Sunday, September 1, 2024

ABAP FAQ - Module Pool

 

Module Pool

 

Transactions:

A transaction is a program that conducts a dialog with the user.  In a typical dialog, the system displays a screen on which the user can enter or request information. Based on the the user input or request, the program executes the appropriate actions like,  it branches to the next screen, displays an output, or changes the database.

 

Explain what is a transaction in SAP terminology.

-     In SAP terminology, a transaction is series of logically connected dialog steps.

 

Explain how SAP GUI handles output screen for the user.

-         User terminal input is accepted by SAP GUI and sent to the SAP dispatcher. The dispatcher co-ordinates the information exchange between the SAP GUIs and the work processes. The dispatcher first places the processing request in request queues, which it then processes. The dispatcher dispatches the requests to the available work process. The actual processing takes place in the work process. When processing is complete, the result of a work process is returned via the dispatcher to the SAP GUI. The SAP GUI interprets the received data and generates the output screen for the user.

 

What is LUW or Database LUW or Database Transaction ?

-       A “LUW” ( logical unit of work ) is the span of time during which any database updates must be performed .  Either they are all performed  ( committed ) , or they are all thrown away ( rolled  back ). 

 

 LUW ( or “database LUW” or  “database transaction” )

This is the set of updates terminated by a database commit.  A LUW lasts, at most, from one screen change to the next ( because the SAP system triggers database commits automatically at every screen change ).

 

LUWs help to guarantee database integrity. When an LUW has been successfully concluded, the database is once again in a correct state. If, however, an error occurs within an LUW, all database changes made since the beginning of the LUW are canceled and the database is then in the same state as before the LUW started.

 

An LUW begins

 

-       Each time you start a transaction

-       When the database changes of the previous LUW have been confirmed (database commit) or

-       when the database changes of the previous LUW have been cancelled (database rollback)

 

An LUW ends

 

-       When the database changes have been confirmed (database commit) or

-       When the database changes have been canceled (database rollback)

 

What is SAP LUW or Update Transaction ?

-     Update transaction ( or “SAP LUW”)

This is a set of updates terminated by an ABAP/4 commit. A SAP LUW may last much longer than a database LUW, since most update processing extends over multiple transaction screens.The programmer terminates an update transaction by issuing a COMMIT WORK statement.

 

Does the external program run in the same SAP LUW as the caller, or in a separate one?

-     Transactions run with a separate SAP LUW

-     Reports run with a separate SAP LUW

-     Dialog modules run in the same SAP LUW as the caller

-       Function modules run in the same SAP LUW as the caller

The only exceptions to the above rules are function modules called with IN UPDATE TASK (V2 function only) or IN BACKGROUND TASK (ALE applications). These always run in their own (separate) update transactions.

 

 

What are the requirements a dialog program must fulfill ?

-       A dialog program must fulfill the following requirements

.           a user friendly user interface

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

.           easy correction of input errors

.           access to data by storing it in the database.

 

What are the basic components of dialog program ?

-       Screens (Dynpros)

Each dialog in an SAP system is controlled by dynpros. A Dynpro consists of a screen and its flow logic and controls exactly one dialog step.

-       ABAP/4 module pool

Each dynpro refers to exactly one ABAP/4 dialog program. Such a dialog program is also called a module pool, since it consists of interactive modules.

 

What is a dynpro ? What are its components ?

-       A dynpro (DYnamic PROgram) consists of a screen and its flow logic and controls exactly

one dialog step.

      -     The different components of the dynpro are:

            Flow logic: Calls of the ABAP/4 modules for a screen

Screen layout: Positions of the texts, fields, pushbuttons, and so on for a screen

            Screen attributes: Number of the screen, number of the subsequent screen, and others

            Field attributes: Definition of the attributes of the individual fields on a screen

 

 

What is screen flow logic? What are the selections in it? Explain PAI and PBO?

 

Ans - Screen flow logic contains the procedural part of a screen. The screen flow logic is like an ABAP program in that it serves as a container for processing blocks. There are four event blocks, each of which is introduced with the screen keyword PROCESS:

 

PROCESS BEFORE OUTPUT.
...

PROCESS AFTER INPUT.
...

PROCESS ON HELP-REQUEST.
...

PROCESS ON VALUE-REQUEST.

Selections are performed in PAI.

 

PROCESS BEFORE OUTPUT (PBO) is automatically triggered after the PAI processing of the previous screen and before the current screen is displayed. You can program the PBO processing of the screen in this block. At the end of the PBO processing, the screen is displayed.

 

PROCESS AFTER INPUT (PAI) is triggered when the user chooses a function on the screen. You can program the PAI processing of the screen in this block. At the end of the PAI.

processing, the system either calls the next screen or carries on processing at the point from which the screen was called.

 

PROCESS ON HELP-REQUEST (POH) and PROCESS ON VALUE-REQUEST (POV) are triggered when the user requests field help (F1) or possible values help (F4) respectively. You can program the appropriate coding in the corresponding event blocks. At the end of processing, the system carries on processing the current screen.

 

Can we use WRITE statement in screen fields ? If not how is data transferred from field data to screen fields

-       We cannot write field data to the screen using the WRITE statement.  The system instead transfers data by comparing screen field names with ABAP/4 variable names. If both names are the same, it transfers screen field values to ABAP/4 program fields and vice-versa.   This happens immediately before and immediately after displaying the screen.

 

How does the interaction between the Dynpro and the ABAP/4 modules takes place ?

-       A transaction is a collection of screens and ABAP/4 routines, controlled and executed by a Dialog processor.  The Dialog processor processes screen after screen, thereby triggering the appropriate ABAP/4 processing for each screen.  For each screen, the system executes the flow logic that contains the corresponding ABAP/4 processing.  The control passes from screen flow logic to ABAP/4 code and back.

 

How does the Dialog handle user requests ?

-     When an action is performed, the system triggers the PROCESS AFTER INPUT event. The data passed includes field screen data entered by the user and a function code. A function code is a technical name that has been allocated in the Screen Painter or Menu Painter to a menu entry, a pushbutton, the ENTER key or a function key of a screen. An internal work field (ok-code) in the PAI module evaluates the function code, and the appropriate

      action is taken.

 

How are the function codes handled in flow logic ?

-     When the user selects a function in a transaction, the system copies the function code into a specially designated work field called OK_CODE. This field is global in the ABAP/4 module pool.  The OK_CODE can then be evaluated in the corresponding PAI module.

The function code is always passed in exactly the same way, regardless of whether it comes from a screen's pushbutton, a menu option, function key or other GUI element.

 

What controls the screen flow ?

-       The SET SCREEN and LEAVE SCREEN statements control screen flow.

 

 

 

 

 

 

What are “field” and “chain” statements ?

-       The FIELD and CHAIN flow logic statements let you program your own field checks. FIELD and CHAIN tell the system which fields you are checking,and whether the system should perform checks in the flow logic or call an ABAP/4 module.

 

What is an on “*-input field” statement ?

-       ON *-INPUT

The ABAP/4 module is called if the user has entered a "*" in the first character of the field, and the field has the attribute *-entry in the Screen Painter. You can use this option in exceptional cases where you want to check only fields with certain kinds of input.

 

What are conditional chain statements ?

-       ON CHAIN-INPUT similar to ON INPUT.

The ABAP/4 module is called if any one of the fields in the chain contains a value other than its initial value (blanks or nulls).

           ON CHAIN-REQUEST

This condition functions just like ON REQUEST, but the ABAP/4 module is called if any one of the fields in the chain changes value.

 

What is “at exit-command” ?

-       The flow logic keyword AT EXIT-COMMAND is a special addition to the MODULE statement in the flow logic. AT EXIT-COMMAND lets you call a module before the system executes the automatic field checks.

 

Which function type has to be used for using “at exit-command” ?

-       To use AT EXIT-COMMAND, we must assign a function type ‘E’ to the relevant function in the Menu Painter or Screen Painter.

 

What is the difference between SET SCREEN and CALL SCREEN ?

With SET SCREEN, the current screen simply specifies the next screen in the chain. control branches to this next screen as soon as the current screen has been processed. Return from next screen to current screen is not automatic. It does not                                                                                                                                                                                                                                                                                                                                                                                                                               interrupt processing of the current screen.  If we want to branch to the next screen without finishing the current one, use LEAVE SCREEN.

 

With CALL SCREEN, the current (calling) chain is suspended, and a next screen (or screen chain) is called in. The called screen can then return to the suspended chain with the statement LEAVE   SCREEN TO SCREEN 0. Sometimes we might want to let an user call a popup screen from the main application screen to let them enter secondary information. After they have completed their entries, the users should be able to close the popup and return directly to the place where they left off in the main screen. Here comes CALL SCREEN into picture. This statement lets us insert such a sequence into the current one.

 

Can we specify the next-screen number with a variable.  ( Yes /  No ).

Yes.

 

 

The field SY-DYNNR refers to ________________.

Number of the current screen.    

 

 

 

What is a dialog module ?

A dialog module is a callable sequence of screens that does not belong to a particular transaction. Dialog modules have their own module pools, and can be called by any transaction.

 

The syntax used to call a screen as a dialog box  ( popup ) is _________________.

CALL SCREEN <screen number>

STARTING AT <start column> <start line>

ENDING AT   <end column>   <end line> .

 

What is a “call mode” ?

In the ABAP/4 world, each stackable sequence of screens is a "call mode". This is important because of the way you return from a given current sequence. To terminate a call mode and return to a suspended chain, set the "next screen" to 0 and leave to it:

LEAVE TO SCREEN 0 or ( SET SCREEN 0 and LEAVE SCREEN ).  When you return to the suspended chain, execution resumes with the statement directly following the original CALL SCREEN statement.  The original sequence of screens in a transaction is itself is a

calling mode.  If you LEAVE TO SCREEN 0 in this sequence ( that is, without having stacked any additional call modes ), you return from the transaction altogether.

 

The maximum number of calling modes stacked at one time is ______.

Nine.

 

What is LUW or Database LUW or Database Transaction ?

A “LUW” ( logical unit of work ) is the span of time during which any database updates must be performed in an “all or nothing” manner.  Either they are all performed  ( committed ) , or they are all thrown away ( rolled  back ).  In the ABAP/4 world, LUWs and transactions can have several meanings:

LUW ( or “database LUW” or  “database transaction” )

This is the set of updates terminated by a database commit.  A LUW lasts, at most, from one screen change to the next ( because the SAP system triggers database commits automatically at every screen change ).

 

What is SAP LUW or Update Transaction ?

Update transaction ( or “SAP LUW”)

This is a set of updates terminated by an ABAP/4 commit. A SAP LUW may last much longer than a database LUW, since most update processing extends over multiple transaction screens.The programmer terminates an update transaction by issuing a COMMIT WORK statement.

 

What happens if only one of the commands SET SCREEN and LEAVE SCREEN is used without using the other?

If  we use SET SCREEN without LEAVE SCREEN, the program finishes processing for the current screen before branching to <scr no>.  If we use LEAVE SCREEN without a SET SCREEN before it, the current screen process will be terminated  and branch directly to the screen specified as the default next-screen in the screen attributes.

 

 

What is significance of the screen number ‘0’ ?

In "calling mode", the special screen number 0 (LEAVE TO SCREEN 0) causes the system to jump back to the previous call level.  That is, if you have called a screen sequence with CALL SCREEN leaving to screen 0 terminates the sequence and returns to the calling screen.  If you have not  called a screen sequence, LEAVE TO SCREEN 0 terminates the transaction.

 

What does the command ‘SUPPRESS DIALOG’ do ?

Suppressing of entire screens is possible with this command.  This command allows us to perform screen processing “in the background”. Suppresing screens is useful when we are branching to list-mode from a transaction dialog step.

 

What is the significance of the memory table ‘SCREEN’ ?

At runtime, attributes for each screen field are stored in the memory table called ‘SCREEN’.  We need not declare this table in our program.  The system maintains the table for us internally and updates it with every screen change.

 

What are the fields in the memory table ‘SCREEN’ ?

-     Name              Length             Description

 

Why grouping of fields is required ? What is the maximum number of modification groups for each field ?

-     If the same attributes need to be changed for several fields at the same time these fields can be grouped together.  We can specify up to four modification groups for each field.

 

 

What is a screen group ? How it is useful ?

Screen group is a field in the Screen Attributes of a screen.  Here we can define a string of up to four characters which is available at the screen runtime in the SY-DNGR field.  Rather than maintaining field selection separately for each screen of a program, we can combine logically associated screens together in a screen group.

 

What is a Subscreen ? How can we use a Subscreen ?

A subscreen is an independent screen that is displayed in an area of another ("main") screen. To use a subscreen we must call it in the flow logic ( both PBO and PAI ) of the main screen.   The CALL SUBSCREEN statement tells the system to execute the PBO and PAI events for the subscreen as part of the PBO or PAI events of the main screen. The flow logic of your main program should look as follows:

PROCESS BEFORE OUPTPUT.

CALL SUBSCREEN <area> INCLUDING '<program>' '<screen>'.

PROCESS AFTER INPUT.

CALL SUBSCREEN <area>.

Area is the name of the subscreen area you defined in your main screen. This name can have up to ten   characters. Program is the name of the program to which the subscreen belongs and screen is the  subscreen's number.

 

What are the restrictions on Subscreens ?

Subscreens have several restrictions.  They cannot:

Set their own GUI status

Have a named OK code

Call another screen

Contain an AT EXIT-COMMAND module

Support positioning of the cursor

 

How can we use / display table data in a screen ?

ABAP/4 offers two mechanisms for displaying and using table data in a screen. These mechanisms are TABLE CONTROLS and STEP LOOPS.

 

 

What are the differences between TABLE CONTROLS and STEP LOOPS ?

-     TABLE CONTROLS are simply enhanced STEP LOOPS that display data with the look and feel of a table widget in a desktop application.  But from a programming standpoint, TABLE CONTROLS and STEP LOOPS are almost exactly the same.  One major difference between STEP LOOPS and TABLE CONTROLS is in STEP LOOPS their table rows can span more than one line on the screen.  By contrast the rows in a TABLE CONTROLS are always single lines, but can be very long.  ( Table control rows are scrollable ).  The structure of table controls is different from step loops.  A step loop, as a screen object, is simply a series of field rows that appear as a repeating block.  A table control, as a screen object consists of :   i )  table fields ( displayed in the screen )    ii )  a control structure that governs the table display and what the user can do with it.

 

 

Why do we need to code a LOOP statement in both the PBO and PAI events for each table in the screen ?

We need to code a LOOP statement in both PBO and PAI events for each table in the screen.  This is because the LOOP statement causes the screen fields to be copied back and forth between the ABAP/4 program and the screen field.  For this reason, at least an empty LOOP......ENDLOOP must be there.

 

The field SY-STEPL refers to ___________________ .

The index of the screen table row that is currently being processed. The system variable SY-STEPL only has a meaning within the confines of LOOP...ENDLOOP processing. Outside the loop, it has no valid value.

 

How can we declare a table control in the ABAP/4 program ?

Using the syntax  controls <table control name> type tableview using screen <scr no>.

 

Differentiate between static and dynamic step loops. 

Step loops fall into two classes:  Static and dynamic.  Static step loops have a fixed size that cannot be changed at runtime.  Dynamic step loops are variable in size.  If the user re-sizes the window the system automatically increases or decreases the number of step loops blocks displayed.  In any given screen you can define any number of static step loops but only a single dynamic one.

 

What are the two ways of producing a list within a transaction ?

By submitting a separate report.

By using leave to list-processing.

 

What is the use of the statement Leave to list-processing ?

Leave to list-processing statement is used to produce a list from a module pool.  Leave to list-processing statement allows to switch from dialog-mode to list-mode within a dialog program.

 

When will the current screen processing terminates ?

A current screen processing terminates when control reaches either a Leave-screen or the end of PAI.

 

How is the command Suppress-Dialog useful ?

Suppressing entire screens is possible using this command.  This command allows

us to perform screen processing “in the background”.  The system carries out all PBO and PAI logic, but does not display the screen to the user.  Suppressing screens is useful when we are branching to list-mode from a transaction dialog step.

 

What happens if we use Leave to list-processing without using Suppress-Dialog ?

If we don't use Supress-Dialog the next screen will be displayed but as empty.

when the user presses ENTER, the standard list output is displayed.

 

How the transactions that are programmed by the user can be protected ?

By implementing an authority check.

 

What are the modes in which any update tasks work ?

Synchronous and Asynchronous.

 

What is the difference between Synchronous and Asynchronous updates ?

A program asks the system to perform a certain task, and then either waits or doesn't wait for the task to finish. In synchronous processing, the program waits: control returns to the program only when the task has been completed. In asynchronous processing, the program does not wait: the system returns control after merely logging the request for execution.

 

What is the difference between Leave Transaction and Call Transaction ?

-     In contrast to LEAVE TO TRANSACTION, the CALL TRANSACTION statement causes the system to start a new SAP LUW . This second SAP LUW runs parallel to the SAP LUW for the calling transaction.

 

 

Overall how do you write transaction program in SAP?

Create the transaction using object browser (SE80)

Define the objects e.g. screen, Transactions. – Modules – PBO, PAI.

And you can create a transaction from SE93 also.

 

Does SAP has a GUI screen painter? If yes What operating systems is it available on? What is the other type of screen painter called?

Yes

On what OS is it available – Window based.

Other type of screen painter – alpha numeric screen painter.

 

What are step loops? How do you program page down page up in step loop?

Step loops: Method of displaying a set of records.

Page down  & Page up: decrement / increment base counter

Index = base + sy-step1 – 1

 

Normally how many and what files get created when a transaction program is written? What is top XXXXXXTOP program?

Main program with A Includes

I  ) TOP INCLUDE – GLOBAL DATA

II ) Include for PBO

III) Include for PAI

IV) include for Forms

 

 

Where is processing logic located in an on-line program?

Ans :- ABAP/4 program (module pool)

 

Describe the online processor. What is its function?

Ans :- Controls the flow of online program.

 

How are screen names defined? Do you create a screen first or define your program first?

Ans :- Define the program first and then create a screen.

 

What does PBO stands for? When is the PBO logic performed?

Ans :- PROCESS BEFORE OUTPUT –Processed before the screen is displayed.

 

What does PAI stands for? When is the PAI logic performed?

Ans :- PROCESS AFTER INPUT –Processed after the user has pressed ENTER.

 

How is data passed from the screen fields to the ABAP/4 program?
Ans :-  Through the flow logic.

 

What does the TOP Include do for you as a programmer?

Ans: For global declarations.

 

What are the steps in creating screen?

Where are the module statement declared? Where is the logic within each module?
Ans :-

1.            Go to SE41 ( Screen Painter )

Enter the program name and screen number . Press Enter.

2.            Design the screen and save, check and activate it.

 

      Module statements are in the flow logic within each module is in the ABAP/4  module pool

Program.

 

What is the significance of  the word ‘OUTPUT’ in the declaration

MODULE TEST_KNOWLEDGE OUTPUT

 

ENDMODULE.

Ans :- Then we know that it is part of the PBO, therefore is processed before the screen is presented.

 

Describe the fields on the screen ?

Ans :-  Attributes screen , Screen types ,follow up screens , cursor position etc. After you have entered the screen number, the screen branches to the screen attribute maintenance. Enter a short description , select the type NORMAL and specify the number of the follow-up screen.

 

What are the three components of ON-LINE program?

Ans :- Screen , ABAP/4 program and transaction code.

 

What is gained by using the Dictionary Fields menu option when creating your screen?

Ans :- The fields you have created inherits the same attributes as those in the Data Dictionary.

 

How to Create a  checkbox , frame, pushbuttons and radio buttons on a screen?

Ans :- Just type a name and go to graphic element push button.

 

How do you assign an OK_CODE for a push button? How it is used in your ABAP?

Ans :- In the field list ,name the element and give it the value that it will represent when pushed       You must make sure that you clear the field that represents the pushbutton after every check.

What automatic checks does the screen perform? (should be four)

 

Describe all four and how they are used?

Ans :- The field format, required input, a foreign key table ,parameters.

 

What are the two methods to declare input field as mandatory?

If you set required field as program attribute, the user must enter a value in the field. Required fields appear on the screen containing a question mark (?).

 

How does foreign key work? What you have to put in your screen to identify the foreign key?

No? Then where is the foreign key identified?

Ans :- You have defined a screen field by referring to a Data Dictionary, which has a check table. When the foreign key is checked the system compares the values of the fields to be checked with the contents of the key fields of the corresponding table.

 

What are the two effects of the foreign key from a user standpoint?

Ans :- Possible entries & a check against the key field contents.

 

What is user defined validation checks in the flow logic?

Ans :- FIELD…SELECT FIELD…VALUES or in the module pool FIELD…MODULE.

 

Does the value command in the flow logic go in the PAI or the PBO event?

Ans :- PAI.

 

If an error occurs in the module pool, which fields are available for entry and which are display only fields?

Ans :- Only those fields defined with the FIELD statement before MODULE & relevant checks in a chain.

 

When is the chain command used in the PBO event?

Ans :- If you want to make more than one field ready for input after an error.

 

What table stores the online messages? What is the message class and what is its significance?

Ans :-  Table T100. The message class is a specific class of messages for a group of transactions.

 

What are the 5 different message types and how are they handled by the system? What is then difference between the Warning and Error messages?

Ans :-

A : Abend   Message displayed on the current screen and subsequent task terminated

I : Information  Message displayed on the current screen , but user can continue program by pressing ENTER

E: Error Message displayed on the current screen. With FIELD statements , the fields concerned become ready again for input and user is required to make the entry /entries again

W : Warning  As E message , but correcting input is optional

S: Success Message displayed on the follow-up screen as an I message.

 

What does WITH statement add to a message?

Ans :- In the place of the & or $ the fields or values are placed in the error message.

 

What effect does the FIELD statement have within the flow logic?

Ans :- The field statement resets the fields so those fields are ready for input again.

 

Where are the messages displayed on the screen?

Ans :- At the bottom.

 

Is the SET PARAMETER statement to be issued in PBO or PAI module? Why?

Ans :- PAI, the value must be input into the fields first before it can be placed in the buffer.

 

Where does the GET PARAMETER statement get its values? Which field gets populated with the new value?

Ans :- From the buffer.

 

Where can the SET CURSOR command be executed? What is its effect?      

Ans :- In PBO, To position the CURSOR in a particular field after the screen is displayed.

 

What are the matchcodes and how do they affect the screen field? Where are they specified in the online program?

Ans  :-  In the Properties window of the Field.

 

What is the effect of an ON CHAIN-REQUEST command in your flow logic?

Ans :-  When value of any of the fields between CHAIN…..ENDCHAIN is attempted to change.

 

What commands are used to change database table entries?

Ans :- 

 

How can you check if the changes to the database were successful?

Ans :-

 

What is the difference between the Long form and the short form of making database changes?

Ans :-  Long Form:

                        Update MARA and set brgew =  0 where matnr = ‘MAT!’.

                        This is a standard Oracle Statement to modify the entry in the Database.

            Short Form:

            MARA-MATNR = ‘MAT1’. MARA-BRGEW = 0.

                              Modify MARA.

                              This is an SAP defined statement to modify the table.

                              It is more secure and consistent.

 

What is the advantages using the SAP long form over the short form of database changes?

Ans :-  May be Fast Effect.

 

Can ‘where’ clause be used when updating database entries?

Ans :-  Yes.

 

Describe array operations and their advantages?

Ans :-

 

What is logical unit of work? How is it defined?

Ans :-  Logical Unit of work is a block of memory area where database contents are stored and manipulated.

For every SAP application LUW is automatically created for database communication. Besides this we have SAP LUW s also there.

 

What function is performed by the commit work command?

Ans :- When you perform Commit , all the LUW s work will be reflected to the database.

 

Why is it so important for a programmer to check the lock entries?

Ans :- To find out if record is locked and also to maintain data integrity.

 

How can you find a lock entry for a database table?

Ans :- The function module ‘ENQUEUE <lock object>’ checks whether a lock was triggered for the same object. Otherwise an exception FOREIGN_LOCK is carried out. If the object is not locked the function module sets the lock.

 

What steps are necessary to set a lock on a record within a database table?

Ans :-

Execute CALL FUNCTION statement

CALL FUNCTION “ENQUEUE <lock object’>

EXPORTING…

EXCEPTIONS…

CASE SY-SUBRC.

.

.

ENDCASE.     

 

How do you unlock the entry? Why is this necessary?

Ans :-

Execute the CALL FUNCTION statement

CALL FUNCTION ‘DEQUEUE <lock object>’

EXPORTING…

It is important to unlock the entry so others can update it.

What is the difference between  ‘CALL SCREEN # # # ‘ and ‘SET SCREEN ### ’

   LEAVE SCREEN?

Ans :-      

SET SCRREN statement sets or overwrites the follow-up screen.

LEAVE SCREEN executes the screen number currently in the follow-screen field

CALL SCREEN interrupts the processing of the current screen to call a new screen or a chain of screens, processing of the current screen is resumed directly after the call.      

 

After a CALL SCREEN command where does the processing return after the screen has been executed?

Ans :- It returns the processing to the calling screen.

 

Which is the more similar to a call with return, the SET SCREEN or the CALL SCREEN?

Ans :- The CALL SCREEN command.

 

What function is performed by the SET SCREEN 0 command?

Ans :- Returns to the original screen.

 

What are the main differences between the repot status and screen status?

Ans :-

 

Where must you place the SET PF-STATUS command in your online program?

Ans :- Place it in the PBO module of the screen.

 

Why is it good idea to clear OK_CODE field after deciding which action to take?

Ans :- You need to clear the OK code to avoid sending a screen that already has a function code.

 

How do you specify that a function is an exit type command?

Ans :- By specifying function type E for the pushbuttons or menu options in the screen painter or menu painter.

What is the purpose of the ‘AT EXIT-COMMAND’?

Ans :- Usually there are many ways to leave a screen (back,exit,cancel) .This command will perform termination logic for all functions of type E.

 

What are screen groups?

Ans :- A group of screen fields such as radio buttons or checkboxes.

 

What is the correct syntax for dynamically modifying a large number of screen fields?

Ans :-

MODULE MODIFY _SCREEN_OUTPUT

.

.

.

LOOP AT SCREEN

IF SCREEN –GROUP = 3D ‘GR1’

SCREEN-INPUT=3D 1

ENDIF.

IF SCREEN-NAME = 3D ‘TAB-FIELD’

SCREEN-ACTIVE=3D 0.

ENDIF.

MODIFY SCREEN.

ENDLOOP.     

 

What is the name of the internal table that stores the screen information?

Ans :- SCREEN.

 

What is the purpose of the MODIFY command when performing the dynamic screen modifications?

Ans :- after you activate or deactivate the field attributes by assigning them 1 or 0, you save the modifications via MODIFY SCREEN command.

 

Direction for the use of check box and radio buttons in screen painter?

Ans :-

Creating Radio Button and Check Boxes on the screen

Go to the full screen editor.

Place an underscore at the point where you want to place the field.

Define the name of the field using <Field Attributes>

Place the cursor on the field and press <Graphic element>

Then press <Radio Buttons> or <Check boxes> depending on which graphic element you want

Then you group related check boxes and radio boxes.

 

What are user Exits and transactions?

Ans :-  Generally, user exits are the forms defined within SAP standard code (usually starting with user exit). These predefined areas in the code allow programmers to insert custom defined code into the standard processing of a transaction (e.g. allow resorting of the batch sequence in VA01 batch processing). There are many specific examples if you are interested, but usually user exits are searched for when a specific use is being analyzed.

 

What happens if you enter 0 in NEXT Screen attribute?

Ans :- It does not go to any other screen and it moves back one level. However you can control this in run-time using SET SCREEN command.

 

How to modify the attributes of screen fields at run time ?.

We loop through the fields of the screen. When you find the name of a screen field you want to

modify, set attributes for the field and use MODIFY SCREEN to update the

attribtes.

 

You can find the attributes in the internal table SCREEN.

This loop makes some of the screen fields invisible ind a selection screen:

AT SELECTION-SCREEN OUTPUT.                                            

LOOP AT SCREEN.                                                    

IF screen-name = 'P_VERAB' OR                                    

screen-name = 'P_STXT1' OR                                     

screen-name = 'P_STXT2' OR                                    

screen-name = '%_P_VERAB_%_APP_%-TEXT' OR                     

screen-name = '%_P_STXT1_%_APP_%-TEXT' OR                     

screen-name = '%_P_STXT2_%_APP_%-TEXT'.               

 

screen-active = '0'.                                          

MODIFY SCREEN.                                                 

ENDIF.                                                           

ENDLOOP.                                                            

 

How to leave dynpro allthough required entry not made ?

 

In the menu painter - Function attributes for the button,  set Functional

type to E (Exit command)

 

PROCESS AFTER INPUT.

Call module that leaves screen before User_Command_xxxx is executed

 

MODULE ReturnExit AT EXIT-COMMAND. 

MODULE user_command_1000.

 

MODULE returnexit.      

CASE sy-ucomm.       

WHEN 'CANC'.  "Or whatever you want to call it      

Clear w_screen.

LEAVE TO SCREEN 0.

 

ENDCASE.              

ENDMODULE.              

 

Calling a report from a dynpro

 

There are to ways to do this:

Use leave to list-processing if you  want to do it in your module pool. You will not be able to use

selection-screens.

Use the submit statement to start a seperate report from your dynpro.

Anyone who  have idea on how to know the selected value on run-time?

How can get the table control attribute selected value ?   I try to read the value in debuger  which is #

(table_control-cols-selected). There is no difference on   the other row which is not selected.

 

The tc-cols-selected is for column selection only.  For row selection you have two scenarios

 

turn on the SelColumn attribute in screen painter, give it a name and declare an abap variable with the same name type C length 1.  In your PAI loop at itab, when the selected row is processed the abap variable will = 'X'.  At this point you can save the record or key.

 

you can determine which row the cursor is on in your table control as follows:

 

DATA: LINE_SEL LIKE SY-STEPL,

TABIX LIKE SY-TABIX

 

GET CURSOR LINE LINE_SEL.

TABIX = <table control>-TOP_LINE + LINE_SEL - 1.

 

TABIX  is now the index of the selected row.

 

F4 Help - Calling it from a program  and limiting values ?

 

To avoid the standard F4 help to be show, insert the event PROCESS ON-VALUE-REQUEST in the  program and add a field statement for the field that should trigger the F4 help. In the mdoule called from

 

PROCESS ON-VALUE-REQUEST, call function module

F4IF_FIELD_VALUE_REQUEST.

 

Example 1 - Dynpro

 

process before output.

.....

 

 

process after input.

.....

 

 

PROCESS ON VALUE-REQUEST.

FIELD it_zsd00003-prctr MODULE f4_help_for_pctr.

 

MODULE f4_help_for_pctr INPUT.

 

NOTE:

Tabname/fieldname is the name of the table and field

for which F4 should be shown.

*

Dynprog/Dynpnr/Dynprofield are the names of the Progran/Dynpro/Field

in which the f4 value should be returned.

*

Value: The value of the Dynpro fuield when calling the F4 help.

You can limit the values shown, by inseting a value in this parameter

e.g  '50*' to show only values beginning with 50

 

CALL FUNCTION 'F4IF_FIELD_VALUE_REQUEST'

 

EXPORTING

tabname                   = 'ZSD00003'

fieldname                 = 'PRCTR'

*   SEARCHHELP                = ' '

*   SHLPPARAM                 = ' '

dynpprog                  = 'ZSD00002_BRUGERKONV_LISTE'

dynpnr                    = '0100'

dynprofield               = 'IT_ZSD00003-PRCTR'

*   STEPL                     = 0

value                     = '50*'

*   MULTIPLE_CHOICE           = ' '

*   DISPLAY                   = ' '

 

*   SUPPRESS_RECORDLIST       = ' '

*   CALLBACK_PROGRAM          = ' '

*   CALLBACK_FORM             = ' '

TABLES

*   RETURN_TAB                =

EXCEPTIONS

*   FIELD_NOT_FOUND           = 1

*   NO_HELP_FOR_FIELD         = 2

*   INCONSISTENT_HELP         = 3

*   NO_VALUES_FOUND           = 4

*   OTHERS                    = 5

.

IF sy-subrc <> 0.

MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO

WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.

 

ENDIF.

 

 

ENDMODULE.                 " F4_help_for_pctr  INPUT.

 

What you can do with a transaction variant

Insert default values into fields

hange the ready for input status for fields

Hide various screen elements, menu functions or entire screens

Adjust table control settings

Note: Transaction variants can only be used with dialog transactions.

 

How to create a transaction variant

Transaction variants are created with transaction:  SHD0

In the field Transaction on SHD0 enter the transactioncode for the screen you want tpo modify (E.g. VA03) . In the field Variant on SHD0 enter  the name you want to give the transaction variant (E.g. ZVA03)

Press Create

Now the screen for the transaction is shown and you can enter default values in the fields of the screen

Press Enter. Now a screen that enbles you to make further customizing (Hide, Output only, Invisible, Mandatory) if the screen fields is shown.

After you have finished customizing the screen press Enter to go to the next screen or ave and exit to save the Transaction variant

 

How to find user exits

Display the program where you are searching for and exit and search for CALL CUSTOMER-EXIT

If you know the Exit name, go to transaction CMOD. Choose menu Utillities->SAP Enhancements. Enter the exit name and press enter.

 

You will now come to a screen that shows the function module exits for the exit.

 

Using Project management of SAP Enhancements

 

We want to create a project to enahance trasnaction VA01

Go to transaction CMOD

Create a project called ZVA01

Choose the Enhancement assign radio button and press the Change button

In the first column enter V45A0002 Predefine sold-to party in sales document . Note that an enhancement can only be used i 1 project. If the enhancement is allready in use, and error message will be displayed

Press Save

Press Components. You can now see that enhancement uses user exit EXIT_SAPMV45A_002. Double click on the exit.

 

Now the function module is displayed. Double click on include ZXVVAU04 in the function module

Insert the following code into the include: E_KUNNR = '2155'.

Activate the include program. Go back to CMOD and activate the project.

Goto transaction VA01 and craete a salesorder. Note that Sold-to-party now automatically is "2155"

To run the transaction varian, you must create a new Transaction code in SE93  that referes to the Transaction variant. Choose Transaction with variant as Start object.

 

Note: The transaction variant can also be called from a program that imcludes a call to function module RS_HDSYS_CALL_TC_VARIANT

 

Can a field exit on a screen access the values entered by a user on that screen for the screen fields other than the field for which the  exit has been applied. if yes then how?

Maybe this function helps you: DYNP_VALUES_READ. It reads the dynpro-values before processing PAI.

 

What are events in dialogs?

Process Before Output and

Process After Input.

Process On Value

Process On Help

Module output.

Module input.

 

What are significance of PBO and PAI?

Before display the screen PBO is fired. This is for screen display

After giving the user input PAI is fired. This is for input validation

 

Where you will validate entries in the fields?

Entries can be validated in PAI.

You can validate in Field Exits also.

 

What is use of Chain and EndChain?

For calling a particular PAI module if any one of fields in a group meets a condition, we use to combine all such fields .

 

How to change screen dynamically?

By modifying the screen attributes.

 

How to capture changes on the screen fields? Same in case of table control?

We can capture changes on the screen fields using module on input and on request.

 

If you are validating contents of  field but user want to exit from the transaction without validating contents; How to handle this scenario?

By at exit-command we can do.

 

How to pass field values from one screen to other screen?

By using set and get parameter id statements.

 

What is the difference in using COMMIT WORK within a called transaction and within a called dialog module in an existing module.

Ans.:

Transaction: It will create a new LUW and so you have to say COMMIT WORK in a called transaction for getting any of the update statements to be fruitful inside the called transaction.

Dialog module: Since no new LUW is created, COMMIT WORK is not necessary.

 

Which 2 transaction codes are used to manage enhancements?

Ans: SMOD and CMOD

 

Which enhancement is local, which is global:   

Field Exits

Screen Exits

Program Exits

Menu Exits

 

Where can you create an enhancement to show your own F1 Help on a field?

            Ans:  in POH

 

What enhancements can be created using Cmod?

Ans: Customer Enhancements, i.e., Field Exits.

 

What is the code for showing a list produced in a dialog program?

Ans: Leave screen.

        Leave to List-processing.

Or

        Submit <program name>.

 

When is field Name1 transported to the program in this coding:

Process After Input.

Module ABC.

Field Name1 Module DEF.

 

What is the effect of SUPPRESS DIALOG in PBO?

Field Name2 Module GHI.

 

If an error message was raised in Module GHI, which fields would be ready for input?

Ans: The fields that are placed in CHAIN………ENDCHAIN.

 

In which 2 places could you set the GUI status and title bar for a modal dialog box?

 

 

 

 

What does CHAIN ....END CHAIN do?

Sometimes you want to check several fields as a group. To do this, include the fields in a FIELD statement, and enclose everything in a CHAIN-ENDCHAIN block.

Example

**** Screen flow logic: ****

CHAIN.

            FIELD: SPFLI-CARRID, SPFLI-CONNID.

              MODULE CHECK_FLIGHT.

            ENDCHAIN.

When an error is found inside a chain, the screen is re-displayed, and all fields found anywhere in the chain are input-enabled. All non-chain fields remain disabled.

 

How can you test flow logic?

Check function checks the syntax,data-consisteny and screen layout of the screen.

To test the syntax, from the menu path choose screen---->check-------> syntax.

To test the data consistency, from the menu path choose screen---->check------> consistency.

To check the layout,from ythe menu path choose screen----->check----->layout.

 

What happens if you choose hold data option in screen atributes?

To retain data entered by a user. The system automatically displays this data if the user returns to this screen.

 

What happens if you enter 0 in NEXT screen attribute?

In ABAP/4 each stackable sequence of screens is a "call mode". This is important because of the way you return from a given current sequence. To terminate a call mode and return to a suspended chain, set the "next screen" to 0 and leave to it:When you return to the suspended chain, execution resumes with the statement directly following the original CALL SCREEN statement.The original sequence of screens in a transaction is itself a calling mode. The original sequence of screens in a transaction is itself a calling mode. If you LEAVE TO SCREEN 0 in this sequence (that is, without having stacked any additional call modes), you return from the transaction altogether.

 

How many menu titles you can have in a main menu?

You can have six menus in a menu bar.In addition to this system provides two more menus ie system and help. You can have only one menu bar for a status.         

You can maintain 15 entries in a menu and upto three levels.

 

What is the difference between the "change on-input" and "Change on request" in the PAI of a screen?

 

·         ON INPUT

The ABAP/4 module is called only if the field contains a value other than its initial value. This initial value is determined by the field's data type: blanks for character fields, zeroes for numerics.

 

·         ON REQUEST

The ABAP/4 module is called only if the user has entered a value in the field value since the last screen display. The value counts as changed even if the user simply types in the value that was already there.

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