10.5 and
Chapter 5 for a detailed description). The modeling concepts include ???proxy,???
???location,??? and ???signaling actions,??? essential for specifying IP telephony servers.
These same concepts are already de?¬?ned as elements in the XML schema, and the
property values of the modeling concepts are attributes of the XML elements. Having
generators produce the con?¬?guration in XML gives signi?¬?cant and obvious
productivity and quality improvements. With the modeling language, it is far
more dif?¬?cult to design services that have errors: something that is all too easy in
handwritten CPL/XML.
10.2.3 Choosing Computational Models
Domain concepts do not exist independently: they relate to each other. These
connections can be illustrated in the models too with supporting modeling concepts.
FIGURE 10.4 Modeling ?¬?nancial and insurance products for a J2EE web application with a
DSM language based on domain expert concepts
IDENTIFYING AND DEFINING MODELING CONCEPTS 237
The way domain concepts should be connected leads to ?¬?nding a suitable model of
computation (MOC, see Section 4.2.2). Usually, the main approach can be identi?¬?ed
relatively easily: should we focus on specifying static structures, behavior, or both.
When inspecting details of the domain there are, however, big differences, and it is the
details that matter when using models for code generation.
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