topic Re: Class Inheritance? in Application Development and Automation Discussions

Class Inheritance?

Former Member — Wed, 06 Feb 2008 09:14:27 GMT

Hello!

I've created one class via SE24. Now I have a second class. This - second class - have to have an inheritance from first class. Where can I input it in SE24?

Thanks!!

Re: Class Inheritance?

former_member182670 — Wed, 06 Feb 2008 09:30:02 GMT

When you create class there is a popup dialog.

Next to class name there is a button with inheritance symbol (triangle)

When you press it field for super class will appear.

Re: Class Inheritance?

Former Member — Wed, 06 Feb 2008 09:34:07 GMT

Hi,

Please go through this example:

"Example :

REPORT demo_inheritance.

CLASS counter DEFINITION.

PUBLIC SECTION.

METHODS: set IMPORTING value(set_value) TYPE i,

increment,

get EXPORTING value(get_value) TYPE i.

PROTECTED SECTION .

DATA count TYPE i.

ENDCLASS.

CLASS counter IMPLEMENTATION.

METHOD set.

count = set_value.

ENDMETHOD.

METHOD increment.

ADD 1 TO count.

ENDMETHOD.

METHOD get.

get_value = count.

ENDMETHOD.

ENDCLASS.

CLASS counter_ten DEFINITION INHERITING FROM counter.

PUBLIC SECTION.

METHODS increment REDEFINITION .

DATA count_ten.

ENDCLASS.

CLASS counter_ten IMPLEMENTATION.

METHOD increment.

DATA modulo TYPE I.

CALL METHOD super->increment .

write / count.

modulo = count mod 10.

IF modulo = 0.

count_ten = count_ten + 1.

write count_ten.

ENDIF.

ENDMETHOD.

ENDCLASS.

DATA: count TYPE REF TO counter,

number TYPE i VALUE 5.

START-OF-SELECTION.

CREATE OBJECT count TYPE counter_ten .

CALL METHOD count->set EXPORTING set_value = number.

DO 20 TIMES.

CALL METHOD count->increment.

ENDDO.

persistance class

There is a way to avoid building a fully object-oriented program while still working with non-object-oriented relational database. The object services layer now provides a persistence framework that closes the object-relational gap.

You no longer need to write SQL code as objects are transparently loaded from the database when needed. You must create a persistent class. Choose transaction SE24 and create a persistent class; this class must be protected.

steps :

Go to se 24 - choose persistence class

it will be always protected class.

next screen will give u the persistence button when u click on that it will ask u to

add the table or struture.

now u can see two division of the screen where bottom portion of the screen will list uall the fields available and u need to double click and map to the top portion.

Save the persistence class and hit back button..

Whenever u create persistence class zcl_example_persist - it will create two classes - zca_example_persist

and zcb_example_persist automatically

Where zca_example_persist is the agent class and zcb_example_persist is base agent class..

Save and activate.

Activate the whole class. Now that we have a persistent object to access the database table SFLIGHT, we must access it in a program. Here is a small example to read/write data into SFLIGHT using persistent objects.

REPORT ZPERSISTENCECLASS.

data : l_flight type ref to zcl_persist.

data : l_flight_agent type ref to zca_persist.

data : l_seatsfree type i.

data : l_seatsocc type i.

l_flight_agent = zca_persist=>agent.

CATCH CX_OS_OBJECT_NOT_FOUND .

*ENDTRY.

*TRY.

CALL METHOD L_FLIGHT_AGENT->GET_PERSISTENT

EXPORTING

I_CARRID = 'LH'

I_CONNID = '0400'

I_FLDATE = '20060701'

RECEIVING

RESULT = l_flight

CATCH CX_OS_OBJECT_NOT_FOUND .

*ENDTRY.

l_seatsfree = L_FLIGHT->GET_SEATSMAX( ) - L_FLIGHT->GET_SEATSOCC( ).

if l_seatsfree > 0.

l_seatsfree = L_FLIGHT->GET_SEATSOCC( ) + 1.

l_flight->set_seatsocc( l_seatsfree ).

endif.

Reward Points if found helpfull..

Cheers,

Chandra Sekhar.

Re: Class Inheritance?

Former Member — Wed, 06 Feb 2008 09:34:21 GMT

While creating the 1st class, we have to UBCHECK the FINAL check box.

If it is checked, we cant inherit from this class

Reward if useful

Narendra

Re: Class Inheritance?

Former Member — Wed, 06 Feb 2008 09:34:54 GMT

1.goto se24

2. Specify a class name and create

3. specify the object type as CLASS

4. now on the rt side of your class there is triangle button.clickon that

5. as soon as u click on that it will ask for a superclass

this how u can do it.

reward pts if useful.

Re: Class Inheritance?

Former Member — Wed, 06 Feb 2008 09:35:48 GMT

Hi,

While creating a new class you can find a button for 'Create Inheritance' at the right corner against the class name. Here you can input the super class name for inheritance.

Thanks,

Subathra

Re: Class Inheritance?

Former Member — Wed, 06 Feb 2008 09:42:14 GMT

first create class1 after that u create class2 and go to the properties tab of the class2 there u find three buttons subclass,super class and undo inheritance. here u select super class button. when ever u select SUPER CALSS button then automatically one text box appears there u enter the class1.

this is the way we can set the super class.

Regards,

Ashok