ABAP_to_the_Future

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ABAP in Eclipse
(how the TYPE is chosen is black magic), or you can say that the variable is an
IMPORTING or CHANGING (or whatever) parameter, and then the method signature
in the class definition is changed accordingly.
1.2.7 Creating Class Constructors
A common object-oriented rule is that you should never create objects using the
CREATE OBJECT statement; rather, you should ha ve a factory method that gives
you the object. The advantage of this is that if your class variable is referenced to
an interface rather than a concrete class, then the factory method will decide the
exact subclass for you, which makes the program more resistant to change.
In ABAP in Eclipse, if you put yourcursor on the class name and press (CTRL) + (1)
then you get assorted options, including creating the factory method, creating a
class constructor, or creating an instance constructor (Figure 1.17).
Figure 1.17 Automatically Generating a Constructor
Moreover, if you have declared some variables in the class definition before you
do this, then a wizard pops up and asks you which of these variables you want to
have as IMPORTING parameters in the constructor. Therefore, if you had member
variables for a logging class and the in ventor name, for example, which you
wanted passed in every time a new instance was created, you would choose them
from the list presented. The generated result would look like Listing 1.12.
CLASS zcl_monster DEFINITION.
CONSTRUCTOR IMPORTING i_logger TYPE REF TO zcl_bc_logger
i_inventor_name TYPE zde_inventor_name.
CLASS zcl_monster IMPLEMENTATION.
METHOD constructor.
Super->constructor( ).
me->logger = i_logger.
me->inventor_name = i_inventor_name.
ENDMETHOD.
Listing 1.12 Automatically Generated Constructor
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