Lesson 16 Practice — Expose the Support Issue BO with OData V4

Your Support Issue BO already has:

managed CRUD
EML
determinations
validations
messages
actions
feature control
authorization

Now expose it as a consumer-facing RAP business service.

Target architecture:

ZISSUE_###
    ↓
ZR_ISSUE_###
    ↓
ZC_ISSUE_###
    ↓
Projection BDEF
    ↓
ZUI_ISSUE_###
    ↓
ZUI_ISSUE_###_O4
    ↓
OData V4 UI
    ↓
Fiori Elements Preview

---

Practice information

Time	About 3 hours
Prerequisite	Lesson 16 teacher-led work
Base BO	ZR_ISSUE_###
Projection	ZC_ISSUE_###
Service Definition	ZUI_ISSUE_###
Service Binding	ZUI_ISSUE_###_O4
Protocol	OData V4 UI
Main goal	Expose the secured Issue BO without duplicating business logic

---

1. Verify the starting BO

Confirm these activate:

ZISSUE_###
ZR_ISSUE_###
base Access Control
Behavior Definition
ZBP_R_ISSUE_###

You should already have:

ResponsibleUser
DCL
global authorization
instance authorization
startProcessing action
close action
dynamic feature control

Do not start the service layer until the base BO works.

---

2. Objects to create

Create:

ZC_ISSUE_###
Access Control for ZC_ISSUE_###
Projection Behavior Definition for ZC_ISSUE_###
Metadata Extension for ZC_ISSUE_###
ZUI_ISSUE_###
ZUI_ISSUE_###_O4

Do not create:

new persistence table
new Behavior Pool
draft table
draft BDEF

---

3. Design the projection

The projection should expose these business fields:

Uuid
IssueNo
Title
Description
RequesterEmail
Priority
Status
ReportedOn
EstimatedCost
CurrencyCode
ResponsibleUser

Also expose the administrative fields required for service behavior/debugging.

---

4. Create ZC_ISSUE_###

Use:

define root view entity

and:

provider contract transactional_query

Project from:

ZR_ISSUE_###

---

5. Projection header requirements

Use:

@AccessControl.authorizationCheck: #CHECK
@Metadata.allowExtensions: true
@Search.searchable: true

Provide a useful end-user label.

---

6. Search fields

Make these default search elements:

IssueNo
Title

Do not mark every field as a default search field.

---

7. Currency value help

Add a value help to:

CurrencyCode

Use the same standard provider used in the guided Reservation lesson:

I_CurrencyStdVH

Map to:

Currency

Use the current @Consumption.valueHelpDefinition syntax.

---

8. Value help reasoning

Answer:

Does value help validate all business rules?

Does value help replace validateCost?

Why is value help a projection-layer concern?

---

9. Activate and preview the projection

Use:

Ctrl+F3
F8

At this moment, inspect whether the projection reveals only the data you expect.

Do not assume the base DCL automatically protects it.

---

10. Explain DCL propagation

Complete:

Base DCL protects:
____________________

Projection entity is:
____________________

Does CDS automatically inherit access controls?
____________________

The correct architectural answer must acknowledge that the projection needs its own access control.

---

11. Create projection Access Control

Create an Access Control object for:

ZC_ISSUE_###

Requirements:

@MappingRole: true
grant select on ZC_ISSUE_###
inherit conditions from ZR_ISSUE_###

Do not manually duplicate the ResponsibleUser condition.

---

12. Required DCL source shape

Your DCL should be equivalent to:

@EndUserText.label: 'Issue Projection Access'
@MappingRole: true
define role ZC_Issue_###
{
  grant select on ZC_Issue_###
    where inheriting conditions from entity ZR_Issue_###;
}

Use the exact names from your objects.

---

13. Re-test projection Data Preview

After activating the projection DCL:

F8

Expected:

the projection respects the same read authorization
as the base Issue entity

If you intentionally still have an unassigned Issue, it must not reappear through the projection.

---

14. Create projection BDEF

Right-click:

ZC_ISSUE_###

Create a Behavior Definition with:

Implementation Type: Projection

---

15. Projection BDEF header

Use:

projection;
strict ( 2 );

Do not create:

managed implementation
unmanaged implementation
new behavior pool

---

16. Reuse ETag

If your base Issue BO uses:

LocalLastChangedAt

as ETag master, reuse ETag behavior in the projection.

Required concept:

use etag

---

17. Reuse standard operations

Expose:

create
update
delete

with projection behavior syntax.

Remember:

use create
use update
use delete

does not reimplement CRUD.

---

18. Reuse actions

Expose:

startProcessing
close

through the projection BDEF.

Do not copy action implementation into a new class.

---

19. Projection BDEF target

Your final behavior should be equivalent to:

projection;
strict ( 2 );

define behavior for ZC_Issue_### alias Issue
use etag
{
  use create;
  use update;
  use delete;

  use action startProcessing;
  use action close;
}

Adjust names to your actual entity/alias.

---

20. Explain reused behavior

For each item, state where the implementation still lives:

create:
____________________

validateTitle:
____________________

setInitialStatus:
____________________

startProcessing:
____________________

instance authorization:
____________________

feature control:
____________________

A correct answer should point back to the base RAP BO / Behavior Pool, not the projection.

---

21. Create metadata extension

Enable metadata extensions in the projection.

Then create a Metadata Extension for:

ZC_ISSUE_###

Use:

@Metadata.layer: #CORE

---

22. Header information

Configure:

typeName       = Issue
typeNamePlural = Issues
title field    = IssueNo

Use:

@UI.headerInfo

Also add an identification-reference facet so the object page has a clear main section.

---

23. List-report fields

Add @UI.lineItem annotations for:

IssueNo
Title
Priority
Status
ReportedOn
EstimatedCost
CurrencyCode
ResponsibleUser

Choose sensible positions.

---

24. Object-page fields

Add @UI.identification for at least:

IssueNo
Title
Description
RequesterEmail
Priority
Status
ReportedOn
EstimatedCost
CurrencyCode
ResponsibleUser

---

25. Selection fields

Use @UI.selectionField for:

Priority
Status
ReportedOn
CurrencyCode

Do not make every field a filter.

---

25A. Expose action buttons in UI metadata

Add Fiori Elements action records for:

startProcessing
close

Use:

type: #FOR_ACTION

and the correct:

dataAction

inside both:

@UI.lineItem
@UI.identification

You may attach the annotations to the Status element.

The action names must match the names exposed by the projection BDEF.

---

26. Metadata separation reasoning

Explain why:

@UI.lineItem

belongs in the metadata extension but:

validateTitle

does not.

---

27. Create Service Definition

Create:

ZUI_ISSUE_###

Expose:

ZC_ISSUE_###
I_CurrencyStdVH

Use service aliases.

Recommended aliases:

Issues
Currencies

---

28. Service Definition source target

Equivalent source:

@EndUserText.label: 'Issue UI Service'
define service ZUI_ISSUE_###
{
  expose ZC_Issue_###    as Issues;
  expose I_CurrencyStdVH as Currencies;
}

Activate it.

---

29. Explain why Currencies is exposed

Your answer must mention:

value-help provider
OData service
CurrencyCode

---

30. Create Service Binding

Create:

ZUI_ISSUE_###_O4

Use:

Service Definition:
ZUI_ISSUE_###

Binding:
OData V4 UI

Activate it.

---

31. Publish

Open the Service Binding editor.

Publish the service locally.

Record:

Published:
Yes / No

Do not confuse publishing with productive launchpad deployment.

---

32. Inspect service entities

The binding should contain entities equivalent to:

Issues
Currencies

If the value-help entity is missing, repair the Service Definition.

---

33. Launch Fiori Elements Preview

Select:

Issues

Launch Preview.

The generated UI should use the metadata extension.

---

34. Verify list columns

Record whether these are visible:

IssueNo
Title
Priority
Status
ReportedOn
EstimatedCost
CurrencyCode
ResponsibleUser

Repair metadata rather than changing the base persistence model.

---

35. Verify search

Use search with:

IssueNo
or
Title

Record one successful search.

---

36. Verify selection fields

Check the filter area for:

Priority
Status
ReportedOn
CurrencyCode

Record any differences caused by the current preview/UI layout.

---

37. Verify Currency value help

Open the value help for:

CurrencyCode

Confirm that a currency list is available.

Record one selected currency.

---

38. Verify DCL through service

The UI service must not reveal Issues that the current user is not authorized to read.

Explain which artifact protects:

ZC_ISSUE_###

from accidentally reopening read access.

---

39. Verify state-based action behavior

Use an owned:

Status = O

Issue.

Expected:

startProcessing available
close unavailable

Execute:

startProcessing

and verify:

Status = I

---

40. Re-check actions after state change

For:

Status = I

expected:

startProcessing unavailable
close available

This behavior should come from:

base feature control

not new UI code.

---

41. Execute close

Run:

close

Expected:

I → C

Verify final Status through the preview or a protected CDS read.

---

42. Verify dynamic field control

For:

Status = C

the cost fields should reflect Lesson 14 behavior:

EstimatedCost read-only
CurrencyCode read-only

Explain why no new projection handler was required.

---

43. Verify backend validation

Attempt an invalid create/update through the service.

Examples:

blank Title
future ReportedOn
negative EstimatedCost

Expected:

backend validation prevents invalid save
useful RAP message returned

---

44. Verify authorization

Use only an Issue whose:

ResponsibleUser = current user

for successful updates/actions.

Explain what should happen if:

state allows action
but current user is not authorized

---

45. Repair exercise — remove provider contract

Temporarily reason about omitting:

provider contract transactional_query

Restore it.

Explain why current projection modeling should specify its provider contract explicitly.

---

46. Repair exercise — remove root

Temporarily change:

define root view entity

to:

define view entity

Restore the correct root projection.

Explain the BO role lost by the incorrect declaration.

---

47. Repair exercise — omit projection action

Remove:

use action close

temporarily.

Activate and inspect the service behavior.

Restore it.

Explain:

base action exists
but service projection decides whether it is exposed

---

48. Repair exercise — remove projection DCL

Do not leave the system in this state.

Reason about what could happen if:

ZC_ISSUE_###

has no access control while only:

ZR_ISSUE_###

is protected.

Restore the projection DCL.

---

49. Repair exercise — omit value-help provider

Remove:

Currencies

from the Service Definition temporarily.

Inspect/consider the value-help result.

Restore it.

---

50. Repair exercise — put validation in metadata

Explain why this is architecturally wrong:

"Title is required"
implemented only as UI metadata

Where does the authoritative rule belong?

---

51. Repair exercise — Service Definition vs Binding

Complete:

If I need to add another CDS entity:
I change ______________________

If I need a different protocol:
I create/change ______________________

---

52. Certification-style mini task

Create a second projection for a hypothetical read-focused Issue service.

Requirements:

new projection CDS
subset of fields
transactional_query provider contract
projection DCL protection
projection BDEF that exposes no delete
separate Service Definition

You do not need to publish it if time is limited.

Explain how this proves that projections are service-specific.

---

53. Certification-style repair map

Complete:

Problem	First artifact to inspect
Action missing from service
Unauthorized row appears
Currency value help missing
Wrong list column order
Search does not use Title
OData endpoint missing
Validation accepts bad Title

---

54. Submission checklist

• ZC_ISSUE_### created.
• Projection remains root.
• transactional_query provider contract present.
• Projection uses #CHECK.
• Metadata extensions allowed.
• Search enabled.
• IssueNo default searchable.
• Title default searchable.
• Currency value help defined.
• Projection Access Control created.
• Projection DCL inherits base conditions.
• Projection Data Preview respects DCL.
• Projection BDEF created.
• Projection BDEF uses projection;.
• Projection BDEF uses strict ( 2 ).
• ETag reused.
• Create exposed.
• Update exposed.
• Delete exposed.
• startProcessing exposed.
• close exposed.
• Metadata extension created.
• Header info created.
• Line items created.
• Identification fields created.
• Selection fields created.
• Object-page identification facet created.
• startProcessing action button metadata added.
• close action button metadata added.
• ZUI_ISSUE_### created.
• Issues exposed.
• Currency provider exposed.
• ZUI_ISSUE_###_O4 created.
• OData V4 UI selected.
• Binding activated.
• Service published.
• Preview opens.
• Search verified.
• Currency value help verified.
• DCL verified through projection/service.
• State-driven actions verified.
• Dynamic field control verified.
• Validation message verified.
• Authorization behavior preserved.
• No draft artifacts added.

---

55. End-of-practice explanation

Explain without notes:

The base RAP BO contains reusable business behavior.

The projection defines the service-specific data surface.

The projection BDEF defines which base operations
the service exposes.

The projection needs its own read protection
because CDS DCL does not automatically propagate.

The metadata extension describes the UI.

The Service Definition chooses what is exposed.

The Service Binding chooses how it is exposed.

OData V4 carries the RAP BO to a UI consumer.

The service still uses the original validations,
actions, feature control, and authorization.

If you can build and explain that stack, you are ready for Lesson 17 Draft.