Gateway Service using the OData Channel Approach (ABAP Coding) for Media Links(Photo,Document)

[arunchembra1]

Introduction

This document will help you  to Implement a Gateway Service using the OData Channel approach (ABAP Coding)  for Media Links. Gateway Service is implemented by creating two ABAP classes – Model Provider class and Runtime Data Provider class. In this document, i will cover the creation of the Model Provider class and a Runtime Data Provider class.

Prerequisites:

1.     Gateway IWBEP system: IW_BEP 200 SP5 and above

2.     Gateway IWFND system: IW_FND 250(Gateway HUB) SP3

Step 1 : Goto Transaction SE80

Step 2 : Create Model Provider Class ZCL_TEST_MPC

Step 3 : Save Model Provider Class in local object

Step4 : Goto Model Provider Class click on Properties Tab and assign superclass /IWBEP/CL_MGW_PUSH_ABS_MODEL as shown below.

Step 5 : Go to methods and redefine the method called DEFINE.

method DEFINE.

data:
lo_annotation         type ref to /iwbep/if_mgw_odata_annotation,
lo_data_object        type ref to /iwbep/if_mgw_odata_entity_typ,
lo_model_object       type ref to /iwbep/if_mgw_odata_entity_typ,
lo_model_entity_type  type ref to /iwbep/if_mgw_odata_entity_typ,
lo_entity_set         type ref to /iwbep/if_mgw_odata_entity_set,
lo_complex_type       type ref to /iwbep/if_mgw_odata_cmplx_type,
lo_association        type ref to /iwbep/if_mgw_odata_assoc,
lo_complex_type2      type ref to /iwbep/if_mgw_odata_cmplx_type,
lo_association2       type ref to /iwbep/if_mgw_odata_assoc,
lo_nav_property       type ref to /iwbep/if_mgw_odata_nav_prop,
lo_property           type ref to /iwbep/if_mgw_odata_property,
lo_action             type ref to /iwbep/if_mgw_odata_action,
lo_parameter          type ref to /iwbep/if_mgw_odata_parameter,
lo_ref_constraint     type ref to /iwbep/if_mgw_odata_ref_constr.

super->define( ).

* carrier object gets defined
lo_data_object = model->create_entity_type( 'IMAGE' ).
lo_property = lo_data_object->create_property( 'EMPLOYEE_ID' ).
lo_property->set_is_key( ).
lo_property->set_filterable( abap_true ).
lo_data_object->create_property( 'MIME_CODE' ).
lo_property = lo_data_object->create_property( 'CONTENT' ).
lo_property = lo_data_object->create_property( 'URL' ).

lo_data_object->bind_structure( 'ZEMP_DOCUMENT' ).

* setting a data object as media type means that it gets a special semantic by having a url and allows streaming etc.
lo_data_object->set_is_media( ).
 

endmethod.

Step 6 : Create Model Provider Class ZCL_TEST_DPC

Step 7 : Goto Model Provider Class click on Properties Tab and assign superclass  /IWBEP/CL_MGW_PUSH_ABS_DATA as shown below.

Step 8 : Redefine method GET_STREAM and paste the below code and replace the function module 'ZHR_DOCUMENT' with your function module which will give binary data. Or directly pass binary data to ls_stream-value without function module.

method /IWBEP/IF_MGW_APPL_SRV_RUNTIME~GET_STREAM.

data: ls_stream    type         ty_s_media_resource,
lo_api    type ref to  if_mr_api,
er_entity type ref to data,
lr_entity type ref to data,
l_photo type xstring,
i_pernr type  persno.

READ TABLE it_key_tab WITH KEY name = 'EMPLOYEE_ID’ INTO ls_key_tab.

IF sy-subrc = 0.
MOVE ls_key_tab-value TO i_pernr.

ENDIF.

call function 'ZHR_DOCUMENT'
exporting
i_pernr = i_pernr
importing
pdf_doc = l_photo.

ls_stream-value = l_photo.

copy_data_to_ref( exporting is_data = ls_stream
changing  cr_data = er_stream ).



endmethod.

Step 9 : Goto Transaction SPRO Maintain Models and  Click Create button

Step 10  : Enter the Model Provider Class name as shown below

Step 11  : Goto Transaction SPRO Maintain Services and  Click Create button

Step 12  : Enter the Model Provider Class name as shown below, Assign Model and save.

Step 13  : Activate the Service in Gateway System

http://XXXXXXXXXXXXXXXXXXXXXXX:9000/sap/opu/odata/sap/ZTES_SERVICE/$metadata

To read the Media Link( Photo,Document) we need to add suffix /$value to the GetEntity(Read)

  URL  as shown below.

http://XXXXXXXXXXXXXXXX:9000/sap/opu/odata/sap/ZTES_SERVICE/IMAGECollection(‘12345678’)/$value