unit3.md

HANDS-ON EXERCISE FOR WEEK 3 UNIT 3: CREATING THE BUSINESS OBJECT BEHAVIOR PROJECTION

Previous exercise:

Week 3 Unit 2: Defining the Basic Business Object Behavior

Introduction

In the present hands-on exercise, you will project the transactional capabilities that we want to enable in our app by creating the business object behavior projection and test your enhanced Travel app.

You can watch week 3 unit 3: Creating the Business Object Behavior Projection on the openSAP platform.

Hints and Tips
Speed up the typing by making use of the Code Completion feature (shortcut Ctrl+Space) and the prepared code snippets provided. You can easily open an object with the shortcut Ctrl+Shift+A, format your source code using the Pretty Printer feature Shift+F1 and toggle the fullscreen of the editor using the shortcut Ctrl+M.

A great overview of ADT shortcuts can be found here: Useful ADT Shortcuts

Please note that the placeholder #### used in object names in the exercise description must be replaced with the suffix of your choice during the exercises. The suffix can contain a maximum of 4 characters (numbers and letters). The screenshots in this document have been taken with the suffix 1234 and system D20. Your system id will be TRL.

Please note that the ADT dialogs and views may change in the future due to software updates.

Follow the instructions below.

Step 1. Create the BO Behavior Projection

Now you will create the behavior projection ZC_RAP_TRAVEL_#### (where #### is your chosen suffix) for the projected composition model.

1. Right-click on the root CDS view ZC_RAP_TRAVEL_#### in the Project Explorer and choose New Behavior Definition.

   

2. The New Behavior Definition wizard is shown. The Name of the behavior definition has to be the identical name as the root CDS view. That’s the reason why the name can’t be changed.
   Adjust the proposed Description if you like, ensure that the Implementation Type is set to Projection and choose Next > to continue.
   Project, Package and Root Entity have been assigned automatically.

   

3. Assign a transport request and choose Finish.

   

   A skeleton for the new behavior projection for all entities – i.e. the travel entity ZC_RAP_Travel_#### and the booking entity ZC_RAP_Booking_#### in the present scenario – is generated based on the chosen implementation and displayed in the appropriate editor.

   

   Short explanation:

   • projection is specified at the top since the proper implementation type is specified in the underlying behavior definition.
   • All operations and associations defined in the underlying behavior definition at the creation time are automatically exposed in the projection using the keyword use.

Step 2. Adjust the BO Behavior Projection

Now, you will adjust the behavior projection.

1. First, define an alias for the travel and the booking entity in the define behavior for statement. Use the commented statement alias <alias_name> for that.
   For the travel entity:

   alias Travel

   For the booking entity:

   alias Booking

2. Enable the optimistic lock – i.e. the ETag handling – for both entities.
   For that, add the statement below after define behavior for statement line.

   use etag

3. Recap of the adjustments
   Your behavior projection will look as follows.

   

   Below is the corresponding code snippet, where #### to be replaced with your chosen suffix.

   projection;
   
   define behavior for ZC_RAP_Travel_#### alias Travel
   use etag
   {
      use create;
      use update;
      use delete;
   
      use association _Booking { create; }
    }
   
   define behavior for ZC_RAP_Booking_#### alias Booking
   use etag
   {
     use update;
     use delete;
   
     use association _Travel;
   }
   

4. Save and activate the behavior projection.

Step 3. Preview the Travel App & Play around

1. Start the Travel app in your service binding ZUI_RAP_TRAVEL_O2_#### (where #### is your chosen suffix) or refresh (F5) it in the browser. Provide your ABAP user credentials if requested.
   In the trial environment it might take a while until your changes are reflected.

   As a result, you can see that now, the create, update and delete operations are enabled.
   Press Go on the UI to load the back-end data.

   

   Object Page:
   

2. Feel free to play around with your application – e.g. create, delete or update/edit travel and booking entities.
   The Edit button is always available on the relevant Object Page.

Summary

You have completed the exercise!
In this unit, you have learned how to create the behavior projection for our managed Travel business object, projecting the behavior for the travel and booking entities.

Solution

You can find the source code of the created CDS behavior projection in the sources folder:

• W3U3_BDEF_ZC_RAP_TRAVEL_####

Do not forget to replace all the occurrences of #### with your chosen suffix in the copied source code.

Next exercise

Week 3 Unit 4: Understanding Entity Manipulation Language (EML)