BC170_2.09.1

Modularization Techniques

BC170_2.09.2

Objectives

• The participants will be able to:

–

Create Subroutines

–

Describe the various methods for passing
Parameters to Subroutines

–

Create Function Modules

–

Call Function Modules from ABAP
Programs

BC170_2.09.3

REPORT YDEMOSB8.

Call calculated_tax

Call calculated_tax

Subroutine
Calculated_tax

Calculate tax

Calculate tax

REPORT YDEMOSB7.

What Are Subroutines

BC170_2.09.4

Modularization

REPORT YDEMOSB1.

Form sub

ABAP Function Builder

Function module
ZZCALC

REPORT YDEMOSB2.

Perform sub(YDEMOSB1

)

REPORT YDEMOSB1.

Perform sub

Form sub

REPORT YDEMOSB3.

Call Function ZZCALC

External
Call

FunctionMod
ule
Call

BC170_2.09.5

99

1

a1

a2

a3

Call Calculate_tax

Transfer values of fields a1 a2

Get value of field a3

Actual parameters a1 a2 a3

Formal parameters f1 f2 f3

Subroutine calculate_tax

99 1
f1

f2

f3

f3 = f1 +f2

. . . .

Actual / Formal Parameters

Parameter transfer

Parameter transfer

Main

Main

Program

Program

Subro

utine

Subro

utine

BC170_2.09.6

a1

a1

f1

f1

Subroutin

e

Pass by Value and Result

Pass by Value and Result

Subro

utine

Pass by Value

Pass by Value

a1

a1

f1

f1

Subro

utine

Pass by

Pass by

Reference

Reference

a1

a1

f1

f1

Methods of Passing Parameters

BC170_2.09.7

REPORT Y170D091.

TABLES: ....

DATA: .…

.

.

.

PERFORM

<name> USING

<a1> <a2>

<a3> <a4>.
.

.

.

FORM <name> USING

VALUE(<f1>)

VALUE(<f2>)
<f3>

<f4>.

ENDFORM.

Declaring and Calling a

Subroutine - Pass by Value(1) &

Reference(2)

Pass by reference

Pass by value

BC170_2.09.8

Pass by value

Declaring and Calling a

Subroutine - Pass by Value and

Result(3)

REPORT YSDEM000.

TABLES: ... .

DATA: ... .

.

.

.

PERFORM

<name> USING

<a1> <a2>

CHANGING<a3>.

.

.

.

FORM

<name> USING

VALUE(<f1>)

VALUE(<f2>)

CHANGING VALUE(<f3>).

.

.

.

f 3 =“A”.

.

.

.

ENDFORM.

Pass by value and result

BC170_2.09.9

Global versus Local Data

report

y170dm86.

data: num(9) value ‘999999999’.

data:

cust_id like kna1-kunnr,
name like kna1-name1.

. . . <statements>
perform sub1.
. . . <statements>

* --------------------------------------------------------------------------------- ----------------*
*

FORM SUB1

*

* ------------------------------------------------------------------------------------------------------------------------------------- -----------------*

form sub1.
data: begin of tab occurs 10,

“ <----------- local data

cust_id like kna1-kunnr,
name1

like kna1-name1,

end of tab.

local: num

.

“ <----------- local data

. . . <statements>
endform.

Global Data

Local Data

BC170_2.09.10

Statement Value Upon Entering Value Upon Value

Upon Entering

between Subroutine First Time Returning to

Subroutine Next

FORM…

Main Program

Time

ENDFORM

DATA

Whatever the local If declared Re-

initializes based

DATA statement globally, returns on local

DATA

initializes

to old value,

statement

otherwise not

recognized

STATICS Whatever the local If declared Last set

value from

STATICS statement globally, returns inside

subroutine

initializes

to old value,

otherwise not

recognized

LOCAL

Last set value from Last set value Last set

value from

main program from main main

program

program

Local Data in Subroutines

BC170_2.09.11

REPORT Y170D095.
TABLES: KNA1.
DATA: ZTAB LIKE KNA1.
DATA: FLAG.

.

.

PERFORM SUB1 USING KNA1.
PERFORM SUB1 USING ZTAB.

.

.

.

Passing Structures as

Parameters

FORM SUB1 USING

REC STRUCTURE KNA1.

WRITE: / REC-LAND1,

REC-NAME1.

ENDFORM.

This is passing the

KNA1 work area only

This is passing

the ZTAB

structure

BC170_2.09.12

Passing Internal Tables as

Parameters

REPORT Y170D093.
DATA : BEGIN OF TAB OCCURS 10,
F1 LIKE KNA1-LAND1,
F2 LIKE KNA1-NAME1,

.

.

.
END OF TAB.
DATA : X.

.

.

.
PERFORM SUB1 TABLES TAB
. USING X.

.

.

FORM SUB1

TABLES FRED STRUCTURE TAB

USING Z.
LOOP AT FRED.
WRITE: / FRED-F1

FRED-F2.

ENDLOOP.
ENDFORM .

BC170_2.09.13

Roll Area

Storage Allocation

External Subroutines

REPORT Y170D096.
TABLES : KNA1,

T001, T005.

.

.

.

START-OF-SELECTION.

.

.

.

PERFORM

SUB1(Y170D097) . . . .

.

.

.

REPORT Y170D097.
TABLES : KNA1,

T001, T001G.

.

.

.

START-OF-SELECTION

.

.

.

FORM SUB1 . . . .

.

.

.

NEW-PAGE.

.

.

.

ENDFORM

PERFORM <

name

>(<prog name>) USING . . .

KNA1

T001

T005

T001G

Y170D108

Y170D109

BC170_2.09.14

Function Modules

Function

Builder

FM_01 ...
FM_02 ...

FM Group : FIBU

Program 1

CALL

FUNCTION

‘FM_0’

. . .

Program 3

CALL FUNCTION

‘FM_02’

. . .

FM_03 ...
FM_04 ...

FM Group : XYZ

Program 2

CALL

FUNCTION

‘FM_02’

. . .

BC170_2.09.15

Function Module Parts

FM_01 ...
FM_02 ...

FM Group :

FM Group :

FIBU

FIBU

FM_03 ...
FM_04 ...

FM Group :

FM Group :

XYZ

XYZ

Section I … Attributes

Section II … Interface

Chapter 1 … Import
Chapter 2 … Changing
Chapter 3 … Export
Chapter 4 … Tables
Chapter 5 … Exceptions

Section III … Documentation

Section IV … Source Code

Section V … Global Data

Section VI … Main Program

FM -02

BC170_2.09.16

Creating a Function Group

BC170_2.09.17

Attributes

BC170_2.09.18

Interfaces

Program XYZ.

Call function
‘Y_DEMO_FUNC’

Function Module

Y_DEMO_FUNC

Import

Changing

Export

Tables

Exceptions

BC170_2.09.19

Import/Export Parameter

Interface

Parameter name Default value

Pass parameter

by value

Flag parameter

as optional

‘Ref. Field’

LIFNR LIKE LFA1-LIFNR

‘TYPE’

BC170_2.09.20

Table Parameters/Exceptions

Interface & Documentation

Parameter name

‘LIKE’

Flag parameter

as optional

‘TYPE’

BC170_2.09.21

function y_demo_function_module.

--------------------------------------------------------------------------------------------------

Local interface:

IMPORTING

REFERENCE(FIELD1) LIKE KNA1-NAME1

EXPORTING

VALUE(FIELD3) LIKE KNA1-LAND1

TABLES

TAB STRUCTURE KNA1

CHANGING

VALUE(FIELD2) LIKE KNA1-KUNNR

EXCEPTIONS

INVALID_DATA
SYSTEM_ERROR

-------------------------------------------------------------------------------------------------

endfunction.

*”
*”
*”
*”
*”
*”
*”
*”
*”
*”
*”
*”
*”

*”

Function Module Source Code

BC170_2.09.22

Exceptions

. . .

IF...

RAISE INVALID_OPERATOR.

*(Or use) MESSAGE. . . RAISING

* INVALID_OPERATOR.

ENDIF.

Function Module

INVALID_OPERATOR

BC170_2.09.23

case operator.

when

’+’.

result = operand1 + operand2.

when

’

-

’.

result = operand1 - operand2.

when

’

/

’.

if operand2 <> 0.

result = operand1 / operand2.

else.

raise division_by_zero.

endif.

when

’

’

result = operand1 operand2.

when

others.

raise invalid_operator.

endcase.

*

*

Example - Raising Exceptions

BC170_2.09.24

Calling a Function Module

report ymodemo message-id yj.
parameters:

operand1 type i,
operator,
operand2 like operand1.

data:

result type p decimals 2.

call function ’Y_CALCULATOR’

exporting

operand1

= operand1

operator

= operator

operand2

= operand2

importing

result

= result

exceptions

invalid_operator= 1
division_by_zero= 2
others

= 3.

BC170_2.09.25

exceptions

invalid_operator= 1
division_by_zero= 2
others

= 3.

case sy-subrc.
when 1.
message

e001.

when 2.
message

e005.

when 3.
message

e007.

endcase.

Calling a Function Module

(Continued)

BC170_2.09.26

Program Organization

FUNCTION FA.

L<gr>U01

L<gr>U01

FUNCTION FB.

L<gr>U02

L<gr>U02

FUNCTION-POOL <gr>

Message-ID ZZ.

DATA: “Global DATA

L<gr>TOP

L<gr>TOP

L<gr>UXX

INCLUDE L<gr>

U01.

INCLUDE L<gr>

U02.

.
.
.

*System-defined include files

*User-defined include files

INCLUDE L<gr>TOP.

INCLUDE L<gr>UXX

SAPL <gr>

SAPL <gr>

BC170_2.09.27

Subroutine Includes for

Function Groups

FORM SUB1 USING . . . .

.

.

.

ENDFORM.

FORM SUB2 USING . . . .

.

.

.

ENDFORM.

.

.

.

FUNCTION . . .

.

.

.

PERFORM SUB1 USING . . .

.

.

.

ENDFUNCTION.

•

System-defined include files INCLUDE L<gr> TOP.’ Global Data

•

User defined include files INCLUDE L<gr> F01.’ Subroutines

ABAP program L<gr> F01

Call

Main Program

BC170_2.09.28

FORM SUB1 USING...
DATA: . . .
MOVE. . . TO X.
ENDFORM.

Subroutines

L <gr> F01

Global Data / Local Memory in

the Function Group

FUNCTION . . .
DATA: . . .
MOVE X TO . . .
ENDFUNCTION.

Program

Global Data

FUNCTION-POOL <gr>.

DATA: X

TABLES: . . .

L <gr> TOP

BC170_2.09.29

Test Environment

Export Parameters

Import parameters

FM: Y170 DEMO

Does it work?

Tables

BC170_2.09.30

Managing Function Modules

Attributes

BC170_2.09.31

Remote Function Call (RFC)

External program

External program

External Program. . .

RfcOpen (. . .)

RfcCallReceive (. . .)

RfcClose (. . .)

Program

Program

CALL FUNCTION. . .

DESTINATION. . .

EXPORTING. . .

IMPORTING. . .

TABLES. . .

EXCEPTIONS. . .

Function Group

Function Group

FUNCTION-POOL . . . .

Function Module

Function Module

Function Module

Function Module

FUNCTION REMOTE_CALL

. . .

RAISE ERROR.

. . .

ENDFUNCTION.

ABAP

\/4

RFCLid

BC170_2.09.32

Displaying Function Module

BC170_2.09.33

Modularization:

The Include Technique

BC170_2.09.34

Summary

• The participants should be able to:

–

Create Subroutines

–

Describe the various methods for passing
Parameters to Subroutines

–

Create Function Modules

–

Call Function Modules from ABAP
Programs