applications. The syntax of the HOST command is the same as the syntax used when initializing a program from the command line. When issuing a user exit command, Datastream 7i uses data stored in parameters and data displayed on screen to initialize the application. To use this data, the HOST command must contain the relevant substitution parameters.

The following substitution parameters are available. Substitution parameters have a $ prefix. Datastream 7i parameters have a $P prefix. When referencing attributes on the screen, use the $A prefix. Use the $F prefix when referencing a path/file.

Parameter Reference

Prefix

Datastream 7i

$P

Attributes on the screen

$A

Path/file

$F

The following parameters are available:

Parameter

Description

PERMISSIONS

The permissions

GROUP

The user group code, e.g., Datastream 7i

R5USER

The code of the current user, e.g., USR102

LANGUAGE

The language code of the user, e.g., EN

THIS_FUNCTION

The code of the Datastream 7i function, e.g., OMOBJC

R5SESSION

The Datastream 7i session ID, e.g., 5508921

FUN_RENTITY

The EN entity code of the screen, e.g., OBJ

When the external application requires a user code, the HOST command is (where $F indicates the executable to start)

MyProg $P.R5USER or $F $P.R5USER

The HOST command requires the R5SESSION parameter if the external application returns commands back to Datastream 7i. When the focus is back in Datastream 7i, it uses its session ID for retrieving any messages that the external application issues. For this example, the HOST command is

MyProg $P.R5SESSION $P.R5USER.

Send field contents to the external application. For example, when starting an external application from the Equipment form (OMOBJC) and sending the equipment code, the HOST command is MyProg $A.B1.OBJ_CODE. If field B1.OBJ_CODE is empty, or if the field is not available on the screen, a blank would replace the substitution string $A.B1.OBJ_CODE. Datastream 7i would not issue an error message.

This field function enables you to define User Exits that can call external applications. For example, if you want to check a part code on the Part form (SMPART) and also check that code when it is used on the Equipment form (OMOBJC), the HOST command is

MyProg $A.B1.PAR_CODE $A.B1.OBJ_PART.

On the Parts form (SMPART), $A.B1.OBJ_PART would be empty, and on the Equipment form (OMOBJC), $A.B1.PAR_CODE would be empty.

Datastream 7i issues an Oracle error when you misspell a parameter or reference a nonexistent parameter.