About XML Document Structure

The XPath processor operates on a tree representation of XML data that looks like the following figure:

The root node has no actual text associated with it. You can think of the file name as the root node. A document can include zero or more comments and zero or more processing instructions.

A document element is required, and there can be only one. The document element contains all elements in the document. For example:

In the preceding figure, bookstore.xml is the name of a file that contains XML data. There is a comment near the beginning of the document that starts with "This file represents a ..." The document element is bookstore. The immediate children of bookstore include an attribute, a namespace declaration (not supported by Stylus Studio), three book elements (one is in the my namespace), and a magazine element. The book and magazine elements contain elements and attributes, which are shown in the figure that appears in Tree Representation of a Sample XML Document.

 
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