Swagger
Swagger is a set of tools for creating, generating, documenting, and testing RESTful services.
It is centered around a specification file(https://swagger.io/specification/), which contains the description of the REST services, much like a SOAP WSDL or OData metadata file.
There are many powerful tools in the Swagger family, which all are open source:
These tools are free and works in the browser. SAP also use Swagger as part of API management.
ABAP
A while ago I started building a tool for integrating ABAP and Swagger using an inside-out approach.
Lets jump right into it and see how it works, suppose I want to expose the methods of the following class as REST services:
CLASS zcl_todo DEFINITION PUBLIC CREATE PUBLIC.
PUBLIC SECTION.
METHODS create
IMPORTING
is_data TYPE ztodo_data
RETURNING
VALUE(rs_key) TYPE ztodo_key .
METHODS delete
IMPORTING
is_key TYPE ztodo_key .
METHODS list
RETURNING
VALUE(rt_list) TYPE ztodo_tt .
METHODS update
IMPORTING
iv_guid TYPE ztodo_key-guid
is_data TYPE ztodo_data .
ENDCLASS.
CLASS ZCL_TODO IMPLEMENTATION.
METHOD create.
DATA: ls_todo TYPE ztodo.
TRY.
rs_key-guid = cl_system_uuid=>if_system_uuid_static~create_uuid_c22( ).
CATCH cx_uuid_error.
ASSERT 0 = 1.
ENDTRY.
MOVE-CORRESPONDING rs_key TO ls_todo.
MOVE-CORRESPONDING is_data TO ls_todo.
INSERT ztodo FROM ls_todo.
ASSERT sy-subrc = 0.
ENDMETHOD.
METHOD delete.
DELETE FROM ztodo WHERE guid = is_key-guid.
ASSERT sy-subrc = 0.
ENDMETHOD.
METHOD list.
SELECT * FROM ztodo INTO TABLE rt_list. "#EC CI_NOWHERE
ENDMETHOD.
METHOD update.
DATA: ls_todo TYPE ztodo.
ls_todo-guid = iv_guid.
MOVE-CORRESPONDING is_data TO ls_todo.
UPDATE ztodo FROM ls_todo.
ASSERT sy-subrc = 0.
ENDMETHOD.
ENDCLASS.Interface ZIF_SWAG_HANDLER must be implemented, and metadata added for the methods to be exposed,
METHOD zif_swag_handler~meta.
FIELD-SYMBOLS: <ls_meta> LIKE LINE OF rt_meta.
APPEND INITIAL LINE TO rt_meta ASSIGNING <ls_meta>.
<ls_meta>-summary = 'List'(001).
<ls_meta>-url-regex = '/list$'.
<ls_meta>-method = zcl_swag=>c_method-get.
<ls_meta>-handler = 'LIST'.
APPEND INITIAL LINE TO rt_meta ASSIGNING <ls_meta>.
<ls_meta>-summary = 'Create'(002).
<ls_meta>-url-regex = '/create$'.
<ls_meta>-method = zcl_swag=>c_method-post.
<ls_meta>-handler = 'CREATE'.
APPEND INITIAL LINE TO rt_meta ASSIGNING <ls_meta>.
<ls_meta>-summary = 'Delete'(003).
<ls_meta>-url-regex = '/delete$'.
<ls_meta>-method = zcl_swag=>c_method-post.
<ls_meta>-handler = 'DELETE'.
APPEND INITIAL LINE TO rt_meta ASSIGNING <ls_meta>.
<ls_meta>-summary = 'Update'(004).
<ls_meta>-url-regex = '/update/(w+)$'.
APPEND 'IV_GUID' TO <ls_meta>-url-group_names.
<ls_meta>-method = zcl_swag=>c_method-post.
<ls_meta>-handler = 'UPDATE'.
ENDMETHOD.Add the handler to a custom SICF node, and thats about it! ABAP-Swagger will automatically generate a spec from the method definitions, and it is possible to use the Swagger UI to test the services. ABAP-Swagger is open source and works from 702 and up.
The full example can be found at https://github.com/larshp/todo_logic
Find more Open Source ABAP projects on dotabap.org
ABAP is like the sun, it will keep shining for a million years
- SAP Managed Tags:
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