wissel.net :: JMP401 - Introduction to Composite Applications for IBM Lotus Notes and Domino and IBM Websphere Portal

If you ever have wondered what a composite application is, this session sheds light on it. In the beginning definitions were given: A composite (application) is a collection of components brought together for a business purpose. A component is a application that processes and renders data (like a nsf) and a component view is the visualization of these data. One big difference to classical application is that there is an additional step before you use an application. Developers build components in various ways (Domino, J2EE, Java etc.). After that a Assembler (a person) wires the components into a application. Since the assembly is a rather business driven exercise you can leave this step to power users. This allows to combine components in ways that haven't been predicted by the component developer.
So Composite applications are the business equivalent of the more free wheeling web 2.0 mashups. The major difference here: Notes Client components are not limited to HTML and URL linkage. IBM choose WSDL as definition language to wire components together. This relieves you from learning another interface standards.
The session gave a further overview of IBM's offerings to create components. They range from developer-only to user-suitable tools: Rational Application Developer, Lotus Component Designer, Domino Designer, Portlet Factory and the template editor.
At the core of the composite application sits the Property Broker. So every component calls the Property Broker that links published properties with published actions. E.g. a published property in a Notes view could be emailid and an action in a view could be GetCustomerByID. The very moment you select a document in a view the view reports the view reports the change of the emailid to the Property Broker. The Property Broker then calls all defined actions that have been literally wired to that property.
The demonstrations for both Notes and Portal were pretty slick.

What I liked:
Components bring the flexibility of Web 2.0 Mashups to the enterprise. Re-using WSDL as wiring protocol is a smart choice. The ability to mix'n match Portal and Client fosters reuse.

What I didn't like:
Properties and Actions currently need to be a 1:1 exact match. The property broker can't do transformations (e.g. just add the customer number from component 1 to an URL and then feed it into component 2). Here is work to do, that has been done elsewhere already.