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STRUCTURE

 

Again, the STRUCTURE section of a GPD declares the structural decomposition of a view. Beginning with the most all-inclusive concept, --- that for which the GPD is being defined, e.g. company memo, glossary, full document, etc. --- you break down the view into its logical subparts. These subparts may then need to be further broken down. That is, the STRUCTURE section tells whether a view is made up of subparts, and, if so, what those subparts are. The most elementary subparts is called `item' and is defined globally.

Again, figures 7.4 and 7.5 show examples of this.

Note that the most abstract concept (in the case of figure 7.4, this would be `document overview') is the name of the GPD and must also be the name in the GPD map of which the GPD is a member.

 


:  STRUCTURE of `full document' GPD

Figure 7.10 shows the STRUCTURE section of the `full document' GPD. From this, we see that a composition of type `full document' is made up of the subconcepts ``main title'', date, author, abstract, and subtext. (Note that ``main title'' is in quotes because there is a space in the name. Otherwise it would be treated as two subparts.) This is all of the STRUCTURE defined in this GPD. Additionally, the STRUCTURE of the subtext is inherited the `text' GPD (this is actually a link to that GPD) and the STRUCTURE of the abstract is inherited from the `document overview' GPD. One could expand on `General text view' in order to see the GPD from which subtext's STRUCTURE is inherited. Note that when you inherit the STRUCTURE of an object, you also inherit its ACCESS, FORMAT, and AUTOLINKS. The inverse is not true, however.

Which parts of the STRUCTURE section will actually be visible? If you think of the STRUCTURE section as building a tree structure, then the leaf nodes will be those visible on the screen. That is, those subparts of the STRUCTURE which are not broken down into subelements will be viewed. Therefore, given the GPD in figure 7.10, we see that the main title, date, author, subtext titles, and subtext paragraphs will be visible. sideways tree structure shown in figure 7.11 shows the internal xlincks representation of this tree structure, called the `reference structure'.

 


:  The reference structure

Therefore, the first step in writing a GPD is to decide what sort of structure you wish to have and to define locally what you cannot inherit from other GPD's.



next up previous contents index
Next: ACCESS Up: GPD Language Previous: GPD Language



Martin Sjolin
Mon May 29 19:53:45 MET DST 1995