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Version: 7.0

DATA operator

The DATA operator creates a data property.

Syntax​

DATA [LOCAL [NESTED [MANAGESESSION | NOMANAGESESSION]]] returnClass [(argumentClass1, ..., argumentClassN)]

Description​

The DATA operator creates a data property. This property operator cannot be used inside expressions. The data property can be created local by specifying the keyword LOCAL.

For a local property, you can additionally specify NESTED. In this case, the property becomes nested, and its values are preserved during session-management operations. If no additional modifier is specified after NESTED, the property is treated as nested both when creating a new session and when managing the current session. The MANAGESESSION modifier keeps the nested behavior only for APPLY / CANCEL, while NOMANAGESESSION keeps it only for NEWSESSION.

This operator cannot be used in the JOIN operator (inside [ ]), since a name must be specified for the data property.

Parameters​

  • LOCAL

    A keyword that, when specified, creates a local data property.

  • NESTED

    A keyword that can only be used after LOCAL. It marks the local property as nested. Without additional modifiers, this means that the property is treated as nested both when creating a new session and during APPLY / CANCEL.

  • MANAGESESSION | NOMANAGESESSION

    Keywords that can only be used after NESTED.

    • MANAGESESSION means that the property is treated as nested only for operations that manage the current session (APPLY, CANCEL).
    • NOMANAGESESSION means that the property is treated as nested only when entering and leaving NEWSESSION.

  • returnClass

    Class ID of the return value of a property.

  • argumentClass1, ..., argumentClassN

    A list of class IDs for property arguments. An empty list (()) means the property has no arguments. Without the list at all, the argument classes are taken from the property declaration's typed parameters.

Examples​

CLASS Item;
quantity = DATA LOCAL INTEGER (Item);

sessionOwners = DATA LOCAL NESTED MANAGESESSION INTEGER ();

CLASS Order;
selected = DATA LOCAL NESTED NOMANAGESESSION BOOLEAN (Order);

CLASS Country;
isDayOff = DATA BOOLEAN (Country, DATE);