Module pool programming

Module pool programming

By – SUDHIR KUMAR


1 Introduction

2 Syntax Description

3 Demonstration

4 Exercises

5 HelpMe
2

Purpose

For performing any kind of task in SAP R/3 system, a transaction is used. SAP
provides a standard set of transactions to manipulate data in the system. But
sometimes, the need to create a customer specific transaction arise due to
following reasons :

Standard SAP may not support that task.
A particular transaction needs to be customized to
suit the customer requirements .

A transaction is defined as a sequence of dynpros(sap term for screens) having
input and output fields and corresponding processing logic behind them to
perform particular task.

3

Use

user-friendly user interface.

format and consistency checks for the data entered by the user.

an easy way of correcting wrong entries.

access to data by storing it in the database.

4


1 PrepareMe

2 Syntax description

3 Demonstration

4 Exercises

5 HelpMe
5

Developing Module pool Program

Tools used:

ABAP Editor(SE38) – To maintain main ABAP program. Program contains data declarations
and modules.

Screen Painter(SE51)– used to maintain components of screen.

Menu Painter(SE41) – Used to design GUI.

Maintain Transaction(SE93) – To create transaction code for program.

Object Navigator (Repository Browser)(SE80) - You should always use the object navigator for
online programs because you will be able to see the hierarchy. From this hierarchy list, you will
be able to branch to the Screen Painter, ABAP Editor, Menu Painter, and ABAP Dictionary.

6

Creating a Program

Create a program using transaction SE38. Program name as
Z_MODULE_TRAINING.
Program type should be Module Pool. Save and activate the program.

Use object navigator(SE80) to further develop the object.

7

Program Structure

Module pool program when viewed from SE80 transaction will have structure
as below,

8

Assigning transaction code

Dialog program is executed using transaction code. We can not execute this
like normal report using execute or pressing F8 button.
Transaction is created using SE93 transaction or from object browser by right
clicking on transaction, click on create. Give name and description and select
the radio button Program and screen (dialog transaction)

9

Use of Screen

Screen is a interface between user and SAP.

Using screen user can provide input to program and in turn program will display
result on screen.

Screen is made up of screen elements such as text box, input/output field, check
box, radio button etc.

 One of the strength is that screen elements are combined with the ABAP
dictionary to allow check the consistency of the data that user has entered.

10

Screen Painter

To start the Screen Painter, choose the corresponding pushbutton on the initial
screen of the ABAP Workbench or enter Transaction SE51.

Best practice is to go to transaction SE80, enter program name and you can
perform one of the below,

1. Create new screens.

2. Test an existing screen.

3. Create new components for an existing screen .

Screen is always created for an existing program.

11

Developing Screen

From Object navigator (SE80) we can create the screen as shown,
Click on Screen, right click and select create option.
Now enter screen number.

12

Developing Screen

A screen number must be unique and up to 4 numbers long.

All screen numbers above 9000 are reserved for Sap’s
customers.

The number 1000 is reserved for table screens and report
selection screen.

Usual practice is to have screen numbers starting with 100 then
continue as 200, 300.

Enter screen number and click on create.

13

Developing Screen

Enter description and save.
Check the screen and activate it.

14

Screen Attributes

Short description – Describes screen purpose

Original language – Default logon language

Package – Identifies the package with which screen is saved

Last changed on/by – Date & time screen is last changed

Last generation – Date & time screen is last generated.

15

Screen Attributes

Screen Type –
 Normal – Default setting

Subscreen – To indicate the screen as a subscreen

Modal dialog box – used to display details in a dialog box. Used for data input,
confirmation/error/help messages.

Selection screen – Identifies selection screen. The system sets this attribute
automatically.

Settings
Hold data – On checking this, system can hold entries made on the screen at
runtime. System automatically displays this data if the user calls the particular
screen again.

16

Screen Attributes

Settings

Switch off runtime compress – On setting this option, the screen is not
compressed at runtime. If you hide fields dynamically at runtime, empty lines
may appear on the screen and the processing may take longer time.
Template non executable – If this attribute is set:
· The screen cannot be generated or activated and therefore cannot be
executed.
· The screen is not included in the screen consistency checks during the
extended program check.
This attribute is primarily for internal use by SAP.
Hold scroll position – On setting the attribute, the scroll position is retained
when the user returns to the screen after processing another screen.

Without application tool bar – To suppress the display of the application toolbar
belonging to the current program status.

Other Attributes
Next Screen – Next screen number to be displayed.

17

Screen Attributes

Other Attributes
Cursor position – Identifies the screen element that contains the cursor when a
screen is first displayed. If you leave this field blank, the system uses the first
screen field that can accept input.

Screen group – Specifies a four-character identifier of a group of associated screens.

Line/Columns –
Occupied – Specifies the size of the screen area currently occupied with
screen elements
Maintained – Size of the screen in rows/columns.

Context menu – It will hold a routine name required to set up the context menu in the
program. This routine connects the screen (elements) from the Screen Painter to the
context menu of the program.
Input/output fields , Text fields, Table controls, Subscreens
Global Class CL_CTMENU , methods- LOAD_GUI_STATUS, ADD_FUNCTION,
ADD_MENU etc..

18

Screen Layout Mode

The Screen Painter has a layout editor that you use to design your screen
layout.
It works in two modes:

 Graphical mode – Drag and drop interface is used, similar to a drawing tool.

Alphanumeric mode – Keyboard and menus are used for designing.

Both modes offer the same functions but use different interfaces. Graphical
mode of screen designing is commonly used.

19

Screen Designing

We have learnt about creating a screen.
To start screen design, click on layout button on screen.
Graphical Screen painter will start loading.

20

Components of Layout Editor

Element palette – Used for creating screen elements. These can be drag &
dropped on screen.

Work Area – Screen design is done in this area.

Element bar – screen element attributes appear in this line. You can also
change these attributes in the corresponding field.

21

Screen Components

Screen element properties can be seen in
detail by double clicking on the element.

Properties of an element can be set here,
such as variable length, F4 help,
input/output, mode of display etc.

 Best practice is to define screen elements
by adopting the corresponding field from
the ABAP Dictionary. However, you can also
use field descriptions that you defined in
your program. To do this you must generate
the program first.

22

Screen Elements

Screen elements are,
Each element will have unique name.
Text field
Function code will be assigned for push buttons, tab titles in tab strip
Input/Output field controls, Input/output fields with the "Dropdown box" attribute.

Check box Each element will have its position on screen, visible/definite length, mode
of display etc.
Radio button
Push button
Tab strip
Box
Sub screen area
Table control
Custom control
Status Icon

23

Screen Elements

Push Button –
Can be placed on screen by drag &
drop from Element palette.
To set the properties, double click
on it.
Each screen element should have
unique name.
In addition to that push button will
have text and function code
assigned to it.

24

Screen Elements

Once screen is designed, it should be saved and checked for errors and activated. Screen looks as below,

25

Testing Screen
Screen can tested by executing F8 or click on button

26

Flow Logic

Default flow logic for any screen is generated as shown below,

28

Menu Painter

In all programs GUI consists of a menu bar, a standard toolbar, an application
toolbar and title bar.
A program’s GUI is created in Menu Painter.
To Create a Menu for a screen, in flow logic uncomment MODULE
STATUS_0400. in PBO event

PROCESS BEFORE OUTPUT.
MODULE STATUS_0400.
PROCESS AFTER INPUT.
* MODULE USER_COMMAND_0400.

29

Menu Painter

Now double click on STATUS_0400. A pop up window will appear. Click on Yes.

Module will be created as below,
*&---------------------------------------------------------------------*
*& Module STATUS_0400 OUTPUT
*&---------------------------------------------------------------------*
module STATUS_0400 output.
* SET PF-STATUS 'xxxxxxxx'.
* SET TITLEBAR 'xxx'.
endmodule. " STATUS_0400 OUTPUT

30

Menu Painter

Uncomment the line SET PF-STATUS 'xxxxxxxx'. a nd replace 'xxxxxxxx‘ with name
‘STATUS_400’.

Click on STATUS_400. Click Yes on the pop-up.

31

Menu Painter

Enter description and choose the status type as Normal screen which is
default.

32

Menu Painter

Click on to expand the menu bar, application toolbar and function
keys.
System and Help are default in menu bar

33

Creating Menu bar

To create a user defined menu enter the name of the menu and double click on
it. We can define options for the menu here as below,

34

Creating Application Tool bar

Application tool bar can also be created in same way as menu bar.

35

Assigning function keys

We can assign code to existing function keys. Only keys for which code is
assigned will be active. We can see this when the menu painter is executed.

36

Execution

We can test the menu painter by clicking on F8 key or execute button

Enter a screen number and title if you want to simulate a whole screen. If you
do not enter a screen number, the system simulates the status using an empty
test screen.

37

Execution

Output as below, New Menu is added, Find Item in Application tool bar, Save,
Back & Print button on standard tool bar enabled.

38

More on Flow Logic

Flow logic refers to code behind the screens. It is the code that processes a
screen.

Flow Logic commands are different than ABAP commands
(e.g., IF … ENDIF is not valid in Flow Logic).

Dynamic Processor (DYNPRO) controls the flow logic and prepares data to be
displayed on the screen.

39

More on Flow Logic

Each screen has its own Flow Logic which is divided into four main events:
• PROCESS BEFORE OUTPUT (PBO) - event processed before the screen
is displayed.

• PROCESS AFTER INPUT (PAI) - event processed after the user has
invoked a function code (e.g., clicked on a pushbutton) or pressed the
‘Enter’ key.

• Process on Value Request (POV) - Triggered when the user requests field
help (F1)
Each screen must be generated. If you make a change to any component of a
screen, the screen must be re-generated before execution.

40

Keywords supported

Keywords supported by flow logic events are as below,

Keyword Function

MODULE Calls a dialog module in an ABAP program
FIELD Specifies the point at which the contents of a screen field
should be transported
ON Used in conjunction with FIELD
VALUES Used in conjunction with FIELD
CHAIN Starts a processing chain
ENDCHAIN Ends a processing chain

CALL Calls a sub screen
LOOP Starts processing a screen table
ENDLOOP Stops processing a screen table

41

PBO Event

By default the module created in PBO event will be like
MODULE STATUS_<screen number>
Ex:-MODULE STATUS_0100.

 This module will be processed before the screen is displayed.

By default this module will be commented. To use this uncomment and double
click on it to get the module created.

*&---------------------------------------------------------------------*
*& Module STATUS_0100 OUTPUT
*&---------------------------------------------------------------------*
module STATUS_0100 output.
* SET PF-STATUS ‘XXX'.
* SET TITLEBAR 'xxx'.
endmodule. " STATUS_0100 OUTPUT

42

PBO Event

Menu bar and title bar can be set in this module.

Menu Bar-
To set menu bar uncomment the SET PF_STATUS and give a name to status as ,

SET PF-STATUS 'STATUS100'.

Double click on STATUS100 and click yes to create GUI status.

43

PBO Event

Title Bar
To assign a title uncomment SET TITLEBAR and give a name as,
SET TITLEBAR 'TITLE100'.

Double click on TITLE100 and click yes to create GUI title. Enter title as below
and click on , save and activate.

Once all the modules in the PBO block are processed, the system copies the
content of the fields in the ABAP work area to their corresponding fields in the
screen work area.

44

PAI Event

Default module in PAI event will be
MODULE USER_COMMAND_<screen number>.
Ex:- MODULE USER_COMMAND_0100.

This event is triggered once the user invokes function code or presses Enter
key on the screen.

System variable SY-UCOMM will hold the function code assigned to the screen
elements (push button, radio button, check box etc).

Within the above module code has to written to branch to group of code based
on the function code from SY-UCOMM.

The system copies the contents of the fields in the screen work area to their
corresponding fields in the ABAP work area once user clicks Enter key on
screen or any function code is invoked.

45

PAI Event- Sample Code

*&---------------------------------------------------------------------*
*& Module USER_COMMAND_0100 INPUT
*&---------------------------------------------------------------------*
MODULE user_command_0100 INPUT.
CASE sy-ucomm.
WHEN 'ENT'.

SELECT ebeln ebelp bukrs
INTO CORRESPONDING FIELDS OF TABLE it_po
FROM ekpo
WHERE ebeln = po_no.

WHEN 'BCK'.
LEAVE TO SCREEN 0.
ENDCASE.
ENDMODULE. " USER_COMMAND_0100 INPUT

46

Includes

To have structured way of code it is best practice to have includes.

There should be a TOP include which will have the data declarations.

Include for PBO modules, include for PAI modules.

Include for POV and POH modules if any.

47

Includes

To create include right click on object name, select Include from the Create
menu.

48

Includes

We can gave the include names as Z<Program>_TOP, Z<Program>_PBO,
Z<Program>_PAI. This will help to understand which modules are covered in
each include.

Each include program will insert a include statement in the main program.

49

Message Statement

The “MESSAGE” statement is used to issue user messages.
Syntax is MESSAGE <tnnn> [WITH <var1> <var2> <var3> <var4>].

t – Message type
nnn –Message Number
WITH – This is optional. It is needed if variables are used in a message.
A message can contain up to four variables, indicated with an ampersand (&)
in the message text.

We can code the Message statement in the PAI event.

50

Message Types

S:success

I
I: information

A: abend

X: exit

W: warning

E: error X
The message type determines where the message is displayed and what
action the user can or must take on the current screen.

51

Messages

Success message is displayed at the bottom of the screen.

If you have next screen then the message will be displayed at the bottom of
the next screen.

Information message is displayed in a dialog box in same screen.

After pressing Enter key on dialog box user will be taken to next screen. The
user is not restricted from going on to the next screen.

52

Messages

Abend message is displayed on the current screen in a dialog box.
The user cannot make any changes to the values on the current screen.
After pressing the ‘Enter’ key on the dialog box, transaction will be terminated.

Exit message is identical to the ABEND message except that the transaction is
terminated with a short dump instead of the message in a dialog box.

WARNING message is displayed at the bottom of the current screen.

On pressing the ‘Enter’ key on the current screen, the user will be taken to the
next screen even if no changes were made on the current screen . Thus user is
not restricted from going on to the next screen.

53

Messages

ERROR message is displayed at the bottom of the current screen.

The user must make changes to the values on the current screen.

On pressing the ‘Enter’ key on the current screen, the user will be taken to the
next screen only if the appropriate corrections were made on the current
screen.

If no corrections were made, the error message would be redisplayed at the
bottom of the current screen.

When a warning or error message is triggered the system will stop at current
screen, prompting the user to make corrections. However the input fields on
the screen will be disabled for input.

54

Handling Error messages

There are 2 ways to issue error/warning messages.
− Issue an error or warning message with the Flow Logic
SELECT statement.
− Define valid values for a screen field with the Flow
Logic VALUES statement.

FIELD statement is a Flow Logic command, not an ABAP command.

The purpose of the “FIELD” statement is to keep a single screen field open for
input after an error or warning message is issued.

FIELD statement is used in PAI event.

Syntax is: FIELD <screen field> MODULE <module name>.

55

FIELD with select statement

Screen field can be validated against entry in database table.

To validate Purchase order number in PAI module,
field PO_NO module PO_CHECK.
MODULE USER_COMMAND_0100.

Module PO_CHECK is as below,
module po_check input.
data: lv_ebeln type ekko-ebeln.
select single ebeln into lv_ebeln
from ekko where ebeln = PO_NO.
if sy-subrc ne 0.
message e003(Z6).
endif.
endmodule. " po_check INPUT

56

Error for invalid input

Error for Purchase order when invalid number is entered.

57

FIELD with Values Check

The Flow Logic VALUES statement defines a set of valid values for the screen
field specified in the FIELD statement.

 If the value entered in this field is not in the valid set, an error message will
be issued by the system.
field PO_NO values ('1', '100').

This indicates PO_NO can take input as either 1 or 100. For any other value
system will through error and the field will be open for input.

With VALUES parameter for field, we can get a list of possible values by
clicking on the drop-down arrow of the screen fields or pressing the ‘F4’ key. It
will list the values mentioned.

58

Values option

PO_NO with values 1 and 100.

59

CHAIN Statement

To keep multiple screen fields open for input after an error or warning
message is displayed, you need to use the “CHAIN” and “ENDCHAIN” Flow
Logic commands.
 These statements group the “FIELD” statements and the “MODULE”
statements together.
 The basic syntax of these statements is:
CHAIN.
FIELD: <f1>, <f 2>,...
MODULE <mod1>.
FIELD: <g1>, <g 2>,...
MODULE <mod2>.
...
ENDCHAIN.
If an error or warning message is issued in <module name>, all the screen
fields listed in the “FIELD” statements will be open for input.

60

Cursor Position

By default, the cursor will be positioned in the first field open for input on a
screen.
Cursor position can be changed in two ways –
1. By setting the cursor position in PBO event-
Syntax - SET CURSOR FIELD <field name>
Cursor will be placed on the screen field mentioned.

2. Cursor position in screen attributes-
Mention the field name where cursor to be placed on screen in
cursor position attribute .

61

Screen commands

The LEAVE SCREEN statement ends the current screen and calls the
subsequent screen.

When the system encounters the “SET SCREEN <screen #>” ABAP statement, it
temporarily overrides the “Next Screen” attribute with this <screen #> and the
PAI processing continues. After all PAI modules are executed, the system goes
to the PBO event of
<screen #>.

62

Screen commands

“LEAVE TO SCREEN <screen #>” ABAP statement, terminates the screen’s
PAI event and immediately goes to the PBO of <screen #>.

The “LEAVE TO SCREEN <screen #> statement performs the functionality of
two statements: “SET SCREEN <screen #>“ and “LEAVE SCREEN”.

“CALL SCREEN <screen #>” ABAP statement, temporarily suspends the
current screen’s PAI processing and immediately goes to the PBO event of
<screen #>. When control returns back to the “calling” screen, its PAI
processing will resume.

63

More on PAI modules

All modules listed in the PAI event get executed from top to bottom.

We can control the execution of the modules using additions to MODULE.

Additions are,
 ON INPUT
 ON REQUEST
 AT EXIT-COMMAND
 AT CURSOR-SELECTION

64

ON INPUT

With the “ON INPUT” addition to the “MODULE” statement, a module will be executed
only if the specified field’s value is not equal to the initial value appropriate to its data
type

 Ex- blanks for character fields and zeroes for numeric fields.

The basic syntax for this conditional execution Flow Logic command is:
− FIELD <screen field> MODULE <module> ON INPUT.
− The PAI <module> will be executed only if the value in
<screen field> is not equal to its initial value.
− The “ON INPUT” addition must be used with a “FIELD”
statement because this condition depends on the value of
a particular field.

If you want to conditionally execute a module that is coded within a
“CHAIN … ENDCHAIN”, you must use “ON CHAIN-INPUT”.

65

ON REQUEST

With the “ON REQUEST”, a module will be executed only if a value has been
entered in the specified field since the screen was displayed.

 The basic syntax for this conditional execution Flow Logic command is:

FIELD <screen field> MODULE <module> ON REQUEST.

− The PAI <module> will be executed only if a value was
entered in <screen field> since the screen was
displayed.

− The “ON REQUEST” addition must be used with a
“FIELD” statement because this condition depends on the
value of a particular field.

If you want to conditionally execute a module that is coded within a
“CHAIN … ENDCHAIN”, you must use “ ON CHAIN-REQUEST”.

66

AT EXIT-COMMAND

With the “AT EXIT-COMMAND” addition to the “MODULE” statement, a module
will be executed only if the user invokes a function code with the ‘E’ function
type.

 Function type assigning is explained in slide 73.

The basic syntax for this conditional execution Flow Logic command is:

MODULE <module> AT EXIT-COMMAND.

67

AT EXIT-COMMAND

− The PAI <module> will be executed only if the user
invokes a FUNCTION type ‘E’.

− The “AT EXIT-COMMAND” addition cannot be used
with a
“FIELD” statement.

If the user invokes a type ‘E’ function code, a module with the “AT EXIT-
COMMAND” addition will be executed immediately.

 It will be executed even before the automatic field checks.

68

Assigning Function type

Function type can be
assigned for screen
buttons and for menu
painter keys.

In menu painter, click
on the required key. In
the pop-up window
select function type as
‘E’ from drop down.

69

AT CURSOR-SELECTION

You can specify that a module should only be called if the cursor is positioned
on a particular screen element.

Syntax - MODULE <mod> AT CURSOR-SELECTION .

The module <mod> is called whenever the function code of the user action is
CS with function type S.

The module is called in the sequence in which it occurs in the flow logic.
 It does not bypass the automatic input checks.

70

AT CURSOR-SELECTION

You can also combine this MODULE statement with the FIELD statement:
FIELD <f> MODULE <mod> AT CURSOR-SELECTION.

For more than one field:
CHAIN.
FIELD: <f1>, <f 2>,...
MODULE <mod> AT CURSOR-SELECTION.
ENDCHAIN.

71

Modifying Screen Fields

All fields of the current screen are stored in the system table SCREEN with
their attributes.

The LOOP AT SCREEN statement places this information in the header line of
the system table.

We can modify the attributes of the fields and update the screen table using
MODIFY SCREEN.
Sample code:
loop at screen.
if screen-name = 'GV_MATNR'.
screen-input = 1.
modify screen.
endif.
endloop.

72

Modifying Screen Fields

You can dynamically modify the following attributes of a field:
− ACTIVE
− REQUIRED
− INPUT
− OUTPUT
− INTENSIFIED
− INVISIBLE
− LENGTH
− DISPLAY 3D
− VALUE HELP
A field attribute is turned “on” with a value of 1. It is turned “off” with a value
of 0.
The statements LOOP AT SCREEN ... ENDLOOP define a loop around a
statement block.

73

Logical Unit of Work (LUW)

Screen Screen Screen
1 2 3
SELECT A
UPDATE A DELETE B
SELECT B

Database Database
Database
Transaction Transaction
Transaction
LUW refers to a collection of actions performed at the database level as a complete
unit.
In this ex: LUW is selecting A and B from the database, updating A, and deleting B.
This would be the desired LUW because we would want to rollback all changes if any
of these actions failed.

74

LUW

Changes will be saved (commit work) in database at the end of third screen.

An SAP LUW will end with either the COMMIT WORK or ROLLBACK WORK
statement.

A logical unit consisting of dialog steps, whose changes are written to the
database in a single database LUW is called an SAP LUW.

If an SAP LUW contains database changes, you should either write all of them
or none at all to the database.

Include a database commit when the transaction has ended successfully, and
a database rollback in case the program detects an error.

75

LUW

Since database changes from a database LUW cannot be reversed in a
subsequent database LUW, you must make all of the database changes for the
SAP LUW in a single database LUW.

In our example, we need to perform UPDATE A and DELETE B at the end of

third screen.

76

SAP Locks

R/3 system contain lock mechanism for SAP LUWs called SAP Locks.

Lock object is created in ABAP Dictionary.

A lock object definition contains the database tables and their key fields on the
basis of which you want to set a lock.

System automatically generates two function modules with the names
ENQUEUE_<lock object name> and DEQUEUE_<lock object name> when a lock
is generated.

Locks can be set and released on corresponding database table by calling
these function modules in program.

77

SAP Locks

Consider below example,

When user clicks on change, the program locks the relevant database object by
calling the corresponding ENQUEUE function.

You can release the lock by calling DEQUEUE function when user clicks on
SAVE or when user clicks on BACK button.

78

Table Control

A table control is an area on the screen where the system displays data in a
tabular form. It is processed using a loop.

To create a table control, drag & drop table control from screen elements on
screen painter. Give a name to table control.
Select the table definition and fields clicking on Dictionary/Program fields
object button.
Each table control need to be declared in declaration part of the program as,
CONTROLS <ctrl> TYPE TABLEVIEW USING SCREEN <scr>.
where <ctrl> is the name of the table control on a screen.

79

Table Control

You must code a LOOP statement in both the PBO and PAI events for each table
in your screen.

This is because the LOOP statement causes the screen fields to be copied back
and forth between the ABAP program and the screen field.


For this reason, at least an empty LOOP...ENDLOOP must be there.

80

Table Control

Sample code -

MODULE STATUS_0100.
LOOP AT it_po INTO wa_ekpo WITH CONTROL tab2 CURSOR
tab2-current_line.
ENDLOOP.

field po_no module po_check.
module exit_mod at exit-command.
loop at it_po.
endloop.

81

Tab Strip Controls

Use –
− To give complex applications a uniform structure and
make it easier for users to navigate between their
components.

− To make the structure of the application easier for
users to learn and understand.

82

Tab Strip Control components

Components of tab strip control

Tab Title – Title of the component to which user can navigate. They are push
buttons.

83

Tab Strip Control components

Tab title row - All tab titles will appear in a row.

Tab Page - A tab page contains a collection of fields that logically belong
together. Tab pages are implemented using subscreens.

Tab Environment - The screen environment around the tabstrip must remain
constant. When you change between tab pages, the menus, application
toolbar, and other fields outside the tabstrip control must not change.

For designing and using tab strip controls, see Transaction BIBS .

84

Step loops

Step loops are considerable less flexible than table controls.

Used to group screen elements together. A step loop is a repeated series of
loop blocks. A loop block consists of one or more loop lines of graphical
screen elements.

Loop blocs can be defined as fixed or variable.
− In a fixed loop, the lower limit of the loop area
always remains as originally defined.
− For a variable loop, the number of repetitions is
adjusted dynamically in the screen program to suit
the size of the current window.

85

Creating a Step loop

Open a screen in the layout editor.

In one or more lines, create the elements you want to repeat.

Select all the elements on the desired line(s) as a group.

Choose Edit Grouping  Step loop Define.

Your element lines now make up a single step loop block. The block includes the
original elements with their attributes and a predefined number of repetition
blocks.

Each repetition contains a copy of the first block without attributes.

 The repetition blocks are consecutively numbered, so that you can establish a
reference to a particular line.

86

Step loops

To use a Step-Loop block in an online program, you must create one work area for
the Step-Loop block. To hold all the lines of a Step-Loop block in the program’s
memory area, use an internal table.

Ex:-TYPES: BEGIN OF TY_REC,
MATNR TTPE MARA-MATNR,
MATKL TYPE MARA-MATKL,
END OF TY_REC.
DATA: GT_MARA TYPE TABLE OF TY_REC WITH
HEADER LINE.

For Step loop the flow logic statement loop must be coded in both PBO and PAI
event. One form of the Flow Logic “LOOP” statement is;
LOOP.
. . . <flow logic statements> . . .
ENDLOOP.

87

Subscreen

A subscreen is a screen that is displayed in a specified area of the main
screen.

 A subscreen cannot be displayed by itself.

The subscreen displayed in the predefined area will depend on the user’s
request on the main screen.

Subscreen is used to vary the fields displayed on a screen. As an example:

− The “main” screen contains the customer number,
name, and a predefined area for a subscreen.
− One subscreen contains customer address
information.
− Another subscreen contains customer bank
information .

88

Creating Subscreen

In main screen,
− In the screen layout, place the screen element
‘subscreen’ on layout.
− You can set the length and width of the subscreen by
double clicking on subscreen.
− Provide unique name to subscreen, save and activate
it.

Subscreen

89

Creating Subscreen

 Create a subscreen
− Create a screen as given in earlier slides.
− Screen type should be subscreen.

− Specify the screen length and height as in main
screen.

− Save the subscreen and go to screen layout. Here
subscreen are will be displayed.

90

Creating Subscreen

User can design in the subscreen area as below,

91

Call subscreen in PBO

To include a subscreen in a predefined area on the “main” screen, use the “CALL
SUBSCREEN” statement in the “main” screen’s PBO event.

syntax : CALL SUBSCREEN <area> INCLUDING <program> <subscreen #>.

− <area> : name of the subscreen area defined on the
“main” screen. This subscreen area will be the
location of the subscreen. This <area> cannot be
enclosed in single quotes.
− <program> : name of the program where the
subscreen exists.

92

Call subscreen in PBO

− <subscreen #> : number of the subscreen to display in
the subscreen area.
− The <program> and <subscreen #> can be literals (i.e.
enclosed in single quotes) or variables.

When the “CALL SUBSCREEN” statement is encountered in the “main” screen’s
PBO event, the system executes the PBO event of the subscreen. Then, the
system returns to finish the PBO event of the “main” screen .

93

Call subscreen in PAI

If the subscreen contains any PAI code, use the “CALL SUBSCREEN”
statement in the PAI event of the “main” screen.

Syntax : CALL SUBSCREEN <area>.

− The <area> is the name of the subscreen area
defined on the “main” screen. This <area> cannot be
enclosed in single quotes.

The “CALL SUBSCREEN” statement must be used to invoke the PAI event of
the subscreen.
- When the “CALL SUBSCREEN” statement is
encountered in the “main” screen’s PAI event, the system
executes the PAI event of the subscreen.

94

Call subscreen in PAI

− Then, the system returns to finish the PAI event of
the “main” screen.

− Without this “CALL SUBSCREEN” statement in the
PAI event of the “main” screen, the PAI event of the
subscreen cannot be processed by the system.
If the subscreen does not contain any PAI code, this “CALL SUBSCREEN”
statement is not needed in the PAI event of the “main” screen.

In both the PBO and PAI of the “main” screen, the “CALL SUBSCREEN”
statement cannot be used inside a “LOOP” or a “CHAIN”.

95

Main screen Flow logic

Main screen flow logic for calling subscreen.

MODULE STATUS_0100.
call subscreen SUB1 including 'Z_MODULE_TRAINING' '0110'.


call subscreen SUB1.

96

Subscreen Restrictions

The following ABAP/4 statements cannot be used in a subscreen’s PBO or PAI
modules (instead, they must be used in the “main” screen):

− SET PF-STATUS
− SET TITLEBAR
− SET SCREEN
− LEAVE TO SCREEN
− CALL SCREEN

− Note: These ABAP/4 statements in a subscreen will
pass a syntax check; however, they will result in
runtime errors.

97

Additions with ABAP OOPS

Enjoy SAP controls (ALV Grid , ALV Tree, HTML controls etc) can be displayed
in screen.

To place these grids we need to have screen element Custom Control placed on
the screen.

Also we need to have ABAP OOPS knowledge. ( Refer package SLIS for
examples)

98

Process on Help

This event is a user programmed help.

If the user presses the ‘F1’ key with the cursor is positioned in <screen field>,
the <supplemental documentation> will be displayed along with the data
element’s short text and documentation.

The only other Flow Logic statement that can be used in the POH event is:

FIELD <screen field> MODULE <module>.

99

Process on Value

This event is a user-programmed help that occurs when the user presses F4 with
the cursor positioned on a screen field.

The modules specified in the subsequent FIELD statement is called instead of
the SAP help.

Syntax is:
FIELD <screen field> MODULE <module>.

100


1 PrepareMe


3 Demonstration

4 Exercises

5 HelpMe
101

Demonstration

Please refer the attached document for demo example.

Microsoft Word
Document

102


1 Introduction


3 Demonstration

4 Exercises

5 HelpMe
103

Exercises

Please refer the attached documents for hands-on.
Exercise 1 – This covers input/output, radio button, table control, screen
navigation, flow logic events, Menu painter.

Microsoft Word
Exercise 2 – This covers tab Document
strip, subscreen, table control, 4 flow logic
events, screen navigation, menu painter.

Microsoft Word
Document

104


1 Introduction


3 Demonstration

4 Exercises

5 HelpMe
105

HelpMe

Refer help.sap.com

Refer Transaction code ABAPDOCU (check in drop down ABAP User Dialogs) for
documentation and examples

For screen elements and controls (table control, tabstrip) refer transaction BIBS.

Refer package SLIS for examples of ALV grids, ALV Tree.

106

Module pool programming

Recommended

More Related Content

What's hot (20)

Viewers also liked (18)

Similar to Module pool programming (20)

Module pool programming

Editor's Notes