oid_xpath_integer
oid_xpath_integer (oid, expr[, nsOid])
This function evaluates an XPath expression in the context of an OID. This function evaluates expr as a floating-point number, rounds to the nearest integer, and returns that integer.
• oid — The object to use as the context node.
• expr — A valid XPath expression that can be represented as an integer.
Do not use expressions that contain position() or last(). They do not work in this context. Use the preceding-sibling or following-sibling axes instead to achieve the desired results. For example:
◦ count(preceding-sibling::*)=0 will test that the context node is the first child of its parent.
◦ count(preceding-sibling::para)=1 will test that the context node is the second para child of its parent.
◦ count(following-sibling::*)=0 is a viable alternative to position()=last()
• nsOid (optional) — The node used for resolving namespace prefixes in the XPath expression.
The nsOid parameter is useful when you need to evaluate the same XPath expression against many XML documents. Those documents might use a different namespace prefix than the XPath expression. If you provide an OID where the namespace prefix is declared, its URI can be matched up with the document instances regardless of the namespace prefixes they used. For example, you might have a configuration file that uses XPath expressions to specify naming rules with namespace prefixes declared on its root element.
Non-numeric results are converted to numbers using standard XPath rules:
• Strings are parsed as floating-point numbers.
• Boolean expressions are converted to 1 or 0.
• Node set expressions are first converted to strings, then parsed. A run-time error occurs if the result cannot be represented as an integer.
To handle errors, call this function from within a catch.
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