NodeInfo interface

The NodeInfo interface (net.sf.saxon.om.NodeInfo on Java, or Saxon.Hej.om.NodeInfo on C#) represents a node of an XML document. The methods on this class follow the XPath data model closely.

The NodeInfo interface is classified as part of Saxon's system programming interface which means it is available for use by applications that require a close level of integration with Saxon, but it is not guaranteed to be 100% stable between releases. For a higher level of stability, use the XdmNode interface on Java, or XdmNode on C#.

Because the interface is intended primarily for internal use, it is essentially the same across Java and C#: in particular it uses Java coding conventions such as methods with names like getNodeKind().

The most commonly used methods on NodeInfo include:

getNodeKind()	Gets a `short` identifying the node type (for example, element or attribute). The values are consistent with those used in the DOM, and are referenced by constants in the class net.sf.saxon.type.Type.
getDisplayName(), getLocalPart(), getPrefix(), getURI()	These methods get the name of an element or attribute, or its various parts. The `getDisplayName()` method returns the QName as used in the original source XML.
getAttributeValue()	Gets the value of a specified attribute, as a `String`.
getStringValue()	Gets the string value of a node, as defined in the XPath data model.
getUnicodeStringValue()	Gets the string value of a node, as a `UnicodeString`. This is a Saxon-specific string representation designed to be more efficient that the system `String` class for many common operations, especially when it contains characters with codepoints above 65535.
atomize()	Gets the typed value of a node, as defined in the XPath 2.0 data model. This is in general a sequence of atomic values, so the result is an AtomicSequence. In most cases the typed value will either be a single atomic value or an empty sequence; a single atomic value will be represented using class AtomicValue (which implements `AtomicSequence`) or one of its subclasses such as StringValue. An empty sequence is best recognized by calling `atomicSequence.getLength() == 0`.
getParent()	Gets the NodeInfo representing the parent element.
iterateAxis()	Returns an AxisIterator object that can be used to iterate over the nodes on any of the XPath axes. The first argument is an integer identifying the axis; the second is a NodeTest (a simple form of pattern) which can be used to filter the nodes on the axis. Supply `null` if you want all the nodes on the axis.

For other methods, see the NodeInfo JavaDoc documentation.

C# interface documentation is not published for internal interfaces such as NodeInfo. The Java documentation of the corresponding class will usually give a reliable guide to the methods available, since the two products are based on the same source code. There are some differences, however: for example, the Java version of NodeInfo implements the super-interface ActiveSource and therefore implements the method deliver(); neither the super-interface nor the method is available in the C# version. For an accurate description of the class and its methods, navigate to the class in an IDE such as Visual Studio.

It is possible (though not easy) to provide your own implementation of the NodeInfo interface, perhaps allowing Saxon queries to run directly against some non-XML data source. There are helper methods in the Navigator class that reduce the amount of code you need to write to achieve this. See the implementations that map NodeInfo to DOM, DOM4J, JDOM or XOM to see how it is done.