ex3

Exercise 3 - CDS Data Model Projection

Introduction

In the previous exercise you've created the travel and the booking interface views of the CDS data model for the travel app (see Exercise 2).

In this exercise you will define the CDS data model projection for your travel app on top of the CDS data model.

Further information can be found here: CDS Projection View

Exercise 3.1 - Create the Travel Projection View

1. Right-click on your travel BO view (aka interface view) ZI_RAP_Travel_#### and choose New Data Definition from the context menu.

   

2. Maintain ZC_RAP_Travel_#### (where #### is your group ID) as name and a description (e.g. Travel BO projection view) in the creation wizard and choose Next > to continue.

   

3. Assign a transport request and choose Finish (please note: clicking on Next in the Selection of Transport Request step, you get to the optional Templates step in which you can choose from predefined templates).

   Replace the travel data definition in the editor with the code snippet provided below and replace all occurrences of #### with your group ID.

   Save the changes, but DO NOT yet activate the travel BO projection view.

    @EndUserText.label: 'Travel BO projection view'
    @AccessControl.authorizationCheck: #CHECK
    @Search.searchable: true
    @Metadata.allowExtensions: true
   
    @ObjectModel.semanticKey: ['TravelID']
   
    define root view entity ZC_RAP_Travel_####
      as projection on ZI_RAP_Travel_#### as Travel
    {
      key TravelUUID,
          @Search.defaultSearchElement: true
          TravelID,
          @Consumption.valueHelpDefinition: [{ entity: { name: '/DMO/I_Agency', element: 'AgencyID'} }]
          @ObjectModel.text.element: ['AgencyName']
          @Search.defaultSearchElement: true
          AgencyID,
          _Agency.Name       as AgencyName,
          @Consumption.valueHelpDefinition: [{ entity: { name: '/DMO/I_Customer', element: 'CustomerID'} }]
          @ObjectModel.text.element: ['CustomerName']
          @Search.defaultSearchElement: true
          CustomerID,
          _Customer.LastName as CustomerName,
          BeginDate,
          EndDate,
          @Semantics.amount.currencyCode: 'CurrencyCode'
          BookingFee,
          @Semantics.amount.currencyCode: 'CurrencyCode'
          TotalPrice,
          @Consumption.valueHelpDefinition: [{ entity: { name: 'I_Currency', element: 'Currency'} }]
          CurrencyCode,
          Description,
          TravelStatus,
          LastChangedAt,
          LocalLastChangedAt,
   
          /* Associations */
          _Agency,
          _Booking : redirected to composition child ZC_RAP_Booking_####,
          _Currency,
          _Customer   
    }
    

   The data definition should look as follows:

   

   The Travel projection view exposes all associations that are defined in the underlying travel interface view. However, the composition to the booking BO child node (_Booking) must be redirected to the Booking BO projection view. This is done using the redirected to composition child statement.

Exercise 3.2 - Create the Booking Projection View

1. Right-click on your Booking BO view (aka interface view) ZI_RAP_BOOKING_#### and choose New Data Definition from the context menu.

   

2. Maintain ZC_RAP_BOOKING_#### (where #### is your group ID) as name and a description (e.g. Booking BO projection view) in the creation wizard and choose Next > to continue.

   

3. Assign a transport request and choose Finish. Replace the booking data definition in the editor with the code snippet provided below and replace all occurrences of #### with your group ID.

   Save the changes, but DO NOT yet activate the booking BO projection view.

    @EndUserText.label: 'Booking BO projection view'
    @AccessControl.authorizationCheck: #CHECK
    @Search.searchable: true
    @Metadata.allowExtensions: true
   
    define view entity ZC_RAP_Booking_####
      as projection on ZI_RAP_Booking_#### as Booking
    {
      key BookingUUID,
          TravelUUID,
          @Search.defaultSearchElement: true
          BookingID,
          BookingDate,
          @Consumption.valueHelpDefinition: [{ entity : {name: '/DMO/I_Customer', element: 'CustomerID'  } }]
          @ObjectModel.text.element: ['CustomerName']
          @Search.defaultSearchElement: true
          CustomerID,
          _Customer.LastName as CustomerName,
          @Consumption.valueHelpDefinition: [{entity: {name: '/DMO/I_Carrier', element: 'AirlineID' }}]
          @ObjectModel.text.element: ['CarrierName']
          CarrierID,
          _Carrier.Name      as CarrierName,
          @Consumption.valueHelpDefinition: [ {entity: {name: '/DMO/I_Flight', element: 'ConnectionID'},
                                               additionalBinding: [ { localElement: 'CarrierID',    element: 'AirlineID' },
                                                                    { localElement: 'FlightDate',   element: 'FlightDate',   usage: #RESULT},
                                                                    { localElement: 'FlightPrice',  element: 'Price',        usage: #RESULT },
                                                                    { localElement: 'CurrencyCode', element: 'CurrencyCode', usage: #RESULT } ] } ]
          ConnectionID,
          FlightDate,
          @Semantics.amount.currencyCode: 'CurrencyCode'
          FlightPrice,
          @Consumption.valueHelpDefinition: [{entity: {name: 'I_Currency', element: 'Currency' }}]
          CurrencyCode,
          LocalLastChangedAt,
   
          /* associations */
          _Travel : redirected to parent ZC_RAP_Travel_####,
          _Customer,
          _Carrier,
          _Connection,
          _Flight
   
    }
    

   The data definition now looks as follows:

   

   The association to the travel BO parent node has been redirected to the Travel BO projection view using the redirect to parent statement.

Exercise 3.3 - Activate the CDS Data Model Projection

To avoid error during the activation, both new CDS projection views – i.e. Travel view and Booking view – must be activated together for the first time.

1. Choose Activate All or use the shortcut Ctrl+Shift+F3 to active both CDS views together.

   

   Your projected CDS data model consisting of the Travel BO projection view and the Booking BO projection view is now activated.

Summary

Now that you've...

• created both CDS projection views and
• activated them using mass activation,

you can continue with - Exercise 4 - Metadata Extensions

Appendix

Find the source code for the CDS views in the sources folder. Don't forget to replace the placeholder #### with your group ID.

• CDS View ZC_RAP_TRAVEL_####
• CDS View ZC_RAP_BOOKING_####