Template for making a class
Delete the parts that should not be used
******************************************
* Definition part
******************************************
CLASS xxx DEFINITION.
*------------------------------ * Public section*------------------------------
PUBLIC SECTION.
TYPES:
DATA:
* Static data
CLASS-DATA:
* Methods
METHODS:
* Using the constructor to initialize parameters
constructor IMPORTING xxx type yyy,
* Method with parameters
mm1 IMPORTING iii TYPE ttt.
* Method without parameters
mm2.
* Static methods
CLASS-METHODS:
*---------------------------------------------------* * Protected section. Also accessable by subclasses *--------------------------------------------------- PROTECTED SECTION.
*--------------------------------------------------- * Private section. Not accessable by subclasses *--------------------------------------------------- PRIVATE SECTION.
ENDCLASS.
******************************************
* Implementation part
******************************************
CLASS lcl_airplane IMPLEMENTATION.
METHOD constructor.
ENDMETHOD.
METHOD mm1.
ENDMETHOD.
METHOD mm2.
ENDMETHOD.
ENDCLASS.
Template for calling a class
* Create reference to class lcl_airplane
DATA: airplane1 TYPE REF TO lcl_airplane.
START-OF-SELECTION.
* Create instance using parameters in the cosntructor method
CREATE OBJECT airplane1 exporting im_name = 'Hansemand'
im_planetype = 'Boing 747'.
* Calling a method with parameters
CALL METHOD: airplane1->display_n_o_airplanes,
airplane1->display_attributes.
Subclass
CLASS xxx DEFINITION INHERITING FROM yyy.
Using af class as a parameter for a method
The class LCL_AIRPLANE is used as a parameter for method add_a_new_airplane:
METHODS:
add_a_new_airplane importing im_airplane TYPE REF to lcl_airplane.
Interfaces
In ABAP interfaces are implemented in addition to, and independently of classes. An interface only has a declaration part,
and do not have visibility sections. Components (Attributes, methods, constants, types) can be defined the same way as in classes.
· Interfaces are listed in the definition part lof the class, and must always be in the PUBLIC SECTION.
· Operations defined in the interface atre impemented as methods of the class. All methods of the interface must be present in the implementation part of the class.
· Attributes, events, constants and types defined in the interface are automatically available to the class carrying out the implementation.
· Interface components are addressed in the class by <interface name>~<component name>
Example of how to implement an interface:
INTERFACE lif_document
DATA: author type ref to lcl_author.
METHODS: print,
display.
ENDINTERFACE.
CLASS lcl_text_document DEFINITION.
PUBLIC SECTION.
INTERFACES lif_document.
METHODS display.
ENDCLASS.
CLASS lcl_text_document IMPLEMENTTION.
METHOD lif_document~print.
ENDMETHOD.
METHOD lif_document~display
ENDMETHOD.
METHOD display.
ENDMETHOD.
ENDCLASS.
REPORT zzz.
DATA: text_doc TYPE REF TO lcl_document.
Start-of-selection.
CREATE OBJECT text_doc.
CALL METHOD text_doc->lif_document~print.
CALL METHOD text_doc->lif_document~display.
CALL METHOD text_doc->display.
Events
For events of controls, refer to How to use controls.
· Events can only have EXPORTING parameters
· When an event is triggered, only those events handlers that have registered themselves using SET HANDLER by this point of runtime are executed. You can register an event using ACTIVATION 'X' and derigert it by using ACTIVATION 'SPACE'.
Defining events:
CLASS <classname> DEFINITION.
EVENTS: <event> EXPORTING VALUE (<ex_par>) TYPE type.
CLASS <classname> IMPLEMENTATION.
METHOD <m>:
RAISE EVENT <event> EXPORTING <ex_par> = <act_par>.
Handling events:
CLASS <classname> DEFINITION.
METHODS: <on_event> FOR <event> OF <classname> ! <interface> IMPORTING <imp_par1>...<imp_parN> SENDER.
Setting handler
SET HANDLER <ref_handle> <on_event> FOR <ref_sender> ! FOR ALL INSTANCES
[ACTIVATION <var>]