Context hierarchy

The contexts used on the presentation server are arranged in a hierarchy starting at the server root context (serverCtx). The root context maintains session tables for all the clients that connect to the server, and keeps the resources (data and services) to be shared by all the processes and operations launched from the server.

The htmlSessionCtx is linked to the serverCtx statically, with the parent-child relationship being defined in XML definition files. Although the htmlSessionCtx can be used to demonstrate that the toolkit can provide multichannel control, it is not used to do so in this sample. Whenever a user session is established on the server, the startUpHtmlSessionOp operation creates a customerSessionCtx and dynamically chains it to the htmlSessionCtx. The startUpHtmlSessionOp also adds this context to the session table of the toolkit. The customerSessionCtx keeps all the resources that the operations and processors use during the user session. The toolkit chains the contexts of all operations and processors used during the session to the customerSessionCtx.

The following diagram illustrates the context hierarchy for the presentation server.