EVENTS
Short Reference
ABAP Syntax EVENTS evt [EXPORTING
parameters ].
ABAP_ADDITION:
... EXPORTING parameters
What does it do? Declares an instance event evt in a class or
interface. The Naming conventions apply
to the name evt . Using the RAISE EVENT
statement, the instance event evt can be raised in any
instance method of the same class, or of any class that implements the
interface, as well as in the instance methods of subclasses - if they
are visible there.
ABAP_ADDITION ... EXPORTING parameters
What does it do? The EXPORTING addition defines the parameter
interface of the event evt . An event can only have output
parameters parameters that are
passed by value.
When you declare an event handler
with the addition FOR EVENT OF of a
METHODS or
CLASS-METHODS statement,
the output parameters of the event are defined as the input parameters
of the event handler. The properties of the input parameters are copied
across from the output parameters defined in EVENTS .
As well as the output parameters defined explicitly using
EXPORTING , each instance event has an implicit output parameter,
sender . This output parameter has the type reference variable.
When the event is raised using RAISE EVENT , the reference to the
raising object is implicitly assigned to sender .
The static type of the input parameter sender is defined for
every event handler by the object type (class or interface) that is
specifed after the FOR EVENT OF of the METHODS or
CLASS-METHODS statement.
Latest notes: The dynamic type of the implicit formal parameter
sender is always the class of the object in which the event is
raised.
Example ABAP Coding In the interface window , three events are
declared, each with an explicit non-optional output parameter status
. The class dialog_window implements the interface window
. The interface window_handler contains
event handlers , which import both the
explicit parameters and the implicit parameter sender . The static
type of the input parameter sender is the class dialog_window
.
INTERFACE window.
EVENTS: minimize EXPORTING VALUE(status) TYPE i,
maximize EXPORTING VALUE(status) TYPE i,
restore EXPORTING VALUE(status) TYPE i.
ENDINTERFACE.
CLASS dialog_window DEFINITION.
PUBLIC SECTION.
INTERFACES window.
ENDCLASS.
INTERFACE window_handler.
METHODS: minimize_window
FOR EVENT window~minimize OF dialog_window
IMPORTING status sender,
maximize_window
FOR EVENT window~maximize OF dialog_window
IMPORTING status sender,
restore
FOR EVENT window~restore OF dialog_window
IMPORTING status sender.
ENDINTERFACE.
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