As described in Chapter
1, an extension node consists of icons, an XML properties file, and
a SAS program. To build and deploy an extension node, you must learn
the structure of the individual parts as well as how the parts integrate
to form a whole. Unfortunately, there is no natural order in which
to discuss the individual parts. You cannot learn everything that
you need to know about one part without first learning something about
at least one of the other parts. This chapter provides as complete
an introduction to each of the parts as possible without discussing
their interdependencies. This chapter also provides the prerequisite
knowledge that you need to explore the interdependencies in subsequent
chapters.