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Procedure documentationMatching Service Interfaces for Point-to-Point Communication Locate this document in the navigation structure

 

If you develop a point-to-point communication using Web service runtime with the outside-in approach, first create service interfaces in the Enterprise Services Repository. For P2P communication you need an outbound service interface for the call at the consumer side and an inbound service interface for implementing the service at the provider side. In the ES Repository you can match an inbound service interface to an outbound service interface. It is not obligatory to do this, but it just makes configuration easier to execute later on.

More information: Interface Pattern

In the ES Builder you can match the service interfaces:

  • Automatically by using a wizard

    The wizard creates an outbound service interface that matches a given inbound service interface. It also creates a link between the service interfaces, which indicate that they match and can be used for point-to-point communication.

  • Manually by creating service interfaces and assigning them to each other.

Recommendation Recommendation

SAP recommends that you use the wizard to automatically create and match service interfaces.

End of the recommendation.

For an existing inbound interface in the ES Repository, the wizard creates an outbound interface. It then matches the two service interfaces. In the wizard, you specify a name for the outbound interface, the software component version, and the namespace under which this interface should reside. If both the inbound and outbound interfaces reside in the same software component version, then the wizard only creates a new outbound interface that matches the inbound interface under the defined target namespace. However, if the interfaces reside in two different software component versions, then all the objects from the source are copied to the target software component version and a new outbound interface is created. The wizard displays the list of objects under the source software component version that will be copied to the target software component version. The copied objects are included in the change list and should be activated.

When the source and target software component versions are different, then references to objects from underlying software component versions are not copied to the target software component versions.

The referenced objects are not copied in the following scenarios:

  • Service interface, for example, belongs to software component version A and refers to a data type that belongs to software component version B. If you create matching service interfaces in a new software component version C, then the wizard will not copy the referenced data type from software component version B to C.

  • Aggregated data types that refer to data types from different underlying software component versions are not copied.

In such cases, the wizard displays a message for each of the objects that are not copied to the target software component version. You need to manually copy the referenced files to the target software component version or define dependencies from the target software component version to the underlying software component versions to match the service interfaces.

Note Note

IDOCs and RFCs cannot be copied from one software component version to the other. In such cases, you have to manually import them into the target software component version and then assign the message to the outbound service interface.

End of the note.

Prerequisites

When you match service interfaces manually, then one of them should be editable. They should also comply with the rules described below.

When Do Service Interfaces Match?

In the simplest case, the service interfaces are identical apart from name and category (inbound or outbound), that is, if the outbound service interface and all interface objects, are referenced by this service interface, are copies of the corresponding objects of an inbound service interfaces. If, however, the consumer only wants to call one operation of the inbound service interface, for example, it is not necessary to create the other inbound service interface operations in the outbound service interface as well.

Simply put, the operations and corresponding outbound service interface data structures can be a subset of the operations and corresponding data structures of the inbound interface referenced. The service interface editor provides a check for the service interface pairs to determine the compatibility of the inbound and outbound service interface. This check is performed in multiple steps to determine compatibility (starting service interfaces, across operations and down to data types). The following section describes the steps to be able to estimate for a service interface assignment whether two service interfaces match.

Matching Service Interfaces

Two service interfaces match each other if the following conditions are fulfilled:

  • One service interface is of the outboundcategory and the other service interface if of the inbound category. Neither of the service interfaces can be abstract.

  • Both of the service interfaces have the same interface pattern.

  • There is a matching operation in the inbound service interface for each of the operations in the outbound service interface (see below).

Matching Operations

An inbound service interface operation matches an outbound service interface operation (and the other way around) if the following conditions are met:

  • Both operations must have the name mode (asynchronous or synchronous).

  • Both operations must have the same Operation Pattern.

  • The message type for the request, which must be referenced by each operation, must have the same name and same XML Namespace. The names of the operations may differ. The same applies for the response with synchronous communication.

  • If the inbound service interface operation references a fault message type, the outbound service interface operation must also reference a fault message type with the same name and XML Namespace.

  • The data types of the message types, which the outbound service interface for the request message references (and, if necessary, for the response and fault message) must be compatible with the corresponding inbound service interface data types (see below).

Matching Data Types

The check whether the corresponding data types are compatible with each other is sufficient until the comparison of the facets of an XSD type. The data types are compared using the same method as other objects: The structures are compatible if they contain the same fields (elements and attributes) and if these fields have compatible types, frequencies, details, and default values. There are however a few restraints, for example the target structure can contain attributes or elements that do not appear in the outbound structure, but if these are not required and where the frequency is optional or prohibited (attributes) or minOccurs=0 (elements). (Which structure is the outbound structure and which is the target structure is the same as the direction of the message exchange).

Caution Caution

The check cannot check the entire XSD schema language. The check does not necessarily report an error for service interfaces whose operations reference external messages if the data structures are incompatible. There are the following restrictions in particular:

End of the caution.

  • The data structures compared must both be correct. For example, not all correct facets are skipped or considered in the compatibility check.

  • Some XSD schema language elements that can appear in a reference to an external message in the data structure are not supported. Therefore, the elements redefine and any, for example, as well as the attributes blockDefault, finalDefault, and substitutionGroup.

  • The comparison of structures is, for example, restricted to the following:

    • The details whiteSpace and pattern are not checked

    • If the facet pattern is used for the outbound structure field, all the other details are not checked.

    • If the order of subelements if different between the outbound and target field, a warning is displayed.

Procedure

Matching Service Interfaces Using the Wizard

  1. Open the inbound service interface in the service interface editor.

  2. In the editor menu, select   Tools   Create Matching Interface  .

  3. Follow the instructions on the wizard.

Note Note

You can only create a matching outbound interface for a given inbound interface in the ES Repository.

End of the note.
Matching Service Interfaces Manually

You can enter the following reference for the service interfaces depending on which service interface can be changed:

  • If the outbound service interface can be changed, you can enter one of multiple matching inbound service interfaces there. The outbound service interface is shown as an unchangeable entry for each inbound service interface (even when the inbound service interface is in processing).

  • If the inbound service interface can be changed, you can enter one of multiple matching outbound service interfaces there. The inbound service interface is shown as an unchangeable entry for each outbound service interface (even when the outbound service interface is in processing).

    Mutual entries are possible but are not required.

    1. Call the service interface editor for the changeable service interface.

    2. Go to the Matching Service Interfaces tab.

    3. For each service that you want to reference enter a row in the table and reference each of the matching service interfaces using the search help, for example.

      Note Note

      Due to the large volume of data in the ES Repository the ES Builder cannot check during the search if the service interfaces match or not. Therefore nonmatching service interfaces are also offered in the search help.

      End of the note.

    4. Check your assignments using theCheck Assignment of Matching Service Interfaces (Check Assignment of Matching Service Interfaces) function).

Result

On the Matching Service Interface tab page, the service interface editor identifies the matching service interfaces with a blue arrow.