Extend a Custom Core Data Service in ABAP Environment

1. Open Eclipse and connect to your system.

2. Right-click on the package ZLOCAL and choose New > ABAP Package from the context menu.

3. Create your own ABAP development package Z_Travel_### as a sub package of ZLOCAL.

   • Name: Z_Travel_###
   • Description: My travel package
   • Select the Add to favorite packages box

4. Click Next.

   

5. Select package properties and click Next.

   • Software Component: ZLOCAL
   

6. Select a transport request or create new and click Finish.

   

Create a Structure with a field Description.

1. Right-click on your ABAP package Z_Travel_### and select New > Other ABAP Repository Object from the context menu.

   

2. Enter the filter text Structure > Structure, then choose Next.

3. Enter a name such as ZTravel_struc_### - always replacing ### with your initials or group number - and a description, then choose Next.

   

4. Accept the proposed transport request and click Finish.

5. Replace the default code with the code snippet provided below and replace all occurrences of the placeholder ### with your group ID using the Replace All function (CTRL+F).

   ABAP

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   @EndUserText.label : 'Structure of Travel Data'
   @AbapCatalog.enhancement.category : #EXTENSIBLE_ANY
   @AbapCatalog.enhancement.fieldSuffix : 'ZAC'
   @AbapCatalog.enhancement.quotaMaximumFields : 350
   @AbapCatalog.enhancement.quotaMaximumBytes : 3500
   define structure ztravel_struc_### {
   
     description : /dmo/description;
   
   }
   

6. Save

   
   and activate
   
   the changes.

Create a database table to store the Travel data. This Travel table contains Travel ID, Total Price and Currency Code.

1. Right-click on your ABAP package Z_Travel_### and select New > Other ABAP Repository Object from the context menu.

   

2. Enter the filter text Table > Database table, then choose Next.

3. Enter a name such as ZTravel_### - always replacing ### with your initials or group number - and a description, then choose Next.

   

4. Accept the proposed transport request and click Finish.

5. Replace the default code with the code snippet provided below and replace all occurrences of the placeholder ### with your group ID using the Replace All function (CTRL+F).

   ABAP

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   @EndUserText.label : 'Travel data for Extensibility'
   @AbapCatalog.enhancement.category : #EXTENSIBLE_ANY
   @AbapCatalog.tableCategory : #TRANSPARENT
   @AbapCatalog.deliveryClass : #A
   @AbapCatalog.dataMaintenance : #RESTRICTED
   define table ztravel_### {
   
     key client    : abap.clnt not null;
     key travel_id : /dmo/travel_id not null;
     @Semantics.amount.currencyCode : 'ztravel_###.currency_code'
     total_price   : /dmo/total_price;
     currency_code : /dmo/currency_code;
     include ztravel_struc_###;
   
   }
   

6. Save

   
   and activate
   
   the changes.

Create an ABAP class to generate demo travel data.

1. Right-click on your ABAP package Z_Travel_### and select New > ABAP Class from the context menu.

2. Enter a name such as ztravel_fill_data_### - always replacing ### with your initials or group number - and a description, then choose Next.

   

3. Accept the proposed transport request and click Finish.

4. Replace the default code with the code snippet provided below and replace all occurrences of the placeholder ### with your group ID using the Replace All function (CTRL+F).

   ABAP

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   CLASS ztravel_fill_data_### DEFINITION
     PUBLIC
     FINAL
     CREATE PUBLIC .
   
     PUBLIC SECTION.
       INTERFACES if_oo_adt_classrun.
     PROTECTED SECTION.
     PRIVATE SECTION.
   ENDCLASS.
   
   CLASS ztravel_fill_data_### IMPLEMENTATION.
   
     METHOD if_oo_adt_classrun~main.
   
   *   clear data
       DELETE FROM ztravel_###.
   
       "insert travel demo data
   
       INSERT ztravel_### FROM (
       SELECT
         FROM /dmo/travel AS travel
         FIELDS
         travel~travel_id AS travel_id,
         travel~total_price AS total_price,
         travel~currency_code AS currency_code,
         travel~description AS description
       ).
       COMMIT WORK.
       out->write( | Data generated for table ztravel_### | ).
     ENDMETHOD.
   ENDCLASS.
   

5. Save
   
   and activate
   
   the changes.

6. Run your console application. For that, select your ABAP class ztravel_fill_data_###, select the run button > Run As > ABAP Application (Console) F9 or press F9.

   

Create a CDS view ZITravel_### based on the database table ZTravel_###

1. Right-click on your ABAP package Z_Travel_### and select New > Data Definition from the context menu.

   

2. Enter a Name such as ZITravel_### - always replacing ### with your initials or group number - and a description, then choose Next.

   

3. Accept the proposed transport request and click Finish.

4. Replace the default code with the code snippet provided below and replace all occurrences of the placeholder ### with your group ID using the Replace All function (CTRL+F).

   ABAP

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       @AbapCatalog.viewEnhancementCategory: [#PROJECTION_LIST]
       @AccessControl.authorizationCheck: #NOT_REQUIRED
       @EndUserText.label: 'Travel View Entity'
       @Metadata.ignorePropagatedAnnotations: true
       @AbapCatalog.extensibility: {
         extensible: true,
         elementSuffix: 'ZAC',
         quota: {
           maximumFields: 500,
           maximumBytes: 5000
         },
         dataSources: [ '_Travel' ]
       }
       define view entity ZITRAVEL_###
         as select from ztravel_### as _Travel
       {
         key travel_id     as TravelId,
             description   as Description,
             @Semantics.amount.currencyCode: 'CurrencyCode'
             total_price   as TotalPrice,
             currency_code as CurrencyCode
       }
   

5. Save
   
   and activate
   
   the CDS view.

6. Click anywhere in the editor and choose Open With > Data Preview from the context menu.

   

Let us consider a database table that is defined by a software provider, for example, SAP. A customer or partner wants to add fields to this database table.

Instead of adding the fields to the database table definition in the dictionary, they create an append structure. The append structure is a separate dictionary object, owned and maintained by the customer or partner.

1. Right-click on the structure ZTravel_struc_### and select New > Append Structure from the context menu.

   

2. Enter a Name such as ZTravel_struc_ext_###- always replacing ### with your initials or group number - and a description, then choose Next.

   

3. Accept the proposed transport request and choose Finish.

4. Replace the default code with the code snippet provided below and replace all occurrences of the placeholder ### with your group ID using the Replace All function (CTRL+F).

   ABAP

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   @EndUserText.label : 'Structure for Travel table extension'
   @AbapCatalog.enhancement.category : #NOT_EXTENSIBLE
   extend type ztravel_struc_### with ztravel_struc_ext_### {
   
   zztraveltype_zac : /dmo/carrier_name;
   
   }
   

5. Save

   
   and activate
   
   .

The new field zztraveltype_zac should be filled with the below logic in the ABAP class.

If `total_price` > 4500, set Travel Type to 'Business'.
Else, if `total_price` > 3000, set Travel Type to 'Premium Economy'.
Otherwise, set Travel Type to 'Economy'

1. Right-click on your ABAP package Z_Travel_### and select New > ABAP Class from the context menu.

2. Enter a Name such as ztravel_ext_data_### - always replacing ### with your initials or group number - and a description, then choose Next.

3. Accept the proposed transport request and click Finish.

4. Replace the default code with the code snippet provided below and replace all occurrences of the placeholder ### with your group ID using the Replace All function (CTRL+F).

   ABAP

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     CLASS ztravel_ext_data_### DEFINITION
     PUBLIC
     FINAL
     CREATE PUBLIC .
   
     PUBLIC SECTION.
       INTERFACES if_oo_adt_classrun.
     PROTECTED SECTION.
     PRIVATE SECTION.
   ENDCLASS.
   
   CLASS ztravel_ext_data_### IMPLEMENTATION.
   
     METHOD if_oo_adt_classrun~main.
       DATA: lt_travel TYPE TABLE OF ztravel_###,
             ls_travel TYPE ztravel_###.
   
       " Select existing data from the table
       SELECT * FROM ztravel_### INTO TABLE @lt_travel.
   
       " Loop through the data and update the new field based on the logic
       LOOP AT lt_travel INTO ls_travel.
         IF ls_travel-total_price > 4500.
           ls_travel-zztraveltype_zac = 'Business'.
         ELSEIF ls_travel-total_price > 3000 AND ls_travel-total_price < 4500.
           ls_travel-zzTravelType_zac = 'Premium Economy'.
         ELSE.
           ls_travel-zzTravelType_zac = 'Economy'.
         ENDIF.
   
         " Update the table with the new value
         MODIFY ztravel_### FROM @ls_travel.
       ENDLOOP.
       out->write( |Table updated| ).
     ENDMETHOD.
   ENDCLASS.
   

5. Save
   
   and activate
   
   the changes.

6. Run your console application. For that, select your ABAP class ztravel_ext_data_###, select the run button > Run As > ABAP Application (Console) F9 or press F9.

1. Right-click on the CDS View ZITravel_### and select New > Data Definition from the context menu.

2. Enter a Name such as ZITravel_Ext_### - always replacing ### with your initials or group number - and a description, then choose Next.

   

3. Accept the proposed transport request and click Finish.

4. Replace the default code with the code snippet provided below and replace all occurrences of the placeholder ### with your group ID using the Replace All function (CTRL+F).

   ABAP

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       extend view entity ZITRAVEL_### with {
       _Travel.zztraveltype_zac as ZZTravelTypeZAC
       }
   

5. Save

   
   and activate
   
   the changes.

6. Click anywhere in the editor and choose Open With > Data Preview from the context menu. The newly added field comes up in the data preview with the data filled.

While in the previous step, we added the logic in the ABAP class which updates the database table, in this step we will check how to dynamically calculate the values and add in a new field in the extended CDS view.

1. Add a new field ZZDiscPriceZAC with the condition: If total_price > 1000, apply a 10% discount.

2. Copy the below code snippet and add below the exposed field ZZTravelTypeZAC

   ABAP

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     @Semantics.amount.currencyCode: 'CurrencyCode'
     case
       when _Travel.total_price > 1000
         then  cast( _Travel.total_price as abap.dec(15,1) ) * cast( '0.9' as abap.dec(2,1) )
       else cast( _Travel.total_price as abap.dec(15,1) )
     end                      as ZZDiscPriceZAC
   

3. Save

   
   and activate
   
   the changes.

4. Click anywhere in the editor and choose Open With > Data Preview from the context menu. A new field ZZDiscPriceZAC comes up with the dynamic calculation.

You will expose FlightDate field from /DMO/I_BOOKING_U and calculate the number of days left from today until the flight date.

1. Below is the complete code of the extended view entity . Replace all occurrences of the placeholder ### with your group ID using the Replace All function (CTRL+F).

   ABAP

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     extend view entity ZITRAVEL_### with
   
     association [1..1] to /DMO/I_Booking_U as _ZZBooking on $projection.TravelId = _ZZBooking.TravelID
     {
       _Travel.zztraveltype_zac as ZZTravelTypeZAC,
   
       @Semantics.amount.currencyCode: 'CurrencyCode'
       case
         when _Travel.total_price > 1000
           then  cast( _Travel.total_price as abap.dec(15,1) ) * cast( '0.9' as abap.dec(2,1) )
         else cast( _Travel.total_price as abap.dec(15,1) )
       end                      as ZZDiscPriceZAC,
   
       _ZZBooking.FlightDate    as ZZFlightDateZAC,
   
       case
         when _ZZBooking.FlightDate > $session.system_date then
   
         dats_days_between( _ZZBooking.FlightDate, $session.system_date )
   
       else 0
       end                      as ZZDaysRemainingZAC
     }
   

2. Save

   
   and activate
   
   the changes.

3. Click anywhere in the editor and choose Open With > Data Preview from the context menu. There will be 4 custom fields added through Developer Extensibility.

• Learning Journey

• Develop Extensibility-Enablement