Syntax Diagram Conventions
The descriptions of the XML resource files include diagrams describing the syntax of the elements in the files. The diagrams look something like this:
<content-types version="4" > <field-group>...<field-group>* <relation-type-group>...<relation-type-group>* <content-type>...<content-type>+ ANY-FOREIGN-ELEMENT* </content-types>
In these diagrams, anything appearing in plain black characters is literal content: that is, it should be entered in the file exactly as shown. Anything appearing in black, italic characters is a placeholder that must be replaced by something else. The only such placeholders currently in use are:
-
ANY-FOREIGN-ELEMENT - This placeholder can be replaced by any foreign element. A foreign element is an element from a different namespace. This is mainly intended to allow you to enter elements from the
interface-hints
namespace (see interface-hints). You can, however, insert elements from any other namespace if you have the need. -
ANY-ELEMENT - This placeholder can be replaced by any element from this namespace or any other.
Anything appearing in this color is neither literal content nor a placeholder, but has one of the following special meanings:
- ()
-
Encloses a set of alternatives, only one of which may be selected.
- |
-
Separates the alternatives in a () set.
- ?
-
Indicates that the preceding element is optional.
- *
-
Indicates that the preceding element may appear 0 or more times.
- +
-
Indicates that the preceding element may appear 1 or more times.
- ...
-
Represents possible content in an element or attribute.
Element order is not significant in any of the
XML publication resource files. The syntax diagram shown above seems
to suggest that a field-group
element must appear
before a relation-type-group
element, but this is
not the case: the elements can in fact appear in
any order.