Extension of generated Idocs types

Question

hello,
does anybody knows why I can not create extension of generated (means in table EDBAS-GENERATED = 'X') idocs?
I tried to extend idoc BATMAS03 on R/3 Ecc 6 and got message:
message e099(b1) with
         'Action is not possible for generated idoctypes'
In former version of R/3 4.6C it was possible to extend such IDoc BATMAS02 (generated one) without any problems.
Of course I found in program MSED5F02  in routine CREATE_EXT_STRUCTURE new (in comparison to 4.6C) extra check which protects against extension of generated IDocs, but I want to get to know what was behind that decision or how to workaround that problem.
Thanks in advance,
Marcin

Answer 1

Hi,
User Exits are used to populate data in new segments added and to read them
back which provides extension to existing idocs.
IDOC EXTENSIONS
SAP delivers Basic IDOC types such as DEBMAS02, MATMAS02, ORDERS02, and WMMBID01. By extending the Basic IDOC type, you are actually creating a new IDOC type. You create a new segment with the additional fields. This new segment has to be associated with one of the existing Basic IDOC segments. Then you create a new extension type, which is associated with the Basic IDOC type. This results in a new IDOC type. In order for ALE function modules to relate to this new IDOC type, the IDOC type is linked to the corresponding message type. Note that you should not add fields to existing segments but should create a new segment and associate it with an existing segment. This, in a nutshell, is the process of creating IDOC extensions.
In our example, the Basic IDOC type DEBMAS02 is used to communicate Customer Master data to the SAP Customer Master application. Even though the application has a screen to enter and store a contact personâs business address (see Figure 1), DEBMAS02 does not have a segment or fields that communicate the contact personâs business address. If your business requires that this business address be communicated to the other system through the ALE interface for Customer Master, then you have to extend the DEBMAS02 IDOC type, and enhance the corresponding ALE function module.
In DEBMAS02 the contact person fields are present in segment E1KNVKM and the business address of the contact person is stored on the SADR SAP table. You need to create a new segment, Z1SADRX, that is associated with E1KNVKM. This will be done in the process of creating an extension type ZDEBMASX. This extension type will then be associated with a new IDOC type, ZDEBMASZ. IDOC type ZDEBMASZ will be linked to message type DEBMAS for Customer Master. The final step in the IDOC extension process is to check the new objects. This check also verifies the structural integrity of the IDOC type. Letâs look at each of these steps in more detail.
1. Create an Extension Type and a New Segment.
First, determine the fields on table SADR that you are going to provide for in the new segment Z1SADRX. You need fields for name, street, city, region, and country to give the business address of the contact person. You also need fields for the address number. ADRNR is a field in SAP tables such as SADR that uniquely identifies the address of an entity. This field is cross-referenced from other tables to the SADR table to obtain the full description of the address. Because this is an IDOC type for master data, the first field of the new segment will be MSGFN. The message function field informs the receiving system of the action to be taken for that particular segment. In the code that you write for populating the new segment, the value of the message function is the same as that of the parent segment E1KNVKM. In all, you will have 12 fields in segment Z1SADRX (see Table 1).
To create an extension type and new segment:
Use transaction WE30 or from WEDI go to Development -> IDOC types.
Enter ZDEBMASX for Object Name.
Choose Extension Type.
Click on Create.
You will see a pop-up screen. Choose Create New, and enter a description. For version 4.x, enter DEBMAS02 in the Linked Basic Type field. Enter.
You will see a screen with ZDEBMASX and its description in the first line. Click on this line, and press Create. For version 4.x, expand the tree of segments, and place the cursor on E1KNVKM.
You will see a pop-up screen. Enter E1KNVKM as the reference segment. Enter.
For 4.x, press Create after placing the cursor on segment E1KNVKM.
You will see a line appear with E1KNVKM hierarchically below ZDEBMASX, with a description "Customer Master contact person (KNVK)."
Click on this line and press Create. You will receive a message indicating that the new segment being created will be a child segment of E1KNVKM. Enter. A pop-up box appears for the new segment.
Enter Z1SADRX as the segment type, 1 for Minimum, 1 for Maximum. Leave Mandatory segment unchecked. These entries imply that there is only one Z1SADRX segment for every occurrence of the E1KNVKM segment, and also that this segment is not mandatory. Note that if the parent segment is not mandatory, then the child segment should not be mandatory, because this could result in a syntax error during the creation or processing of the IDOC.
For 4.x, you must first create the IDOC segment Z1SADRX (Iâll explain why in a moment) from the menu path WEDI -> IDOC -> Development -> IDOC Segment.
Click on Segment Editor.
On the next screen, click on Create.
Enter a development class for the object. Enter.
This will take you to the screen for segment definition. Enter a description for the segment. Enter the field name, data element, and the data element documentation name. In most cases, all three fields may have the same values. If you are using a field in the segment that is not present in the ABAP/4 data dictionary, you must first create the domain, data element, field, and appropriate documentation before using it in the new segment.
Enter these three columns for all 12 fields. Save.
Click on Generate/Activate, F3 to step back.
From screen Maintain Segment, go to Segment Type -> Release. A checkbox now appears beside the segment definition Z1SADRX (see Figure 2). Check this box. Save. Save again to store the descriptions of the segment, F3 to step back.
Save the extension type.
It is possible to have several new segments with relevant Basic IDOC type parent segments in a single extension type. However, you can form only one IDOC type based on a single extension type.
Pls reward helpful points.
Regards,
Ameet