topic Re: Error handling by Add_from_instance method in Application Development and Automation Discussions

Error handling by Add_from_instance method

Former Member — Thu, 12 Apr 2007 05:14:00 GMT

Hello,

I would like to know how can we handle errors in ABAP OO by the add_from_instance method.

Kindly suggest your answers.

Regards,

Prerna.

Re: Error handling by Add_from_instance method

uwe_schieferstein — Thu, 12 Apr 2007 07:05:43 GMT

Hello Perna

I assume that you mean the instance method from interface IF_RECA_MESSAGE_LIST.

The logic is quite simple. Let's assume a scenario where you have a model instance (containing the business logic -> MVC model). This model instance creates instance of others classes (e.g. for sales orders, etc.). Thus, we have a composition of classes.

Both the model instance and the others instances (which are customer classes) have a message handler (of TYPE REF TO if_reca_message_list). The message handler is defines as public and read-only instance attribute.

Following is some sample coding which demonstates the logic:


" We are here in a method of the model instance. We access the message handler
" using me->msg_msglist.

" The model instance has a list of object instance (e.g. me->mt_orders).
" Before processing these orders the model instance has already added
" several messages (e.g. for validation) to its message handler.

" Now the model instance processes the order instances:

  LOOP AT me->mt_orders INTO ls_order.
"   While creating the order instance they have done themselves some validation
"   an added the message to their own message handler,
"   e.g. ls_order-instance->mo_msglist.

"   Now we add the messages from the order instances to the message handler
"   of the model instance.
    CALL METHOD me->mo_msglist->add_from_instance( ls_order-instance->mo_msglist).
"   NOTE: this method has an IMPORTING parameter which allows to add
"              the messages as subnode

  ENDLOOP.

Regards

Uwe

Re: Error handling by Add_from_instance method

Former Member — Thu, 12 Apr 2007 07:19:54 GMT

Hello,

I have a validation class which validates the data.

In the asmple logic, you have said that we have to collect these messages.

Kindly guide me as to how do I collect them.

Thanks,

Prerna

Re: Error handling by Add_from_instance method

uwe_schieferstein — Thu, 12 Apr 2007 08:00:30 GMT

Hello Prerna

Assuming that the methods of your validation class return the message by raising an exception you can collect the messages as following:

" 1st validation

CALL METHOD mo_myclass->validate_input1

EXPORTING

...

EXCEPTIONS

error = 1

others = 2.

IF sy-subrc <> 0.

MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.

" Here we collect the message that is returned in SYST

me->mo_msglist->add_from_symsg( ).

ENDIF.

" 2nd validation

CALL METHOD mo_myclass->validate_input2

EXPORTING

...

EXCEPTIONS

error = 1

others = 2.

IF sy-subrc <> 0.

MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.

" Here we collect the message that is returned in SYST

me->mo_msglist->add_from_symsg( ).

ENDIF.

Regards

Uwe