An example of implementing a call-triggering flow

Figure 8 shows a more detailed of a call-triggered flow, initiated, in this case, by an access client that is a client browser.

Figure 8. Sample call-triggered flow initiated by a client browser


As shown in Figure 8:

  1. The client browser issues a request in a specific protocol and format (for example, an HTTP protocol and an XML data format).
  2. The enterprise Web server loads a servlet to handle the request. This servlet is the access client. It is programmed to look for the name of the CORBA-compliant Interchange Server (from the CORBA registry).
  3. The access client, via an IIOP connection, logs in to InterChange Server by creating an access session with the IgetInterchangeAccessSession() method of the IAccessEngine interface of the Server Access Interface API.
    Note:
    To execute the collaboration, InterChange Server does not create any threads of its own, but uses the CORBA thread. See the Collaboration Development Guide for details on how collaborations use threads.
  4. The access client uses the IcreateBusinessObjectFrom() method in the IInterchangeAccessSession interface to transform the XML data into a generic IBM WebSphere InterChange Server business object. In response to this method call, the Server Access Interface within ICS invokes the XML data handler to perform the data transformation and then returns the business object to the access client.
  5. The access client uses the IexecuteCollaboration() method in the IInterchangeAccessSession interface to send the triggering access call, which contains the business object as the triggering access data. This process requests the execution of a collaboration that manipulates the business object.
    Note:
    The Server Access Interface API also provides the IexecuteCollaborationExtFmt() method, which combines step 4 and step 5 into a single method call.
  6. Traversing connectors, the collaboration places requests, sorts, and fetches data, manipulating enterprise applications as required. The collaboration returns requested data, or results of requested actions, to the access client in business-object format.
  7. If the access client has used the IexecuteCollaborationExtFmt() method to issue the access request, it does not need to explicitly perform the actions in step 6. The IexecuteCollaborationExtFmt() method automatically transforms the business object back to its original format (in this case, the XML format) and returns this serialized data to the access client.
  8. The results are delivered to the client browser.

As shown in Figure 8, the Web server handling the call loads a servlet to handle the call, which connects to WebSphere InterChange Server.

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