Error situations

• Service not updated after a change => bump the binding version or recreate the binding
• Associated view not visible => expose the view in the Service Definition
• No browser permission shown before login => try a different browser (e.g., Chrome)
• Navigation from a user/task list to a single task not shown or not possible => restarting the browser sometimes helps

Draft — key facts

• Definition: Draft handling in RAP allows users to persist incomplete changes in a draft state without committing them to the main persistent data immediately.
• Goals:
  • Improve the user experience by allowing partial or interrupted edits to be saved.
  • Avoid inconsistent data states.
• Draft object: A persistent representation of the transactional buffer which stores the in-progress changes before they are finalized.
• Automatic locking behavior: Drafts are user-bound and prevent parallel editing of the same draft (status as of Nov 2024 — behavior may evolve).
• Separation of draft and persistence logic: Changes saved in the draft do not affect the main persistent object until finalization.

Projections

• Definition: Projections are specialized, consumption-oriented views on existing Business Objects in RAP. They allow tailoring the data model and behavior to the needs of a specific application or role.
• Goals:
  • Simplify data models for particular scenarios.
  • Separate backend logic from UI-specific requirements.
  • Reuse data models across different applications.

Feature Control

All properties in a Behavior Definition can be controlled dynamically, for example the availability of actions.

Declare a controlled action in the Behavior

Mark the action as feature-controlled in the behavior definition:

action (features: instance) cancel result [1] $self;

Implement dynamic decision in ABAP

The Behavior Handler returns the feature state (available / unavailable) during runtime. Example placeholder in ABAP:

METHOD get_features.

	" Implement feature decision logic here and fill the response

ENDMETHOD.

Virtual Elements — ABAP-calculated fields

Virtual elements are read-only fields whose values are computed in ABAP. They are useful when a value cannot be derived directly from a database column and must be calculated at runtime.

In the CDS view

@ObjectModel.virtualElement: true
@ObjectModel.virtualElementCalculatedBy: 'ABAP:ZCL_BC_VIRTUAL_ELE'
'' as VirtualFieldName,

In the ABAP class

Implement a class such as ZCL_BC_VIRTUAL_ELE and the required SADL/exit interfaces, e.g. IF_SADL_EXIT_CALC_ELEMENT_READ.

Optional: GET_CALCULATION_INFO before select

If the calculation requires additional fields, implement GET_CALCULATION_INFO to return the list of fields that need to be selected from the DB. These fields are then provided to your calculation logic.