XI Process Integration (XI) Design Time

Communication in SAP Exchange Infrastructure is interface-based. That is, messages are generally created by calling an interface. SAP Exchange Infrastructure supports two approaches for implementing a cross-system process:

· Outside-In: You create the relevant interfaces for the cross-system process in the Integration Builder. These message interfaces are a programming language-independent description in XML. You use these message interfaces to generate callable interfaces (proxies) in target systems.

· Inside-Out: The functions that are to be called using SAP Exchange Infrastructure already exist in the application systems. To be able to use an interface description of these functions in the design process, you import specific interface descriptions to the Integration Repository by using the Integration Builder (see External Programs and Descriptions at the end of this section).

See also: Interface-Based Message Processing.

You can also combine the two approaches. Regardless of the interfaces that you require for your cross-system process, you have to work simultaneously in the following development environments during design time:

· You use the Integration Builder to design and define all objects affecting message exchange (see below). In some cases you can use external tools and import objects to the Integration Repository.

· You implement message processing in your application program by using the development environment of your application systems.

Design Objects in the Integration Builder

The following graphic provides an overview of the design objects that developers can create in the Integration Repository by using the Integration Builder.

The Integration Builder allows you to edit the following objects by using the corresponding graphical editors (shown on the left-hand side of the graphic):

· Integration scenarios describe the communication between application components on a higher level of abstraction. Integration processes are executable processes on the Integration Server. See: Implementing Collaborative Processes.

· Mappings are used to define structure or value mappings between messages that are exchanged between interfaces. You can define these mappings as graphical message mappings or you can import them into the Integration Repository as XSLT or Java archives.

· Context objects mask access to elements or attributes in the payload. For example, you can specify elements in a deeply nested message structure in conditions by using the short name of a context object, thus sparing you the long hierarchy path.

· Data types and message types describe the structure of messages that are to be exchanged using message interfaces. Developers use message interfaces to generate proxies in application systems (the graphic only shows outside-in development).

The entire content of the Integration Repository can be shipped. Together, these objects are referred to as Process Integration Content, abbreviated to XI content. Using a software component version from the System Landscape Directory you define the smallest possible shipment unit for a number of objects that belong together in the Integration Repository. SAP software component versions are also the basis for shipment units from application objects in SAP systems so that XI content and application content can be assigned to a joint software component version in the SAP system.

See also: Software Logistics.

External Programs and Descriptions

SAP XI uses various XML standards (see also: Messages). The advantage of this is that you can reuse external programs and schema definitions. The following graphic gives an overview of the formats that you can import to and export from the Integration Repository.

· You can import externally-defined integration processes as BPEL documents (Business Process Execution Language).

· As an alternative to graphical message mappings (which the Integration Builder uses to generate Java programs), you can also import externally-defined XSLT mappings or Java mappings to the Integration Repository, to execute at runtime (see: XSLT and Java Mappings). It is also possible to combine different mapping program types with each other (see: References Between Mapping Programs).

· You can import interface descriptions for IDocs and RFCs (see Importing IDocs and RFCs).

· You can import external definitions (DTD, XSD, and WSDL) and reuse message schemas from these documents within the Integration Builder.