A GPD consists of a collection of declarations divided into five sections: STRUCTURE, ACCESS, FORMAT, EXPAND, and AUTOLINKS. Each of these sections is in turn divided into direct and indirect references; direct references are defined in that GPD and indirect references are defined in another GPD. In the subsequent sections, we will go into more detail about each of the GPD sections and give examples of how to use them.
All declarations in all sections are concerned with information that should be tied to the infonodes within the reference structure (the internal representation in xlincks). The kind of information to be bound to that keyword is dependent upon which section of the GPD it is in. Each reference in the section, whether an indirect or direct reference, is a sequence of ``keyword `values to keywords' ''. For example, such a declaration might be
paragraph
LINK TEXT Paragraph
where `paragraph' is the keyword and `LINK TEXT Paragraph' is the value
assigned it. (In this case, this declaration is in the ACCESS
section.) The `paragraph' keyword is regarded as a label for a concept
that occurs within the type of object being defined in the GPD. For
example, such a keyword may be `paragraph', `title', `correspondent',
`department head', `author', and so on, where the keyword is a
conceptual part of the objects for which the GPD is being written. In
the `text' GPD, for example, `text' is defined as having a singular
`title', a plural `paragraph', and a plural `subtext' decomposition.
These are the keywords for this particularly GPD, which can be seen in
figure 7.3.
Each section in the GPD has a particular function.
Figure: STRUCTURE of `document overview' GPD
Figure: STRUCTURE of `company menu' GPD
paragraph
LINK TEXT Paragraph
which means all of the linkitems in the link group TEXT:Paragraph. A common singular item is an attribute value, such as:
title
ATTR TEXT Title
Secondly, the ACCESS section tells where to retrieve a view subpart within database objects. This will be explained in section 7.2.2. Figures 7.6 and 7.7 show examples of the ACCESS section.
Figure: ACCESS of `document overview' GPD
Figure: ACCESS of `company menu' GPD
Figure: EXPAND of `document overview' GPD
Figure: EXPAND of `company menu' GPD