topic Re: about classes in Application Development and Automation Discussions

about classes

Former Member — Thu, 25 Jan 2007 11:34:09 GMT

hi any one help me how to declare class in abap ? like in c..

plz send simple example of it.

Re: about classes

SantoshKallem — Thu, 25 Jan 2007 11:37:01 GMT

go thru with sample

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.

Reward if useful.

cheers.

santhosh

Re: about classes

Former Member — Thu, 25 Jan 2007 11:37:52 GMT

Hi Rohan ,

Here is a sample class definition

CLASS L_CL_MATNR DEFINITION .
*--> Declare attributes of class
  PUBLIC SECTION .
    DATA : G_T_MATNR TYPE TABLE OF G_TY_MATNR ,
           G_WA_MATNR TYPE G_TY_MATNR.
    EVENTS : NO_DATA_FOUND.
    METHODS : GET_MATERIAL_DETAILS ,
              DISPLAY_OUTPUT,
              DISPLAY_ERROR FOR EVENT NO_DATA_FOUND OF L_CL_MATNR.

  PRIVATE SECTION.

*    METHODS :  display_error FOR EVENT no_data_found OF l_cl_matnr.

ENDCLASS.

*---------------------------------------------------------------------*
*       CLASS l_cl_matnr IMPLEMENTATION
*---------------------------------------------------------------------*
*       ........                                                      *
*---------------------------------------------------------------------*
CLASS L_CL_MATNR IMPLEMENTATION.
*--> Implement Method get material
  METHOD GET_MATERIAL_DETAILS .
    SELECT MATNR WERKS LGORT LABST
     INTO TABLE G_T_MATNR
     FROM MARD
     WHERE MATNR IN SO_MATNR AND
           WERKS IN SO_WERKS.
    IF SY-SUBRC <> 0.
      RAISE EVENT NO_DATA_FOUND.
    ENDIF.

  ENDMETHOD.

*--> Implement Method display_output
  METHOD DISPLAY_OUTPUT .


  ENDMETHOD.


*--> Implement Method display_error
  METHOD DISPLAY_ERROR .
    WRITE : 'error'.
  ENDMETHOD.

ENDCLASS.

so it has 2 parts one for DEFINITION and second for implementation.

Dont forget to reward points if reply is helpful.

Regards

Arun

Re: about classes

Former Member — Thu, 25 Jan 2007 11:38:44 GMT

try this link it will be very useful.....

regds,

kiran

Re: about classes

Former Member — Thu, 25 Jan 2007 11:40:48 GMT

hi,

Here is the sample program.

REPORT zmmr_nm_prd_ord_label .

SELECTION-SCREEN BEGIN OF BLOCK b1 WITH FRAME TITLE text-001.

PARAMETERS : p_werks TYPE werks_d ,

p_aufnr TYPE aufnr ,

p_tank TYPE char1 .

SELECTION-SCREEN END OF BLOCK b1.

*Class declaration.

CLASS prd_ord_label DEFINITION.

PUBLIC SECTION.

DATA : v_maktx TYPE matnr,

v_pdesc TYPE name2,

v_matnr TYPE matnr.

METHODS : get_data IMPORTING e_werks TYPE werks_d

e_aufnr TYPE aufnr,

print_label IMPORTING e_ab1 TYPE n

e_ab2 TYPE char20

e_werks TYPE werks_d

e_devic TYPE sypdest

e_date TYPE sy-datum.

ENDCLASS.

CLASS prd_ord_label IMPLEMENTATION.

METHOD get_data.

CLEAR : v_matnr, v_maktx, v_pdesc, it_charg,x_charg.

SELECT SINGLE plnbez FROM afko INTO v_matnr WHERE aufnr = e_aufnr.

SELECT SINGLE maktx FROM makt INTO v_maktx WHERE matnr = v_matnr.

SELECT SINGLE name2 FROM t001w INTO v_pdesc WHERE werks = e_werks.

SELECT charg FROM afpo INTO TABLE it_charg WHERE aufnr = e_aufnr.

ENDMETHOD.

METHOD print_labels.

DO 51 TIMES.

IF v_c1 < e_lb1.

v_c1 = v_c1 + 1.

CALL METHOD print_label EXPORTING e_ab1 = e_lb1

e_ab2 = e_lb2

e_werks = e_werks

e_devic = e_devic

e_date = e_date.

ENDIF.

ENDDO.

ENDMETHOD.

ENDCLASS.

START-OF-SELECTION.

DATA : o_prdlbl TYPE REF TO prd_ord_label.

CREATE OBJECT o_prdlbl.

CALL METHOD o_prdlbl->get_data EXPORTING e_werks = p_werks

e_aufnr = p_aufnr.

..........

...........

Hope this helps.

Regards,

Richa