Enhance Behavior With Action and Validation

Switch to your behavior definition ZI_TRAVEL_M_XXX and add following action and validation to your coding:

// instance action and dynamic action control
action  ( features: instance ) acceptTravel result [1] $self;

// validations
validation validateCustomer on save { field customer_id; }
validation validateDates    on save { field begin_date, end_date; }
validation validateStatus   on save { field overall_status; }

Your result should look like this. Replace your code with following:

managed implementation in class ZCL_BP_I_TRAVEL_M_XXX unique;

define behavior for ZI_Travel_M_XXX alias Travel
persistent table ztravel_xxx
etag last_changed_at
lock master
{
// administrative fields (read only)
field ( readonly ) last_changed_at, last_changed_by, created_at, created_by;

// mandatory fields that are required to create a travel
field ( mandatory ) agency_id, overall_status, booking_fee, currency_code;

// dynamic field control
field (features : instance ) travel_id;

// standard operations for travel entity
create;
update;
delete;

// instance action and dynamic action control
action  ( features: instance ) acceptTravel result [1] $self;

// validations
validation validateCustomer on save { field customer_id; }
validation validateDates    on save { field begin_date, end_date; }
validation validateStatus   on save { field overall_status; }
}

Ignore the warning, save and activate.

Open your behavior implementation ZCL_BP_I_TRAVEL_M_XXX and switch to local types to replace your code.

In your local types replace your code with following:

*"* use this source file for the definition and implementation of
*"* local helper classes, interface definitions and type
*"* declarations
CLASS lhc_travel DEFINITION INHERITING FROM cl_abap_behavior_handler.

PRIVATE SECTION.

TYPES tt_travel_update TYPE TABLE FOR UPDATE zi_travel_m_xxx.

METHODS validate_customer          FOR VALIDATION travel~validateCustomer IMPORTING keys FOR travel.
METHODS validate_dates             FOR VALIDATION travel~validateDates    IMPORTING keys FOR travel.
METHODS validate_travel_status     FOR VALIDATION travel~validateStatus   IMPORTING keys FOR travel.

METHODS set_status_completed       FOR MODIFY IMPORTING   keys FOR ACTION travel~acceptTravel              RESULT result.
METHODS get_features               FOR FEATURES IMPORTING keys REQUEST    requested_features FOR travel    RESULT result.

ENDCLASS.

CLASS lhc_travel IMPLEMENTATION.

**********************************************************************
*
* Validate customer data when saving travel data
*
**********************************************************************
METHOD validate_customer.

READ ENTITY zi_travel_m_xxx\\travel FROM VALUE #(
    FOR <root_key> IN keys ( %key     = <root_key>
                             %control = VALUE #( customer_id = if_abap_behv=>mk-on ) ) )
    RESULT DATA(lt_travel).

DATA lt_customer TYPE SORTED TABLE OF /dmo/customer WITH UNIQUE KEY customer_id.

" Optimization of DB select: extract distinct non-initial customer IDs
lt_customer = CORRESPONDING #( lt_travel DISCARDING DUPLICATES MAPPING customer_id = customer_id EXCEPT * ).
DELETE lt_customer WHERE customer_id IS INITIAL.
CHECK lt_customer IS NOT INITIAL.

" Check if customer ID exist
SELECT FROM /dmo/customer FIELDS customer_id
  FOR ALL ENTRIES IN @lt_customer
  WHERE customer_id = @lt_customer-customer_id
  INTO TABLE @DATA(lt_customer_db).

" Raise msg for non existing customer id
LOOP AT lt_travel INTO DATA(ls_travel).
  IF ls_travel-customer_id IS NOT INITIAL AND NOT line_exists( lt_customer_db[ customer_id = ls_travel-customer_id ] ).
    APPEND VALUE #(  travel_id = ls_travel-travel_id ) TO failed.
    APPEND VALUE #(  travel_id = ls_travel-travel_id
                     %msg      = new_message( id       = /dmo/cx_flight_legacy=>customer_unkown-msgid
                                              number   = /dmo/cx_flight_legacy=>customer_unkown-msgno
                                              v1       = ls_travel-customer_id
                                              severity = if_abap_behv_message=>severity-error )
                     %element-customer_id = if_abap_behv=>mk-on ) TO reported.
  ENDIF.

ENDLOOP.

ENDMETHOD.


**********************************************************************
*
* Check validity of date
*
**********************************************************************
METHOD validate_dates.

READ ENTITY zi_travel_m_xxx\\travel FROM VALUE #(
    FOR <root_key> IN keys ( %key     = <root_key>
                             %control = VALUE #( begin_date = if_abap_behv=>mk-on
                                                 end_date   = if_abap_behv=>mk-on ) ) )
    RESULT DATA(lt_travel_result).

LOOP AT lt_travel_result INTO DATA(ls_travel_result).

  IF ls_travel_result-end_date < ls_travel_result-begin_date.  "end_date before begin_date

    APPEND VALUE #( %key        = ls_travel_result-%key
                    travel_id   = ls_travel_result-travel_id ) TO failed.

    APPEND VALUE #( %key     = ls_travel_result-%key
                    %msg     = new_message( id       = /dmo/cx_flight_legacy=>end_date_before_begin_date-msgid
                                            number   = /dmo/cx_flight_legacy=>end_date_before_begin_date-msgno
                                            v1       = ls_travel_result-begin_date
                                            v2       = ls_travel_result-end_date
                                            v3       = ls_travel_result-travel_id
                                            severity = if_abap_behv_message=>severity-error )
                    %element-begin_date = if_abap_behv=>mk-on
                    %element-end_date   = if_abap_behv=>mk-on ) TO reported.

  ELSEIF ls_travel_result-begin_date < cl_abap_context_info=>get_system_date( ).  "begin_date must be in the future

    APPEND VALUE #( %key        = ls_travel_result-%key
                    travel_id   = ls_travel_result-travel_id ) TO failed.

    APPEND VALUE #( %key = ls_travel_result-%key
                    %msg = new_message( id       = /dmo/cx_flight_legacy=>begin_date_before_system_date-msgid
                                        number   = /dmo/cx_flight_legacy=>begin_date_before_system_date-msgno
                                        severity = if_abap_behv_message=>severity-error )
                    %element-begin_date = if_abap_behv=>mk-on
                    %element-end_date   = if_abap_behv=>mk-on ) TO reported.
  ENDIF.

ENDLOOP.

ENDMETHOD.

**********************************************************************
*
* Validate travel status when saving travel data
*
**********************************************************************
METHOD validate_travel_status.

READ ENTITY zi_travel_m_xxx\\travel FROM VALUE #(
  FOR <root_key> IN keys ( %key     = <root_key>
                           %control = VALUE #( overall_status = if_abap_behv=>mk-on ) ) )
  RESULT DATA(lt_travel_result).

LOOP AT lt_travel_result INTO DATA(ls_travel_result).
  CASE ls_travel_result-overall_status.
    WHEN 'O'.  " Open
    WHEN 'X'.  " Cancelled or rejected
    WHEN 'A'.  " Accepted

    WHEN OTHERS.
      APPEND VALUE #( %key = ls_travel_result-%key ) TO failed.

      APPEND VALUE #( %key = ls_travel_result-%key
                      %msg = new_message( id       = /dmo/cx_flight_legacy=>status_is_not_valid-msgid
                                          number   = /dmo/cx_flight_legacy=>status_is_not_valid-msgno
                                          v1       = ls_travel_result-overall_status
                                          severity = if_abap_behv_message=>severity-error )
                      %element-overall_status = if_abap_behv=>mk-on ) TO reported.
  ENDCASE.

ENDLOOP.

ENDMETHOD.


********************************************************************************
*
* Implements travel action (in our case: for setting travel overall_status to completed)
*
********************************************************************************
METHOD set_status_completed.

" Modify in local mode: BO-related updates that are not relevant for authorization checks
MODIFY ENTITIES OF zi_travel_m_xxx IN LOCAL MODE
       ENTITY travel
          UPDATE FROM VALUE #( for key in keys ( travel_id = key-travel_id
                                                 overall_status = 'A' " Accepted
                                                 %control-overall_status = if_abap_behv=>mk-on ) )
       FAILED   failed
       REPORTED reported.

  " Read changed data for action result
  READ ENTITIES OF zi_travel_m_xxx IN LOCAL MODE
       ENTITY travel
       FROM VALUE #( for key in keys (  travel_id = key-travel_id
                                        %control = VALUE #(
                                          agency_id       = if_abap_behv=>mk-on
                                          customer_id     = if_abap_behv=>mk-on
                                          begin_date      = if_abap_behv=>mk-on
                                          end_date        = if_abap_behv=>mk-on
                                          booking_fee     = if_abap_behv=>mk-on
                                          total_price     = if_abap_behv=>mk-on
                                          currency_code   = if_abap_behv=>mk-on
                                          overall_status  = if_abap_behv=>mk-on
                                          description     = if_abap_behv=>mk-on
                                          created_by      = if_abap_behv=>mk-on
                                          created_at      = if_abap_behv=>mk-on
                                          last_changed_by = if_abap_behv=>mk-on
                                          last_changed_at = if_abap_behv=>mk-on
                                        ) ) )
       RESULT DATA(lt_travel).

  result = VALUE #( for travel in lt_travel ( travel_id = travel-travel_id
                                              %param    = travel
                                            ) ).

ENDMETHOD.

********************************************************************************
*
* Implements the dynamic feature handling for travel instances
*
********************************************************************************
METHOD get_features.

READ ENTITY zi_travel_m_xxx FROM VALUE #( FOR keyval IN keys
                                                  (  %key                    = keyval-%key
                                                     %control-travel_id      = if_abap_behv=>mk-on
                                                     %control-overall_status = if_abap_behv=>mk-on ) )
                            RESULT DATA(lt_travel_result).


result = VALUE #( FOR ls_travel IN lt_travel_result
                   ( %key                           = ls_travel-%key
                     %features-%action-acceptTravel = COND #( WHEN ls_travel-overall_status = 'A'
                                                                THEN if_abap_behv=>fc-o-disabled ELSE if_abap_behv=>fc-o-enabled   )
                  ) ).

ENDMETHOD.


ENDCLASS.

Save and activate.

Switch to your behavior definition ZC_TRAVEL_M_XXX and add following action to your coding:

use action acceptTravel;

Your result should look like this. Replace your code with following:

projection;

define behavior for ZC_TRAVEL_M_XXX alias TravelProcessor
use etag
{
// scenario specific field control
field ( mandatory ) BeginDate, EndDate, CustomerID;

use create;
use update;
use delete;

use action acceptTravel;
}

ignore the warning, save and activate.

The validation allows you to check the data consistency of your travel booking application.

By using actions your are able to change the status of your booking status.

Now switch to your service binding and double click on TravelProcessor.

Check your result.

The accept travel button appears, but this can take a few minutes.
Create a new travel booking with the booking status O.
O stands for open. Save your travel booking and you are able to accept your created travel booking.