Importing Abstract Services

You can use abstract services to support a top-down service development. An abstract service asset just contains abstract definitions like interface, operation, or message definitions. But, in contrast to a normal service asset, it does not contain the complete information that is necessary to call the web service that it represents. This means the required definitions are missing or not complete. You can supply the concrete definitions of an abstract service at a later time in order to turn the abstract service into a normal service. An abstract service is represented in the CentraSite registry by a normal service asset.

You can define abstract services by creating them from scratch or by importing WSDLs that comply with the WSDL 1.1 specification.

According to the WSDL 1.1 specification, a WSDL file does not need to contain any service or binding element. This kind of WSDL is called an abstract WSDL. Importing an abstract WSDL to CentraSite results in an abstract service. The name and the targetNamespace of the abstract service are taken from the name and the targetNamespace attributes of the WSDL's definition element. If the attributes are missing, the import is rejected.

To enable the import of name-less abstract WSDLs, the import dialog in CentraSite Control allows you to specify a name.

The minimal abstract WSDL that is supported just contains a definitions element with a name and a targetNamespace attribute.

An abstract service does not contain concrete definitions that refer to the registry objects for the abstract definitions. Instead the abstract service is linked to the abstract definitions through a HasParent relationship attribute. The relationship attribute points from the Interface objects to the Service object. Operation objects are not referred to directly since they are always part of an Interface. Types or messages do not need to be considered, since they are not represented in the registry. The HasParent relationship is classified as an aggregation relationship to ensure that the abstract definitions are considered properly when deleting, moving, or exporting the abstract service. The abstract WSDL is linked to the abstract service through an externalLink.

You can update an abstract service's definitions by attaching a WSDL to it. Attaching a WSDL overwrites all the registry objects that can be defined through a WSDL. This ensures that the attached WSDL reflects correctly the registry objects representing the service and its components. This also affects the service object itself. Objects that cannot be added by attaching a WSDL are not overwritten. The service object's name is not overwritten automatically when you attach a WSDL. This makes the name provided by the WSDL a technical name of a service. By default, the technical name is reflected by the local-name classification of the service object. You can align the service name with the technical name by marking the appropriate checkbox in the Attach WSDL dialog. For more information about attaching a WSDL to an abstract service, see Editing an Asset in the Catalog.