CERN -> IPT Group -> FrameMaker at CERN
	Information Service User's Guide

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User-defined information types

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Introduction

The Information Service defines a number of simple IS types as it has been explained in the previous chapter. In addition to that a software developer can define his own types of information. A user-defined information type can be declared in C++ and Java languages as a class containing an arbitrary number of attributes. Each attribute cab be defined either as a single variable of one of the basic types, supported by IS, or as an array of one of those types. For the list of the IS supported types see Appendix D.

Although an information class can be declared manually (see Appendix A), it is strongly recommended to use a special procedure of defining an information type which is described in this chapter. Using this procedure offers additional benefits to a software developer:

• developer can provide text description for his own information type as well as for all the attributes of this type. This description will be available to all applications at run-time via the IS API.
• developer doesn't need to worry about compatibility of the Java and C++ class declarations for the same information type. For a number of reasons depicted in Appendix A this task is non-trivial.