Using built-in system and object reference elements

ABL provides built-in system references and object reference elements to access instantiated class-based objects at run time. A built-in system reference (such as the THIS-OBJECT or SUPER system reference) returns a value set by ABL that represents a given class or class-based object depending on the class context where the reference occurs in an ABL session. A built-in object reference element (such as the FIRST-OBJECT attribute on the SESSION system handle) holds an object reference to a class-based object that is instantiated within the ABL session. The value of a built-in object reference element is automatically set by the AVM according to the function of the element.

The different built-in system references and object-reference elements are specified by keywords in ABL. The sections that follow describe these ABL elements.