How to Create RAP Business Events in SAP BTP ABAP Environment

To produce and raise an event you need first to define your RAP Business Object which produce the event. For this, you will create a simple online shop application. The event will be sent whenever a new order is created.

1. Open ADT and open your SAP BTP ABAP environment system.

2. If you do not have an ABAP Package create a new one. Please be sure if your package name is with Z like

   • Name: ZEVENT_EXPOSURE_###
   • Description: define a RAP event
   

3. Right-click on your package and create a new database table

   • Name: ZONLINESHOP_###
   • Description: DB for onlineshop
   
   

4. Copy the code below to the Database and replace ### with your number

   ZONLINESHOP_###

   Copy

   define table zonlineshop_### {
   key client     : abap.clnt not null;
   key order_uuid : sysuuid_x16 not null;
   order_id       : abap.char(10) not null;
   ordereditem    : abap.char(10) not null;
   deliverydate   : abap.dats;
   creationdate   : abap.dats;
   }
   

5. Save and activate your table.

   

1. Right-click on your package and create a data definition

   • Name: ZI_ONLINE_SHOP_###
   • Description: data model for online shop
   
   

2. Copy the code below to your CDS data model and replace ### with your number

   ZI_ONLINE_SHOP_###

   Copy

   @AbapCatalog.viewEnhancementCategory: [#NONE]
   @AccessControl.authorizationCheck: #NOT_REQUIRED
   @EndUserText.label: 'Data model for online shop'
   @Metadata.ignorePropagatedAnnotations: true
   @ObjectModel.usageType:{
   serviceQuality: #X,
   sizeCategory: #S,
   dataClass: #MIXED
   }
      define root view entity zi_online_shop_### as select from zonlineshop_### {
      key order_uuid as Order_Uuid,
      order_id as Order_Id,
      ordereditem as Ordereditem,
      deliverydate as Deliverydate,
      creationdate as Creationdate  
     }
   

3. Save and activate your data model.

   

4. Right-click on your package and create a new data definition

   • Name: ZC_ONLINE_SHOP_###
   • Description: projection view for online shop
   

5. After choosing a transport request click Next and choose Define Projection View

   
   

6. Copy the code below to your projection view and replace ### with your number.

   ZC_ONLINE_SHOP_###

   Copy

   @EndUserText.label: 'projection view for online shop'
   @AccessControl.authorizationCheck: #NOT_REQUIRED
   @AbapCatalog.viewEnhancementCategory: [#NONE]
   @Search.searchable: true
   @UI: { headerInfo: { typeName: 'Online Shop',
                       typeNamePlural: 'Online Shop',
                       title: { type: #STANDARD, label: 'Online Shop', value: 'order_id' } },
   
         presentationVariant: [{ sortOrder: [{ by: 'Creationdate',
                                               direction: #DESC }] }] }
   define root view entity zc_online_shop_###
   as projection on ZI_ONLINE_SHOP_###
   {
       @UI.facet: [          { id:                  'Orders',
                                     purpose:         #STANDARD,
                                     type:            #IDENTIFICATION_REFERENCE,
                                     label:           'Order',
                                     position:        10 }      ]
   key Order_Uuid,
   
       @UI: { lineItem:       [ { position: 10,label: 'order id', importance: #HIGH } ],
                 identification: [ { position: 10, label: 'order id' } ] }
       @Search.defaultSearchElement: true
       Order_Id,
   
       @UI: { lineItem:       [ { position: 20,label: 'Ordered item', importance: #HIGH } ],
               identification: [ { position: 20, label: 'Ordered item' } ] }
       @Search.defaultSearchElement: true
       Ordereditem,
   
       Deliverydate as Deliverydate,
   
       @UI: { lineItem:       [ { position: 50,label: 'Creation date', importance: #HIGH },
                                 { type: #FOR_ACTION, dataAction: 'update_inforecord', label: 'Update IR' } ],
               identification: [ { position: 50, label: 'Creation date' } ] }
       Creationdate as Creationdate
   }
   

   Add root in the line of define view entity

7. Save and activate your projection view.

   

1. Right-click on your data definition ZI_ONLINE_SHOP_### and select New Behavior Definition.

   

   Event is triggered in a save sequence. So, to raise an event, you need to enhance the existing behavior definition further with additional save phrase.
   Copy the copy below to your behavior definition and replace ### with your number

   ZI_ONLINE_SHOP_###

   Copy

   managed with additional save implementation  in class ZCL_online_shop_### unique;
   strict;
   define behavior for ZI_online_shop_### alias Online_Shop
   persistent table ZONLINESHOP_###
   lock master
   authorization master ( instance )
   {
     field ( numbering : managed, readonly ) order_Uuid;
     field ( mandatory ) Ordereditem;
     field ( readonly ) Creationdate, order_id, deliverydate;
     determination calculate_order_id on modify { create; }
   
     create;
     update;
     delete;
   }
   

2. Now you add a new event to the business object as well. Here, you will create an event which is raised when a new item is ordered. You can call the event as ItemIsOrdered. To do so, add this code line to your behavior definition

     event ItemIsOrdered parameter ZD_ItemOrdered_###;
   

   Your behavior definition will be looking like this:

   

   Save, but don’t activate your changes yet.

3. In addition, you can provide further information like the name of the item which is ordered in your message. This can be done via a parameter define as a data definition (abstract entity) called ZD_ItemOrdered.

   
   

4. Copy the code below in this definition. Do not forget to save and activate.

   ZD_ItemOrdered_###

   Copy

   @EndUserText.label: 'event parameter'
   define abstract entity ZD_ItemOrdered_###
   {
     ItemName : abap.char(25);
   }
   

   

   Save and activate your data definition ZD_ItemOrdered_### and behavior definition ZI_ONLINE_SHOP_###.

1. In your behavior definition ZI_ONLINE_SHOP_### set the cursor before the implementation class ZCL_online_shop_### and click CTRL + 1. Double-click on Create behavior implementation class ZCL_online_shop_### to create your implementation class.

   
   
   

2. In this class navigate to Local Types and add the implementation for method calculate_order_id which fill the fields of order id and the creation date as the order is created (optional).

   
   calculate_order_id

   Copy

   METHOD calculate_order_id.
   DATA:
   online_shops TYPE TABLE FOR UPDATE zi_online_shop_###,
   online_shop  TYPE STRUCTURE FOR UPDATE zi_online_shop_###.
   * delete from zonlineshop_### UP TO 15 ROWS.
   SELECT MAX( order_id ) FROM zonlineshop_### INTO @DATA(max_order_id).
   READ ENTITIES OF zi_online_shop_### IN LOCAL MODE
   ENTITY Online_Shop
   ALL FIELDS
   WITH CORRESPONDING #( keys )
   RESULT DATA(lt_online_shop_result)
   FAILED DATA(lt_failed)
   REPORTED DATA(lt_reported).
   DATA(today) = cl_abap_context_info=>get_system_date( ).
   LOOP AT lt_online_shop_result INTO DATA(online_shop_read).
     max_order_id += 1.
     online_shop = CORRESPONDING #( online_shop_read ).
     online_shop-order_id = max_order_id.
     online_shop-Creationdate = today.
     online_shop-Deliverydate = today + 10.
     APPEND online_shop TO online_shops.
   ENDLOOP.
   
   MODIFY ENTITIES OF zi_online_shop_### IN LOCAL MODE
   ENTITY Online_Shop UPDATE SET FIELDS WITH online_shops
   MAPPED DATA(ls_mapped_modify)
   FAILED DATA(lt_failed_modify)
   REPORTED DATA(lt_reported_modify). 
   
   ENDMETHOD.
   

3. Your class will look like the following:

   

4. Now implement the additional save method to raise the entity event.

   save

   Copy

   METHOD save_modified.
   
   IF create-online_shop IS NOT INITIAL.
     RAISE ENTITY EVENT ZI_online_shop_###~ItemIsOrdered
   FROM VALUE #( FOR online_shop IN create-online_shop ( %key              = online_shop-%key
                                                         %param-ItemName   = online_shop-Ordereditem ) ).
   ENDIF.
   ENDMETHOD.
   

5. Save and activate your class.

   

1. Right-click on your data definition ZC_ONLINE_SHOP_### and select New Behavior Definition.

   

2. Save and activate the definition.

   

At last, you need to define the service definition and the service binding. Then your application will be ready to use.

1. Right-click on Business Services > New > Service Definition.

   • Name: ZUI_ONLINE_SHOP_###
   • Description: service definition for online shop
   
   

   Click Next and after choosing a transport request click Finish.

2. Here you can expose your data definition zc_online_shop_###

   

3. Save and activate your service definition.

4. Right-click on your service definition and choose New Service Binding.

   • Name: ZUI_ONLINE_SHOP_###
   • Description: service Binding for online shop
   • Binding Type: OData V2 - UI
   • Service Definition: ZUI_ONLINE_SHOP_###
   
   

5. Activate your service binding and click Publish.

   

Now create the event binding for your newly created business event. This event binding is needed to map an event to a RAP entity event.

1. Right-click on your package and create an event binding

   • Name: ZEVENT_EXPOSURE_###
   • Description: RAP business event
   
   

2. Here fill all fields out, to get errors gone. You can freely choose these names to specify your event with some considerations explained below

   • Namespace: zevent### (No camel case and no space)
   • Business Object: OnlineShop (No Space)
   • Business Object Operation: create
   

3. Click Add to add items.

   • Root Entity Name: ZI_ONLINE_SHOP_### (your behavior definition)
   • Entity Event Name: ITEMISORDERED (Event name in your behavior definition)
   

4. Save and activate your event binding.

5. As you can see at the screenshot, Type (aka topic) is a concatenation of the three attributes (name space, business object, business object operation) and ends with the version of the event. The wildcard * points to the corresponding event e.g. created. This is relevant for addressing the events to the Event Mesh. Copy this address for later use zevent###.OnlineShop.create.v*.

   

After an event is raised, it should arrive at the Event Mesh to be consumed later. The connection between the system and the SAP Event Mesh is achieved through a channel. For this, you need to create a communication arrangement in your cloud system with sap_com_0092 scenario which is built for an event enablement and also an event mesh instance’s service key.

One requirement is that you have an existing SAP Event Mesh service instance of the default plan. You can create an instance of SAP Event Mesh provided that you already subscribe to the event mesh service.

For more information about how to create instance of SAP Event Mesh link

1. Log on to your cloud system and navigate to communication Arrangement.

   

2. Click New to create a new communication arrangement.

   
   

3. Choose sap_com_0092 as Scenario and copy the service key of your event mesh instance under Service Key.

   
   

4. Create a Communication User. Click New and enter a User Name, Description and Propose Password. Copy the generated password and save it for later. Click Create.

   
   

5. Now change the Arrangement Name to Z_EVT_0092_### and replace ### with your initials or group number. This Arrangement Name will also be the name of the channel which is used later to send events.

   Click Create communication arrangement.

   

6. Open your newly created communication arrangement and check the connection under Outbound Services.

   
   

1. Search for Enterprise Event Enablement App and open it.

   

2. Click Go to open a list of channels and choose your channel in this list.

   

3. Now add the outbound topic, which is generated during the event binding generation, in to this channel:

   Click Create

   

   On the next page click Topic value help

   

   In this popup search for zevent###/OnlineShop/create/* what you copied in step 8-5 and choose it. Replace ### with your number.

   

   Click Create

   
   

4. In your channel scroll down to Event Metadata and copy the channels data for later use.

   

   If the metadata is empty please reload the page with F5 and try again.

5. Open your cloud system cockpit and navigate to Instances and Subscriptions and open your SAP event mesh service.

   

6. Open the message client, navigate to Queues and click Create Queue.

   
   

7. Enter a queue name and click Create.

   • Queue Name: onlineshop/### (replace ### with your number)

   

8. Open Actions of your newly created queue and click Queue Subscriptions. Here enter the topic what you copied from the event metadata and click Add and then Close the popup.

   
   
   

1. Open ADT and open your SAP BTP ABAP environment system.

2. Navigate to your service binding ZUI_ONLINE_SHOP_### and click Preview to open your application.

   

3. Click Create to order a new item.

   
   
   

4. Back to your cockpit and check in your event mesh under Queues if this event has reached the system. If you check the queue, a new message is arrived at the queue.

   

5. Navigate to Test and choose your queue under Queue.

   

6. Click Consume Message to consume this event in your applications. Here you can see that you have the type which you have find in the event binding and the transported data is the parameter structure.

   

You can also consume this event using Event Consumption Model within a Business Application