RAP Feature Control: Dynamically Control UI Elements

Static vs. Dynamic Feature Control

RAP distinguishes between static (declarative) and dynamic (programmatic) Feature Control:

Aspect	Static Feature Control	Dynamic Feature Control
Definition	In Behavior Definition	In Behavior Implementation
Evaluation	Compile time	Runtime
Context	Always the same	Instance or global dependent
Example	`field ( readonly ) TravelId`	`features: instance`

Static Feature Control

Static features are declared directly in the Behavior Definition:

define behavior for ZI_Travel alias Travel
persistent table ztravel
lock master
authorization master ( instance )
etag master LastChangedAt
{
  create;
  update;
  delete;

  // Static field features
  field ( readonly ) TravelId;                    " Always read-only
  field ( mandatory ) CustomerId;                 " Always mandatory
  field ( readonly : update ) AgencyId;           " Read-only only on update
  field ( readonly ) CreatedBy, CreatedAt;        " Admin fields
}

Dynamic Feature Control

Dynamic features are calculated at runtime:

define behavior for ZI_Travel alias Travel
{
  // Operations with dynamic feature control
  delete ( features: instance );

  // Fields with dynamic feature control
  field ( features: instance ) Status, Description;

  // Actions with dynamic feature control
  action ( features: instance ) acceptTravel result [1] $self;
  action ( features: instance ) rejectTravel result [1] $self;

  // Enable global feature control
  static features;
}

Instance Feature Control

Instance Feature Control enables controlling features per instance based on their data state.

Implementation

CLASS lhc_travel DEFINITION INHERITING FROM cl_abap_behavior_handler.
  PRIVATE SECTION.
    METHODS get_instance_features FOR INSTANCE FEATURES
      IMPORTING keys REQUEST requested_features FOR Travel
      RESULT result.
ENDCLASS.

CLASS lhc_travel IMPLEMENTATION.
  METHOD get_instance_features.
    " Read current instance data
    READ ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        FIELDS ( Status )
        WITH CORRESPONDING #( keys )
      RESULT DATA(lt_travel)
      FAILED failed.

    " Set features per instance
    result = VALUE #( FOR ls_travel IN lt_travel
      LET lv_is_open = xsdbool( ls_travel-Status = 'O' )
          lv_is_accepted = xsdbool( ls_travel-Status = 'A' )
      IN (
        %tky = ls_travel-%tky

        " Delete only allowed for status 'Open'
        %delete = COND #(
          WHEN lv_is_open = abap_true
          THEN if_abap_behv=>fc-o-enabled
          ELSE if_abap_behv=>fc-o-disabled
        )

        " Fields read-only or editable based on status
        %field-Status = COND #(
          WHEN lv_is_open = abap_true
          THEN if_abap_behv=>fc-f-unrestricted
          ELSE if_abap_behv=>fc-f-read_only
        )
        %field-Description = COND #(
          WHEN lv_is_open = abap_true
          THEN if_abap_behv=>fc-f-unrestricted
          ELSE if_abap_behv=>fc-f-read_only
        )

        " Accept action only for status 'Open'
        %action-acceptTravel = COND #(
          WHEN lv_is_open = abap_true
          THEN if_abap_behv=>fc-o-enabled
          ELSE if_abap_behv=>fc-o-disabled
        )

        " Reject action only for status 'Accepted'
        %action-rejectTravel = COND #(
          WHEN lv_is_accepted = abap_true
          THEN if_abap_behv=>fc-o-enabled
          ELSE if_abap_behv=>fc-o-disabled
        )
      )
    ).
  ENDMETHOD.
ENDCLASS.

Feature Constants

Constant	Type	Description
`if_abap_behv=>fc-o-enabled`	Operation	Operation enabled
`if_abap_behv=>fc-o-disabled`	Operation	Operation disabled
`if_abap_behv=>fc-f-read_only`	Field	Read-only
`if_abap_behv=>fc-f-mandatory`	Field	Mandatory
`if_abap_behv=>fc-f-unrestricted`	Field	No restriction
`if_abap_behv=>fc-f-mandatory_and_read_only`	Field	Mandatory and read-only

Global Feature Control

Global Feature Control controls features independent of individual instances - typically based on authorizations or system states.

Behavior Definition

define behavior for ZI_Travel alias Travel
{
  // Create with global feature control
  create ( features: global );

  // Static actions with global feature control
  static action ( features: global ) massUpdate;
  static action ( features: global ) importData;

  // Enable global features
  static features;
}

Implementation

CLASS lhc_travel DEFINITION INHERITING FROM cl_abap_behavior_handler.
  PRIVATE SECTION.
    METHODS get_global_features FOR GLOBAL FEATURES
      IMPORTING REQUEST requested_features FOR Travel
      RESULT result.
ENDCLASS.

CLASS lhc_travel IMPLEMENTATION.
  METHOD get_global_features.
    " Authorization check
    AUTHORITY-CHECK OBJECT 'Z_TRAVEL'
      ID 'ACTVT' FIELD '01'.  " Create
    DATA(lv_has_create_auth) = xsdbool( sy-subrc = 0 ).

    AUTHORITY-CHECK OBJECT 'Z_TRAVEL'
      ID 'ACTVT' FIELD '02'.  " Change
    DATA(lv_has_change_auth) = xsdbool( sy-subrc = 0 ).

    result = VALUE #(
      " Create only with authorization
      %create = COND #(
        WHEN lv_has_create_auth = abap_true
        THEN if_abap_behv=>fc-o-enabled
        ELSE if_abap_behv=>fc-o-disabled
      )

      " massUpdate only with change authorization
      %action-massUpdate = COND #(
        WHEN lv_has_change_auth = abap_true
        THEN if_abap_behv=>fc-o-enabled
        ELSE if_abap_behv=>fc-o-disabled
      )
    ).
  ENDMETHOD.
ENDCLASS.

Features for Standard Operations

Create, Update, Delete

define behavior for ZI_Travel alias Travel
{
  // Static feature control
  create;                              " Always allowed
  update;                              " Always allowed
  delete ( features: instance );       " Dynamic per instance
}

METHOD get_instance_features.
  READ ENTITIES OF zi_travel IN LOCAL MODE
    ENTITY Travel
      FIELDS ( Status )
      WITH CORRESPONDING #( keys )
    RESULT DATA(lt_travel).

  result = VALUE #( FOR ls_travel IN lt_travel (
    %tky = ls_travel-%tky

    " Update only for status Open or Draft
    %update = COND #(
      WHEN ls_travel-Status = 'O' OR ls_travel-Status = 'D'
      THEN if_abap_behv=>fc-o-enabled
      ELSE if_abap_behv=>fc-o-disabled
    )

    " Delete only for status Open
    %delete = COND #(
      WHEN ls_travel-Status = 'O'
      THEN if_abap_behv=>fc-o-enabled
      ELSE if_abap_behv=>fc-o-disabled
    )
  ) ).
ENDMETHOD.

Interaction with Authorization

Feature Control and Authorization complement each other:

Authorization: Permission check - returns error on unauthorized access
Feature Control: UI control - prevents users from seeing disallowed actions

CLASS lhc_travel DEFINITION INHERITING FROM cl_abap_behavior_handler.
  PRIVATE SECTION.
    METHODS get_instance_authorizations FOR INSTANCE AUTHORIZATION
      IMPORTING keys REQUEST requested_authorizations FOR Travel
      RESULT result.

    METHODS get_instance_features FOR INSTANCE FEATURES
      IMPORTING keys REQUEST requested_features FOR Travel
      RESULT result.
ENDCLASS.

CLASS lhc_travel IMPLEMENTATION.
  METHOD get_instance_authorizations.
    " Authorization check
    READ ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        FIELDS ( AgencyId )
        WITH CORRESPONDING #( keys )
      RESULT DATA(lt_travel).

    LOOP AT lt_travel INTO DATA(ls_travel).
      " Check authorization for this agency
      AUTHORITY-CHECK OBJECT 'Z_AGENCY'
        ID 'AGENCY' FIELD ls_travel-AgencyId
        ID 'ACTVT'  FIELD '02'.

      DATA(lv_authorized) = xsdbool( sy-subrc = 0 ).

      APPEND VALUE #(
        %tky = ls_travel-%tky
        %update = COND #( WHEN lv_authorized = abap_true
                          THEN if_abap_behv=>auth-allowed
                          ELSE if_abap_behv=>auth-unauthorized )
        %delete = COND #( WHEN lv_authorized = abap_true
                          THEN if_abap_behv=>auth-allowed
                          ELSE if_abap_behv=>auth-unauthorized )
      ) TO result.
    ENDLOOP.
  ENDMETHOD.

  METHOD get_instance_features.
    " Feature Control: Based on status AND authorization
    READ ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        FIELDS ( Status AgencyId )
        WITH CORRESPONDING #( keys )
      RESULT DATA(lt_travel).

    LOOP AT lt_travel INTO DATA(ls_travel).
      " Check authorization
      AUTHORITY-CHECK OBJECT 'Z_AGENCY'
        ID 'AGENCY' FIELD ls_travel-AgencyId
        ID 'ACTVT'  FIELD '02'.
      DATA(lv_has_auth) = xsdbool( sy-subrc = 0 ).

      " Combination: Status Open AND authorization
      DATA(lv_can_edit) = xsdbool( ls_travel-Status = 'O' AND lv_has_auth = abap_true ).

      APPEND VALUE #(
        %tky = ls_travel-%tky
        %delete = COND #( WHEN lv_can_edit = abap_true
                          THEN if_abap_behv=>fc-o-enabled
                          ELSE if_abap_behv=>fc-o-disabled )
        %field-Description = COND #( WHEN lv_can_edit = abap_true
                                     THEN if_abap_behv=>fc-f-unrestricted
                                     ELSE if_abap_behv=>fc-f-read_only )
      ) TO result.
    ENDLOOP.
  ENDMETHOD.
ENDCLASS.

Dynamically Set Mandatory Fields

METHOD get_instance_features.
  READ ENTITIES OF zi_travel IN LOCAL MODE
    ENTITY Travel
      FIELDS ( Status TravelType )
      WITH CORRESPONDING #( keys )
    RESULT DATA(lt_travel).

  result = VALUE #( FOR ls_travel IN lt_travel (
    %tky = ls_travel-%tky

    " CustomerID is mandatory for business trips
    %field-CustomerId = COND #(
      WHEN ls_travel-TravelType = 'B'  " Business
      THEN if_abap_behv=>fc-f-mandatory
      ELSE if_abap_behv=>fc-f-unrestricted
    )

    " Approval is mandatory above certain amount
    %field-ApproverId = COND #(
      WHEN ls_travel-TotalPrice > 5000
      THEN if_abap_behv=>fc-f-mandatory
      ELSE if_abap_behv=>fc-f-unrestricted
    )
  ) ).
ENDMETHOD.

Performance Optimization

Feature Control is called frequently. Optimize the implementation:

METHOD get_instance_features.
  " 1. Only calculate needed features
  CHECK requested_features-%delete = if_abap_behv=>mk-on
     OR requested_features-%action-acceptTravel = if_abap_behv=>mk-on
     OR requested_features-%field-Status = if_abap_behv=>mk-on.

  " 2. Read minimal fields
  READ ENTITIES OF zi_travel IN LOCAL MODE
    ENTITY Travel
      FIELDS ( Status )  " Only what's needed
      WITH CORRESPONDING #( keys )
    RESULT DATA(lt_travel).

  " 3. Efficient loop
  result = VALUE #( FOR ls_travel IN lt_travel (
    %tky = ls_travel-%tky
    %delete = COND #( WHEN ls_travel-Status = 'O'
                      THEN if_abap_behv=>fc-o-enabled
                      ELSE if_abap_behv=>fc-o-disabled )
    " ... more features
  ) ).
ENDMETHOD.

Best Practices

Consistency: Feature Control and validations must be consistent - a disabled field should not be checked in a validation
IN LOCAL MODE: Use IN LOCAL MODE to avoid authorization loops
Minimal database access: Only read fields needed for the feature decision
Global vs. Instance: Use Global Feature Control for authorization-based features, Instance for data-based
Check requested features: Only calculate requested features for performance optimization
Documentation: Document the feature logic so other developers understand why fields/actions are available when

RAP Feature Control: Dynamically Control UI Elements

Static vs. Dynamic Feature Control

Static Feature Control

Dynamic Feature Control

Instance Feature Control

Implementation

Feature Constants

Global Feature Control

Behavior Definition

Implementation

Features for Standard Operations

Create, Update, Delete

Interaction with Authorization

Dynamically Set Mandatory Fields

Performance Optimization

Best Practices

Further Reading