Message Mappings (SAP Library - SAP Exchange Infrastructure (BC-XI))

Message Mappings

Use

A message mapping refers to a mapping of messages and is supported by a graphical mapping editor. The editor enables you to design a structure mapping between any two XML structures and the connection to a value mapping.

The mapping tool generates Java source code from the graphical mapping description that is then compiled and packed in a Jar file that the Integration Engine executes at runtime.

Features

The mapping editor can import any schema ((fault) message types, imported RFCs, or IDocs) from the Integration Repository, as well as XML schema definitions (XSD) and any XML file. In the case of XSD files (the repository schemas also use this format), the mapping editor generates an XML representation for both the source structure and the target structure.

Main Functions Area of the Mapping Editor

Once you have created a message mapping the system navigates to the mapping editor Design tab page. In the screenshot below, the request schema of an RFC module and a message type have been loaded and a simple mapping defined (the tab page was removed from the Integration Builder beforehand):

This graphic is explained in the accompanying text

You have the following options when defining a message mapping:

The functions in the Main Function Toolbar relate to the entire mapping. For example, you can save your mapping or automatically assign fields with the same name to each other.
When you create a new message mapping the Structure Overview in the mapping editor is initially empty. Here you must specify a repository schema for both the source structure and the target structure or import an XML or XSD file. The mapping editor imports the data and displays the XML representation for the mapping in the Structure Overview. In this screen area, the source structure is on the left and the target structure is on the right. Source structure fields then have to be mapped to target structure fields. You have various options for displaying the source and target structure (Tree View, Tree and Table View, display as a text document, or display in the browser) which you can select from.
The structure overview is strongly linked to the Data-Flow Editor, which you use to describe the mapping of one or more source fields to one target field. This type of mapping is also referred to as a Target Field Mapping. If a field in the target structure has already been mapped, you can navigate to the respective mapping by double-clicking the corresponding target field in the structure overview.

Therefore, a message mapping comprises various target field mappings. Once you have defined a mapping for each mandatory target field your message mapping is complete. To test your message mapping, navigate to the Test tab page (see: Testing Message Mappings).

Functions of the Object Toolbar

Function	Use
Compile	Provided that the message mapping is complete, you can use this function to compile the Java source files generated for the mapping.
Update	If you called a repository schema in the mapping editor that has since been changed in the Integration Repository, the changes will not be visible in the mapping editor. To apply changes of this type to the source and target structures, choose Update.
Delete Mapping	Deletes all target field mappings.
Text Preview	Displays all target field mappings including the functions used as text (the data-flow editor is hidden from view). Lines in red indicate missing target field mappings. The Quickinfo for a green target field displays the corresponding mapping.
Map Selected Fields and Substructures if Names Are Identical	Before you execute this function, first select a node in both the source and target structure that belong to each other. You can then automatically assign subnodes that have identical names (names are case sensitive here). This function is particularly useful for simple mappings, for example from RFC XML to Proxy XML.

Functions of the Context Menu

To define target mappings for different positions of a target element that occurs frequently, the context menu for the target structure has the function Duplicate Subtree (see: Duplicating Subtrees). You have the option of deleting any duplicates that you create.

Activities

To define a mapping between two XML structures, proceed as follows:

Create a message mapping in the design maintenance of the Integration Builder (also see: Creating a New Object).

Using the structure overview and the data-flow editor, assign one or more source fields to a target field. This type of mapping is also called a Target Field Mapping. It is possible to assign one source field to multiple target fields (see: Assigning a Field).

If necessary, enhance the target field mapping in the data-flow editor. To do so, connect the source fields to the target fields by using the standard functions of the mapping editor. You can also create user-defined functions in Java in the mapping editor and then also use them in the data-flow editor (see also: Data-Flow Editor).

Carry out the last two steps for at least all mandatory target fields.

Result

The mapping is complete and ready for testing when all the fields in the target structure have either green or white icons. A yellow icon indicates that a target field mapping is incomplete, while a red icon indicates that a target field is unassigned.