ABAP SET HANDLER INSTANCE Statement syntax and functionality in SAP

SET HANDLER - FOR

Short Reference

ABAP Syntax SET HANDLER handler1 handler2 ... FOR { oref |{ALL INSTANCES} }
[ACTIVATION act].

ABAP_ADDITIONS:
1 ... FOR oref
2 ... FOR ALL INSTANCES
3 ... ACTIVATION act

What does it do? This statement registers the event handlers handler1 handler2 ... for the associated instance events
of the objects specified after FOR . The addition
ACTIVATION can be used to deregister event handlers or perform a dynamic registration.
An event handler is executed if the associated instance event is triggered using RAISE EVENT in an object for which it is registered. An event handler handler can be specified as follows, where the names have the same meaning as in the explicit method call :
meth
oref- meth
class= meth
Methods meth can be specified from the same class or from other classes defined as instance event handlers using the addition FOR EVENT evt OF {class|intf} of the statements [CLASS-]
METHODS . No event handlers for static events can be specified. At least one name must be specified.
The type class or intf specified after FOR EVENT OF in the definition of an instance event handler defines the objects whose events it can handle. Single objects or all handleable objects can be specified after FOR .

ABAP_ADDITION_1 ... FOR oref

What does it do? This addition registers or deregisters the event handlers of the list handler1 handler2 ... for exactly one object. oref is an object reference that must point to an object whose events can be handled by the specified event handlers. The class of the object must be class or a subclass of class , or must implement the interface intf directly or through a superclass.
oref is a functional operand position .
Example ABAP Coding Registers an event handler for an ALV event.
CLASS demo DEFINITION.
PUBLIC SECTION.
METHODS main.
PRIVATE SECTION.
DATA itab TYPE TABLE OF scarr.
METHODS handle_double_click
FOR EVENT double_click OF cl_salv_events_table.
ENDCLASS.

CLASS demo IMPLEMENTATION.
METHOD main.
DATA alv TYPE REF TO cl_salv_table.
...
TRY.
cl_salv_table=>factory(
IMPORTING r_salv_table = alv
CHANGING t_table = itab ).
SET HANDLER handle_double_click FOR alv->get_event( ).
CATCH cx_salv_msg.
...
ENDTRY.
ENDMETHOD.
METHOD handle_double_click.
...
ENDMETHOD.
ENDCLASS.

ABAP_ADDITION_2 ... FOR ALL INSTANCES

What does it do? This addition registers or deregisters the event handlers of the list handler1 handler2 ... for all objects whose events they can handle. These are all objects whose classes are either
class or the subclass of class , or which implement the interface intf directly or through a superclass. A registration of this type is also valid for all triggering instances created after the statement SET HANDLER .

ABAP_ADDITION_3 ... ACTIVATION act

What does it do? A single-character text-like field act can be specified after the addition ACTIVATION . If act has a value "X" (default value), the event handlers handler are registered; however, if act has the value " ", the registration of the event handlers handler is canceled. A single registration cannot, however, be deregistered using mass deregistration. Conversely, individual triggering objects cannot be excluded from registration after a mass registration.
Latest notes: As long as the registration of an instance method as an event handler for an instance event is not canceled using ACTIVATION " " or all triggering instances are deleted, the associated object cannot be deleted by the garbage collector , since it is still used by the runtime environment.

ABAP SET HANDLER INSTANCE Statement syntax, information and example SAP source code