The problem - No support for functions and actions by the remote OData proxy client
A customer asked me how to use the remote OData proxy client in order to call a function import in their on premise SAP ERP from whithin their SAP BTP ABAP Environment.
This is unfortunately not possible using the remote OData proxy client since in Steampunk you can only create a remote OData proxy client based on a service conumption model which currently does not yet support function imports or actions.
As a result, code like the following will
NOT work in Steampunk:
data:
client_proxy TYPE REF TO /iwbep/if_cp_client_proxy,
function_resource type ref to /iwbep/if_cp_resource_function.
function_resource = client_proxy->create_resource_for_function( 'PROMOTE_EMPLOYEE')
With an upcoming update we plan to add a support for function imports and actions.
The solution - Use a http client
I thought about a workaround to overcome this technical restriction and came up with some ABAP sample code that shows how to use a http client based on the interface
In the following I am showing a sample that performs a POST request using the following URL:
https://sapes5.sapdevcenter.com/sap/opu/odata/IWBEP/GWSAMPLE_BASIC/SalesOrder_Confirm?sap-client='002'&SalesOrderID='0500010020'
Coding explained
The class contains a method
execute_action( ) that takes the name of the action and the parameter(s) as a list of name / value pairs.
This method first retrieves the
CSRF token which has to be sent in a http header when executing the POST request.
ABAP Code:
CLASS zact_test_call_action DEFINITION
PUBLIC
FINAL
CREATE PUBLIC .
PUBLIC SECTION.
INTERFACES if_oo_adt_classrun .
PROTECTED SECTION.
PRIVATE SECTION.
METHODS execute_action
IMPORTING i_action_name TYPE string
i_query_parameters TYPE if_web_http_request=>name_value_pairs OPTIONAL
RETURNING VALUE(response) TYPE string
RAISING cx_http_dest_provider_error
cx_web_http_client_error .
ENDCLASS.
CLASS zact_test_call_action IMPLEMENTATION.
METHOD if_oo_adt_classrun~main.
DATA query_parameters TYPE if_web_http_request=>name_value_pairs .
DATA action_name TYPE string.
query_parameters = VALUE #( ( name = 'SalesOrderID' value = '0500010020' ) ).
action_name = 'SalesOrder_Confirm'.
TRY.
DATA(response) = execute_action(
EXPORTING
i_action_name = action_name
i_query_parameters = query_parameters
).
out->write( |response: { response } | ).
CATCH cx_http_dest_provider_error INTO DATA(http_dest_provider_error).
"handle exception
out->write( http_dest_provider_error->get_longtext( ) ).
CATCH cx_web_http_client_error INTO DATA(web_http_client_error).
"handle exception
out->write( web_http_client_error->get_longtext( ) ).
ENDTRY.
ENDMETHOD.
METHOD execute_action.
DATA(demo_mode) = abap_false.
DATA http_header_fields TYPE if_web_http_request=>name_value_pairs .
http_header_fields = VALUE #( ( name = if_web_http_header=>accept value = |application/json| )
( name = if_web_http_header=>content_type value = |application/json| )
( name = 'x-csrf-token' value = 'fetch' ) ).
DATA(service_relative_url) = '/sap/opu/odata/IWBEP/GWSAMPLE_BASIC/'.
DATA(sap_client) = '002'.
DATA(destination_name_in_dest_srv) = 'ES5'.
"Destination Required for Basic Authentication. Credentials are stored in the SAP BTP destination service
DATA(lo_http_destination) = cl_http_destination_provider=>create_by_cloud_destination(
i_name = 'ES5'
i_authn_mode = if_a4c_cp_service=>service_specific
).
DATA(relative_url) = |{ service_relative_url }?sap-client={ sap_client }|.
DATA(http_client) = cl_web_http_client_manager=>create_by_http_destination( lo_http_destination ).
"remove any white spaces since the method set_uri_path does not check for white spaces
CONDENSE relative_url NO-GAPS.
" GET CSRF token
http_client->get_http_request( )->set_uri_path( i_uri_path = relative_url ).
http_client->get_http_request( )->set_header_fields( http_header_fields ).
DATA(http_response) = http_client->execute( if_web_http_client=>get ). "--> works
DATA(http_status_code) = http_response->get_status( ).
DATA(x_csrf_token) = http_response->get_header_field( 'x-csrf-token' ).
DATA(http_response_body) = http_response->get_text( ).
" Prepare POST request
IF demo_mode = abap_false.
relative_url = |{ service_relative_url }{ i_action_name }?sap-client={ sap_client }&{ i_query_parameters[ 1 ]-name }= '{ i_query_parameters[ 1 ]-value }' |.
"remove any white spaces since the method set_uri_path does not check for white spaces
CONDENSE relative_url NO-GAPS.
ELSE.
EXIT.
ENDIF.
http_client->get_http_request( )->set_uri_path( i_uri_path = relative_url ).
http_header_fields = VALUE #( ( name = if_web_http_header=>accept value = |application/json| )
( name = 'x-csrf-token' value = x_csrf_token ) ).
http_client->get_http_request( )->set_header_fields( http_header_fields ).
* DATA(http_request_body) = | { add json string } |.
* http_client->get_http_request( )->set_text( http_request_body ).
http_response = http_client->execute( if_web_http_client=>post ).
http_status_code = http_response->get_status( ).
response = http_response->get_text( ).
ENDMETHOD.
ENDCLASS.
