Connector for SAP Business Suite - API description Part 3 - Implementing custom processing modules

Overview of required API methods

The following table should provide a brief overview of which API functions need to be implemented to achieve a certain amount of external functionality.

Requirement

Datahandler

get_DataObjects

Get_MetaInfo

Get_List

Get_Detail

modify

delete

update_temp_key

Display internal tables

GENERIC_VIEW

O

X

X

Search help function

GENERIC_VIEW

O

X

X

Functional calls

GENERIC_FUNCTION

X

Trigger function with data storage in the external system

GENERIC_FUNCTION

X

Data modelling externally, data storage in SAP

GENERIC_STORE

X

X

X

X

X

Trigger function with data storage in SAP

DEVELOPER_API

O

X

X

X

O

Make SAP business objects (e.g. Customer) available

DEVELOPER_API

O

X

X

X

O

Inherited attributes of the root object

The following table contains attributes that are defined during the instancing of the processing modules. These can be used within the API methods.

Attribute

Use

More information

CURRENT_API_FUNCTION

Currently called function of the RFC API

API RFC functions

CURRENT_LOG_GUID

GUID within the LOG table

Logging

CUST_GLOBAL

Global customizing

Basic settings

CUST_OBJECT

Customizing of the processing module

Registering processing modules

CUST_MAPPING

Customizing of the finding

Mapping external data groups to processing modules

IX_CONTROL

External control structure

Control structure

KEY_SEPARATOR

Separator for compound table keys

Key information

PARAMETERS

Determined parameters by priority: Object -> Mapping -> External parameters

Logging

Inherited methods of the root object

The following table contains methods that are implemented in the root object and used by the framework. The implementation examples from the 4th Part of the API description - sample coding - contains some ABAP coding that demonstrates how to call these methods. By redefining existing methods within custom processing modules, you can encroach on the standard processing considerably (e.g. converting data types).

Method

Use

More information

Z_IF_IA_IXA_INTREXX_API*

API methods

API Interface

CHECK_BAPIRET2

Checking of BAPIRET2 structures for errors and message attachments

GET_FIELD

Identify the single value from a table with incoming data

Data exchange

GET_FIELD_WITH_X_FLAG

Like GET_FIELD with update information for BAPI calls

Data exchange

GET_FIELDS_FROM_STRUC

Transfer incoming data to a transfer structure

Data exchange

GET_NEW_NUMBER_KEY

Simple number sequencing

Number sequencing

GET_SERVER_CONFIG

Identify value from an external configuration value

Control structure

LOCKING*

Modelling of locking concept

Locking concept

MAP_BAPIRET2_TAB_TO_IXA_MSG

Mapping of BAPI messages to an internal format

MAP_FIELDVALUE*

Convert values from an internal to external presentation (and vise versa) depending on the data type

Conversion - Internal vs external

MAP_INTREXX_LANGUAGE_TO_SAP

Mapping of the portal language from Intrexx to SAP

MAP_IXA_MESSAGE_TO_BAL_LOG

Mapping of the internal messages to the format of the application log

Expanded message logging

MSG_APPEND

Append a message for the external caller

Messages

GET_FIELD

Transfer a single value to the export

Data exchange

SET_RESULTS_FROM_STRUC

Transfer a transfer structure to the export

Data exchange

Checklist: Create a new processing module

Create a class

Each processing module consists of an ABAP object's class that is inherited from a root class of the portal framework. To do this start the transaction SE80 for example. You can create a new ABAP class via the Context menu (right-mouse button).

Provide the new class with a technical name (perhaps based on your internal naming conventions) and a label.

Afterwards, an additional edit field will open via the highlighted button where you can specify which existing class the new class should inherit its properties from. Specify a class from the framework.

Examples:

  • Z_CL_IA_IXA_OBJECT (WAS 6.x)

  • Z_CL_IA_IXA_OBJECT46 (SAP Basis 4.6)

If you have not assigned the new class to the local packet $TMP, a popup will open for the transport request after you have confirmed your entry with Save. The new class has been created and can now be activated. The activation can be started via the button, for example.

A selection of the objects to be activated will then open.

After confirming here, the new class is activated and can be used.

Redefining the API methods

The extension concept of the portal framework means that the identified processing modules overwrite the corresponding API methods of the API interface. Here, for example, the API method "GET_DETAIL" is redefined. To do this, position the cursor over the API method and click the button.

Subsequently, the ABAP workbench generates an inheritance of the selected method with a coding suggestion for calling the same-named method of the parent object.

It makes sense here to open the inherited method of the parent object and add custom coding before or after it. In many cases however, the entire method must be reimplemented. The basic framework for such a reimplementation could be used as shown in the following coding:

method Z_IF_IA_IXA_INTREXX_API~GET_DETAIL.

				* -------------- init
				  cv_processed = 'X'.  
				  ev_error     = 'X'.

				* -------------- get inbound parameters

				* -------------- initial check routines

				* -------------- process

				* -------------- fill outbound parameters

				* -------------- finally set no error  
				  ev_error    = ' '.

				endmethod.

This suggestion assumes that the method can be exited in the case of errors at any time using the ABAP command "EXIT". The error flag is only deleted at the end.

Create a transfer structure

For the tabular transfer of data via the API to an external caller a transfer structure is implemented. The external caller identifies the setup of this structure (e.g. field name and technical properties of these fields) via the API method GET_METAINFO. Experience shows that it is a good idea to define this transfer structure as a structure in the ABAP dictionary. You can then treat this structure, for example, as a table and use the API methods for the registered processing module of the datahandler "GENERIC_VIEW" (e.g. "GET_METAINFO"). In the following, the creation of such a transfer structure will be described as an example. Transfer structures usually contain a subset of actually available SAP tables or views, or rather fields from BAPI structures. If possible, you should use the same field names here that the actual SAP processing functions (e.g. BAPI functional modules) use. Transferring data can then be achieved in a time-saving manner via the ABAP command "MOVE-CORRESPONDING". Transfer structures can defined SAP data in a table row that actually is not available or is not identifiable via joins. Examples of this are:

  • Customer data with address and communication information in a row

  • Process text fields (e.g. text field from status code)

The invoking API method is responsible that all necessary conversions take place before the data is added to the exit parameter of the API methods. A transfer structure is created either via transaction SE11 or once more in the ABAP workbench SE80.

The technical name of the new structure is requested in a popup.

You then define the field names and data elements of your transfer structure in the structure maintenance. The transfer structure should contain all key fields needed for the identification later.

Activate the structure.

Registering the processing module

The newly created class must be registered for the processing module in the customizing. The following screenshot demonstrates the registration of the previously created processing class that only refers to the transfer structure "YIXAPI_DEMO" with the key field "PARTNER".

Alternatively, it is also possible to implement generic processing modules without a specific reference to a transfer structure. In this case, the actual transfer structure is identified from other parameters generically (e.g. from the externally used data group name). As a naming convention for the required technical name "OBJECTTYPE", the following prefixes are recommended:

  • Generic modules - GENERIC_*

  • Modules with BAPI reference - BAPI_*

Otherwise, the technical names should contain references to internal projects and provide an explanation of the expected function (e.g. "*ORDER*").

Finding the processing module

The processing module that was just registered is not yet found by the framework. The Customizing of the finding needs to be adjusted to do this. The following screenshot demonstrates this for the explained example.

In the future, the new processing module can be accessed via the datahandler "DEVELOPER_API" and the external data group "YIXAPI_DEMO".

Testing and debugging

This section describes the options as to how new processing modules, and their finding, can be tested and debugged.

Test the finding via the RFC API

The externally called RFC functions of the RFC API are listed in the chapter API RFC functions. Each of these RFC functions can be tested and debugged internally via the transaction "SE37 ABAP". The following example demonstrates this by using the implemented API method "GET_DETAIL" of the process module from the chapter Checklist: Create a new processing module. The externally called RFC functional module for the API method "GET_DETAIL" is "Z_IA_IXA_API_GET_DETAIL". This is now started with SE37.

A window with the functional module interface will open.

The parameter IS_CONTROL plays an important role in the finding of the processing module.

The parameter can be edited by clicking the button.

An optically improved view is created by clicking on the button . Filling in the fields "IX_DATAGROUP" and "IX_DATAHANDLER" is enough for the test. The values need to be the same as those entered in the finding.

After confirming and returning to the interface view, the RFC functional module can be started with the F8 key or by clicking on the button. Depending on the implemented API module, other parameters may need to be populated.

After the start, the interface view contains the return values.

An initial export parameter "EV_ERROR" is a good sign that a processing module with these parameters was found and executed. To find out whether the correct processing module was started, a breakpoint can be added to the corresponding API method of the processing module.

Debugging within the SAP system

This section describes a debugging option without an external call. With this, the ABAP developer can test the basic functionality of a processing module before an external user calls the RFC API functions remotely. To do this, place a breakpoint within the ABAP coding (e.g. at the start of the API method) using the CTRL-SHIFT-F12 key or by clicking the button.

In newer releases (Basis SAP Gateway >6.10), a window can now be opened to select the type of breakpoint to be created. In this case, a "Session Breakpoint" should be selected.

The breakpoint is shown in the coding.

Afterwards, the test via the call of the responsible RFC functional module should be repeated. The transaction SE37 must be restarted for this. The debugger will open when the breakpoint is reached.

The ABAP develop can now test in debug mode and find errors as usual.

External debugging

External debugging enables troubleshooting and testing of ABAP coding that is invoked externally (e.g. via RFC from the portal). In doing so, errors can be found that originate from the externally calling parameter populating in a different manner than what is expected. This option is available in SAP systems that use an ABAP Basis >= 6.10. The external debugging must be activated in the settings of the ABAP Workbench (Transaction SE80, Menu "Help / Settings").

It is also possible to debug users that deviate from the ABAP developer or login names. In this way, you can monitor, for example, the technical user that the external caller uses to log in to the RFC API. Please make sure that the user entered here has sufficient permissions (e.g. debugging, ABAP development) and is categorized as a dialog user (e.g. even if only temporarily during the test phase). When the popup for selecting the type of breakpoint appears, please select "External breakpoint".

So that the breakpoint is effective for the external caller, the external system must potentially log in once more. If the debugger is not opened after the API function's call, even though the internal test works, the SAP documentation about externally activated debugging contains additional support for the troubleshooting. In most cases, you will find what you're looking for in the *.TRC files of the remotely used RFC API.

Externally activated debugging

Another method for activating the debug mode is made available by the externally used SAP RFC SDK. This makes it possible, for example when using the SAP Java Connector, to activate the debug mode externally (see documentation on SAP Java Connector). External callers that use the SAP Java Connector may provide parameters that remove this behavior. A limitation of this method is that this only functions stabily on MS Windows and an SAPGUI needs to be installed on the external caller's computer. This usually excludes this alternative because the server in the data center should not be used for development and tests.

More information

General

Installation

Creating a connection

Integration in applications

SAP Script Generator

SAP Trust Manager SSO configuration

API description Part 1 - Overview

API description Part 2 - SAP Portal Plugin

API description Part 4 - Sample coding

Developer's Manual Part 1

Developer's Manual Part 2 - Integration scenario, SAP external data group

Developer's Manual Part 3 - Scripting integration scenario

Developer's Manual Part 4 - Personalized SAP Access / Single Sign On (SSO)

Developer's Manual Part 5 - Add-ons

Developer's Manual Appendix

Developer's Manual - Example Coding