0601 abap objects

7/27/2019 0601 ABAP Objects

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ABAP Objects


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Describe the Advantages of Object Orientation

Define Classes, Attributes, and Methods

Define the Reference Concept

Describe Interfaces and Events

Topic Objectives


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Advantages of Object Orientation

Encapsulation Interface Creation

Integration of ExternalObject Models

Distribution

Support of GUIand Workflow

Generic Programmingand Reusability


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Encapsulation

Object: Flight

Method: book

Data: passenger_list

Program: . . .

add 1 to passenger_list

Program: . . .

Read table passenger_list

No

access


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Function Modules vs. Objects

GUI SessionInternal Session of

ABAP Program

Function

Group1 withdata

Function

Group Nwith data

ABAP Program with data

Internal Session ofABAP ProgramGUI Session

ABAP Program with data

Function Group/ Module Objects

Objects

of Class 1with data

Objects of

Class Nwith data


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Overview of Object-Oriented

Concepts

A object is a self-contained entity having astate, a behavior, and an identity.


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Object Attributes

PassengerList

Public

Access

Private Access

CARRID

CONNID

Method: BOOK

LH

0400FLDATE1998-

01-

26

MillerCarter

Smith


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Objects Belonging to Classes

InstancesInstances

Class Flight Class Hotel


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Classes

CLASS DEFINITION.

* INHERITING FROM -- available in a later 4.0 version

PUBLIC SECTION.

definition of components visible outside the class

PROTECTED SECTION.

definition of components only visible to subclasses of

this class.

PRIVATE SECTION.

definition of components only visible within the class

ENDCLASS.

CLASS IMPLEMENTATION.

method implementations

ENDCLASS.


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Class Components: Attributes &

Methods

{DATA | CLASS-DATA} attr TYPE type

[ VALUE val ]

[ READ-ONLY ]

[ VIRTUAL [ SET-METHOD set-method ]

[ GET-METHOD get-method ] ].

CONSTANTS const TYPE type VALUE val.

{METHODS | CLASS-METHODS} method

[ IMPORTING ][ EXPORTING ]

[ CHANGING ]

[ EXCEPTIONS ]

[ RETURNING result TYPE t ].


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Reference Concept

Object ReferenceObject Reference

Instances


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The Reference Concept Example

REPORT Flightdemo.

TYPES: tpassenger(20).

CLASS c_flight DEFINITION.

PUBLIC SECTION.

DATA: carrid like spfli-carrid,

connid like spfli-connid,

fldate like spfli-fldate.

METHODS: book IMPORTING passenger TYPE tpassenger.

PRIVATE SECTION.

DATA: passengerlist type tpassenger occurs 10.ENDCLASS.

CLASS c_flight IMPLEMENTATION.

METHOD book.

APPEND passenger to passengerlist.

ENDMETHOD.

ENDCLASS.

START-OF-SELECTION.DATA: flight TYPE REF to c_flight.

CREATE OBJECT flight.

Flight->carrid = LH.

Flight->connid = 0567.

Flight->fldate = 19970908.

CALL METHOD flight->book EXPORTING passenger = Peter Miller.

b


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Interfaces

InstancesInstances

Class FlightClass Hotel

Interface Reservation

G i P i ith


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Generic Programming with

Interfaces

INTERFACE interface.

[ INTERFACES ]

[ ]

ENDINTERFACE.


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Example of Programming Interface


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Events

Event Source

Event raising classEvent Handling Classes

Event Table


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Event & Event Handlers Example

CLASS CGUIbutton DEFINITION.

PUBLIC SECTION.METHODS: SetLabel

IMPORTING

txt TYPE .

EVENTS: Clicked

EXPORTING

doubleclick TYPE I.

ENDCLASS.

CLASS CGUIbutton IMPLEMENTATION.

METHOD anymethod.

RAISE EVENT Clicked

EXPORTING doubleclick = 0.

ENDMETHOD.

ENDCLASS.

CLASS window1 DEFINITION.

PUBLIC SECTION.

INTERFACES EVENTS OF CGUIbuttonAS: OKBtn, CancelBtn.

DATA: OK TYPE REF TO

CGUIbutton.

ENDCLASS.

CLASS window1 IMPLEMENTATION.

METHOD init.

CREATE OBJECT OK.SET HANDLEROKBtn FOR EVENTS

OF OK.

ENDMETHOD.

METHOD OKBtn~Clicked.

If doubleclick = 1.

Endif.ENDMETHOD.

METHOD CancelBtn~Clicked.

ENDMETHOD.

ENDCLASS.


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Exercise 47 - Creating and Using a Class, 60 minutes

Exercise


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Any questions?

Questions and Answers

0601 abap objects

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