| Represents a subset of the XPath expression language as described in section 7.4.2 of the Web
Feature Implementation Specification 1.1.0 (but is used by other OGC specifications as well).
This specification does not require a WFS implementation to support the full XPath language. In
order to keep the implementation entry cost as low as possible, this specification mandates that
a WFS implementation must support the following subset of the XPath language:
- A WFS implementation must support abbreviated relative location paths.
- Relative location paths are composed of one or more steps separated by the path
separator '/'.
- The first step of a relative location path may correspond to the root element of the
feature property being referenced or to the root element of the feature type with the
next step corresponding to the root element of the feature property being referenced
- Each subsequent step in the path must be composed of the abbreviated form of the
child:: axis specifier and the name of the feature property encoded as the principal node
type of element. The abbreviated form of the child:: axis specifier is to simply
omit the specifier from the location step.
- Each step in the path may optionally contain a predicate composed of the predicate
delimiters '[' and ']' and a number indicating which child of the context node is to be selected.
This allows feature properties that may be repeated to be specifically referenced.
- The final step in a path may optionally be composed of the abbreviated form of the
attribute:: axis specifier, '@', and the name of a feature property encoded as the
principal node type of attribute::.
author:
Markus Schneider
author:
last edited by: $Author: apoth $
version:
$Revision: 9344 $, $Date: 2007-12-27 08:21:56 -0800 (Thu, 27 Dec 2007) $
See Also: PropertyPathStep |
