TRANSACTIONS

1 ) What is a transaction?

A transaction is dialog program that change data objects in a consistant way.


2) 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 data bases.


3. What are the basic components of dialog program?

- Screens (Dynpros)

- Each dialog in an SAP system is controlled by dynpros.A dynpros 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.


4.What is a PBO and PAI event?

PBO- Process Before Output-It determines the flow logic before displaying the screen.

PAI-Process After Input-It determines the flow logic after the display of the screen and after receiving inputs from the User.


5. What is dynpro? What are its components ?

- A dynpro (Dynamic Program) consists of a screen and its flow logic and controls exactly one-dialog steps.

- The different components of the dynpro are :

Flow Logic: calls of the ABAP/4 modules for a screen .

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

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

Fields attributes: Definition of the attributes of the individual fields on a screen.


6. What is a 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 on interactive modules.


7..Can we use WRITE statements 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 fields names with ABAP/4 variable names.

If both names are the same, itTransfers screen fields values to ABAP/4 programs fields and Vice Versa. This happens immediately after displaying the screen.



8. Can we use flow logic control key words in ABAP/4 and vice-versa?

- The flow control of a dynpro consists os a few statements that syntactically ressemble ABAP/4 statements .However ,we cannot use flow control keywords in ABAP/4 and vice-versa.


9 What is GUI status? How to create /Edit GUI status?

-A GUI status is a subset of the interface elements used for a certain screen.The status comprises those elements that are currently needed by the transaction .The GUI status for a transaction may be composed of the following elements:

-Title bar.

-Mneu bar.

-Application tool bar

-Push buttons.

To create and edit GUI status and GUI title,we use the Menu Painter.


10. How does the interection between the Dynpro and the ABAP/4 Modules takes place?

-A transaction is a collection os screens and ABAP/4 routines, controlled and executed by a Dialog processor. The Dialog processor processes screen after the screen, thereby triggering the appropriate ABAP/4 processing of each screen .

For each screen,the system executes the flow logic that contains the corresponding ABAP/4 processing.The controls passes from screen flow logic to ABAP/4 code and back.


11. 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 data entered by the user and a function code.

A functioncode is a technical name that has been allocated in a screen Painter or Menu Painter to a meny entry,a push button,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.


12.What is to be defined for a push button fields in the screen attributes?

- A function code has to be defined in the screen attributes for the push buttons in a screen.



13. How are the function code handles 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 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.



14.What controls the screen flow?

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



15.The Function code currently active is ascertained by what Variable?

- The function code currently active in a Program can be ascertained from the SY-UCOMM Variable.



16.The function code currently active is ascertained by what variable ?

- By SY-UCOMM Variable.


17.What are the “field” and “chain” Statements?

- The FIELD and CHAIN flow logic statements let you Program Your own 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.



18.What is an “on input filed” statements?

- ON INPUT The ABAP/4 module is called only if a field contains the Value other than the initial Value.

This initial Value is determined by the filed’s Dta Type: blanks for character Fields,Zeroes for numerics. If the user changes the Fields Value back t o its initial value,ON INPUT does not trigger a call.



19.What is an “on request Field” statement?

- ON REQUEST

The ABAP/4 Module is called only if the user has entered the 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 .In general ,the ON REQUEST condition is triggered through any Form of” MANUAL INPUT’.



20.What is an on”*-input filed” statement?

ON *-INPUT

- The ABAP/4 module is called if the user has entered the “*” 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.


21.What are conditional chain statement?

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(blank 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.


22.What is “at exit-command:?

The flowlogic 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 fields checks.


23.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 .



24.What are the different message types available in the ABAP/4 ?

- There are 5 types of message types available.

- E: ERROR

- W-WARNING

- I –INFORMATION

- A-ABNORMAL TERMINATION.

- S-SUCCESS


25)Of the two “ next screen “ attributes the attributes that has more priority is -------------------.

Dynamic.



26.Navigation to a subsequent screen can be specified statically/dynamically. (TRUE/FALSE).

TRUE.


27.Dynamic screen sequence for a screen can be set using ------------- and ----------------- commands

Set Screen, Call screen.


28.. The commands through Which an ABAP/4 Module can “branch to “ or “call” the next screen are

1.------------,2--------------,3---------------,4------------.-
Set screen,Call screen ,Leave screen, Leave to screen .


29. What is 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 sonn as th e 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 (screen chain) is called .The called can then return to the suspended chain with the statement LEAVE SCREEN TO SCREEN 0 .Sometime we might want to let an user call a pop up screen from the main application screen to let him enter secondary information.After they have completed their enteries, 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 intp the current one.