General syntax of DEFINE DATA INDEPENDENT:
DEFINE DATA |
INDEPENDENT
AIV-data-definition...
|
END-DEFINE |
This document covers the following topics:
For an explanation of the symbols used in the syntax diagrams, see Syntax Symbols.
The DEFINE DATA INDEPENDENT statement is used to define
application-independent variables (AIVs).
An application-independent variable is referenced by its name, and its
content is shared by all programming objects executed within one application
that refer to that name. The variable is allocated by the first executed
programming object that references this variable and is deallocated by the
LOGON command or a
RELEASE
VARIABLES statement.
The optional INIT
clause is evaluated in each executed programming object that contains this
clause (not only in the programming object that allocates the variable).
Note:
In an RPC server, application-independent variables (AIVs) are not
deallocated implicitly, but stay active across RPC requests, because different
clients may have access to the same variables on the RPC server. This means
they must be deallocated explicitly using the
RELEASE
VARIABLES statement. See
Application-Independent Variables
in the Natural Remote Procedure Call documentation.
| INDEPENDENT AIV-data-definition |
The |
|---|---|
| END-DEFINE |
The Natural reserved word |
| level |
|
variable-definition |
|
| redefinition | |||
| handle-definition |
Syntax Element Description:
| level | An application-independent variable must be defined at Level 01. Other levels are only used in a redefinition. |
|---|---|
| variable-definition |
A variable definition is used to define a single field/variable that may be single-valued (scalar) or multi-valued (array). See Variable Definition. Note: |
| redefinition |
A redefinition may be used to redefine a group, a view, a DDM field or a single field/variable (that is a scalar or an array). See Redefinition. The fields resulting from the redefinition must not be application-independent variables, that is their name must not start with a plus (+). These fields are treated as local variables. |
| handle-definition | A handle identifies a dialog element in code and is stored in handle variables. See Handle Definition. |
Note:
The first character of the name must be a plus (+). Rules for
Natural variable names apply, see
Naming Conventions for User-Defined
Variables in the Using Natural documentation.
