ABAP OO - Class cl_bcs

[Former Member]

Hi,

I'm quite new to abap oo but...anyway:

I get a exception when I try to call

• call method lo_bcs->set_sender

1. Any pointers to why this code doesn't work.

2. Why can't I do a CREATE OBJECT on lo_bcs.

method SETADDRESS_TO_FROM .

data: lo_sender type ref to if_sender_bcs.

data: lo_bcs type ref to cl_bcs.

*CREATE OBJECT lo_bcs. DONT WORK!!!?

try.

lo_sender = cl_cam_address_bcs=>create_internet_address( i_address_string = '[email protected]' ).

catch cx_address_bcs.

exit.

endtry.

TRY.

call method lo_bcs->set_sender

exporting

i_sender = lo_sender.

CATCH CX_SEND_REQ_BCS .

ENDTRY.

endmethod.

//Martin

[athavanraja]

You may want to check out this weblog where cl_bcs is class use is demonstrated.

/people/thomas.jung3/blog/2004/09/08/sending-e-mail-from-abap--version-610-and-higher--bcs-interface

Regards

Raja

[Former Member]

Hi,

I have read it.

This is more a OO question...

//Martin

[athavanraja]

data: mybcs type ref to CL_BCS ,

send_request type ref to CL_SEND_REQUEST_BCS .

TRY.

CREATE OBJECT mybcs

EXPORTING

i_send_request = send_request

.

CATCH cx_send_req_bcs .

ENDTRY.

Did you miss the mandatory parameter(i_send_request ) for the constructor.

Regards

Raja

[Former Member]

Thx getting there....

Error: "You cannot creat an instance of the class " CL_BCS" outisde the class.

Any Pointers?

//Martin

[athavanraja]

check out these programs.

BCS_EXAMPLE_1

BCS_EXAMPLE_2

BCS_EXAMPLE_5

Regards

Raja

[Former Member]

Hello Martin,

Okay, I think I get what you're saying now. If you see the attributes of the class CL_BCS, The Instantiation is supposed to be Private. which means that this class cannot be instantiated outside itself.

Does that sufficiently answer your question?

Regards,

Anand Mandalika.

[Former Member]

Hi,

Thx....I see...

Is this a common approach in the abap oo world ?.

Looks strange....why do they do this?

1. Looking at other examples I can see that I need to use the method CREATE_PERSISTENT in order to make o instance of this class CL_BCS. But how should I know this?

//Martin

[Former Member]

Hello Martin,

If the Instantiation for the class is defined to be <i>Private</i>, then you

cannot create the object of the class outside of the class.

=============================================================================

You have asked: <i>Is this a common approach in the abap oo world ? </i>.

There's nothing common or uncommon about it. It depends on what functionality

needs to be achieved.

=============================================================================

<i>Looks strange....why do they do this?</i>

In Java, you can actually make the constructor as private. In ABAP, however,

that is not possible. So this is another way of achieving equivalent

functonality.

=============================================================================

Now you'd like to know <i>Why do they do this...?</i>

That is a reasonably big discussion and cannot possible be explained satisfactorily

in a Forum Post. but I can tell you something: This way of disallowing external

instantiation for a class is the key to implementing OO Design Patterns.

As I had said, you can easily find other weblogs and Forum posts which can introduce

you to what these are.

Regards,

Anand Mandalika.

[sergey_korolev]

One of the aim of CREATE PRIVATE (among others) is to implement single-instance approach. E.g. you can declare some variable as static and provite and keep in it the single intstance of the class.