Saxon.Api

 

 

Saxon.Api

Class XdmNode

public class XdmNode
extends XdmItem

The class XdmNode represents a Node in the XDM Data Model. A Node is an XdmItem, and is therefore an XdmValue in its own right, and may also participate as one item within a sequence value.

An XdmNode is implemented as a wrapper around an object of type net.sf.saxon.NodeInfo. Because this is a key interface within Saxon, it is exposed via this API, even though it is a Java interface that is not part of the API proper.

The XdmNode interface exposes basic properties of the node, such as its name, its string value, and its typed value. Navigation to other nodes is supported through a single method, EnumerateAxis, which allows other nodes to be retrieved by following any of the XPath axes.

Property Summary
 Uri BaseUri

Get the base URI of the node.

 int ColumnNumber

Get the column number of the node in a source document.

 Uri DocumentUri

Get the document URI of the node.

 net.sf.saxon.om.NodeInfo Implementation

Escape hatch to the underlying class in the Java implementation

 int LineNumber

Get the line number of the node in a source document.

 XmlNodeType NodeKind

The kind of node, as an instance of System.Xml.XmlNodeType.

 QName NodeName

The name of the node, as a QName. Returns null in the case of unnamed nodes.

 string OuterXml

Return a serialization of this node as lexical XML

 XdmNode Parent

Get the parent of this node.

 Processor Processor

Get a Processor suitable for use with this XdmNode.

 XdmNode Root

Get the root of the tree containing this node.

 string StringValue

Get the string value of the node.

 XdmValue TypedValue

The typed value of the node, as an instance of XdmValue.

 

Method Summary
 IEnumerator<XdmNode> EnumerateAxis(XdmAxis axis)

Get an enumerator that supplies all the nodes on one of the XPath axes, starting with this node.

 IEnumerator<XdmNode> EnumerateAxis(XdmAxis axis, QName nodeName)

Get an enumerator that selects all the nodes on one of the XPath axes, provided they have a given name. The nodes selected are those of the principal node kind (elements for most axes, attributes for the attribute axis, namespace nodes for the namespace axis) whose name matches the name given in the second argument.

 bool Equals(object obj)

Two instances of XdmNode are equal if they represent the same node. That is, the Equals() method returns the same result as the XPath "is" operator.

 string GetAttributeValue(QName name)

Get a the string value of a named attribute of this element.

 int GetHashCode()

The hash code of a node reflects the equality relationship: if two XdmNode instances represent the same node, then they have the same hash code

 XmlNode getUnderlyingXmlNode()

Unwraps the underlying XmlNode object from the XdmValue. If the method does not wrap a XmlNode then a null is returned

 bool IsAtomic()

Determine whether the item is an atomic value

 string ToString()

Return a string representation of the node.

 void WriteTo(XmlWriter writer)

Send the node (that is, the subtree rooted at this node) to an XmlWriter

 

Property Detail

BaseUri

public Uri BaseUri {get; }

Get the base URI of the node.

ColumnNumber

public int ColumnNumber {get; }

Get the column number of the node in a source document.

For a document constructed using the document builder, this is available only if the line numbering option was set when the document was built (and then only for element nodes). If the column number is not available, the value -1 is returned. Line numbers will typically be as reported by a SAX parser; this means that the column number for an element node is the column number containing the closing ">" of the start tag.

DocumentUri

public Uri DocumentUri {get; }

Get the document URI of the node.

Implementation

public net.sf.saxon.om.NodeInfo Implementation {get; }

Escape hatch to the underlying class in the Java implementation

LineNumber

public int LineNumber {get; }

Get the line number of the node in a source document.

For a document constructed using the document builder, this is available only if the line numbering option was set when the document was built (and then only for element nodes). If the line number is not available, the value -1 is returned. Line numbers will typically be as reported by a SAX parser; this means that the line number for an element node is the line number containing the closing ">" of the start tag.

NodeKind

public XmlNodeType NodeKind {get; }

The kind of node, as an instance of System.Xml.XmlNodeType.

For a namespace node in the XDM model, the value XmlNodeType.None is returned.

NodeName

public QName NodeName {get; }

The name of the node, as a QName. Returns null in the case of unnamed nodes.

OuterXml

public string OuterXml {get; }

Return a serialization of this node as lexical XML

In the case of an element node, the result will be a well-formed XML document serialized as defined in the W3C XSLT/XQuery serialization specification, using options method="xml", indent="yes", omit-xml-declaration="yes".

In the case of a document node, the result will be a well-formed XML document provided that the document node contains exactly one element child, and no text node children. In other cases it will be a well-formed external general parsed entity.

In the case of an attribute node, the output is a string in the form name="value". The name will use the original namespace prefix.

Other nodes, such as text nodes, comments, and processing instructions, are represented as they would appear in lexical XML.

Parent

public XdmNode Parent {get; }

Get the parent of this node.

Returns either a document node, an element node, or null in the case where this node has no parent.

Processor

public Processor Processor {get; }

Get a Processor suitable for use with this XdmNode.

In most cases this will be the original Processor object used to create the DocumentBuilder that built the document that contains this node. If that Processor is not available, it will be a compatible Processor, one that shares the same underlying net.sf.saxon.Configuration, and hence is initialized with the same configuration settings, schema components, license features, and so on.

Note: the only case where the original Processor is not available is when the same Configuration is used with multiple APIs, for example mixing s9api and JAXP or XQJ in the same application.

Returns:

Returns a Processor suitable for performing further operations on this node, for example for creating a Serializer or an XPathCompiler.

Root

public XdmNode Root {get; }

Get the root of the tree containing this node.

Returns the root of the tree containing this node (which might be this node itself).

StringValue

public string StringValue {get; }

Get the string value of the node.

TypedValue

public XdmValue TypedValue {get; }

The typed value of the node, as an instance of XdmValue.

A DynamicError is thrown if the node has no typed value, as will be the case for an element with element-only content.

Method Detail

EnumerateAxis

public IEnumerator<XdmNode> EnumerateAxis(XdmAxis axis)

Get an enumerator that supplies all the nodes on one of the XPath axes, starting with this node.

The nodes are returned in axis order: that is, document order for a forwards axis, reverse document order for a reverse axis.

Parameters:

axis -  The axis to be navigated, for example XdmAxis.Child for the child axis.

EnumerateAxis

public IEnumerator<XdmNode> EnumerateAxis(XdmAxis axis,
QName nodeName)

Get an enumerator that selects all the nodes on one of the XPath axes, provided they have a given name. The nodes selected are those of the principal node kind (elements for most axes, attributes for the attribute axis, namespace nodes for the namespace axis) whose name matches the name given in the second argument.

The nodes are returned in axis order: that is, document order for a forwards axis, reverse document order for a reverse axis.

Parameters:

axis -  The axis to be navigated, for example XdmAxis.Child for the child axis.
nodeName -  The name of the required nodes, for example new QName("", "item") to select nodes with local name "item", in no namespace.

Equals

public override bool Equals(object obj)

Two instances of XdmNode are equal if they represent the same node. That is, the Equals() method returns the same result as the XPath "is" operator.

Parameters:

obj - The object node to be compared

GetAttributeValue

public string GetAttributeValue(QName name)

Get a the string value of a named attribute of this element.

Returns null if this node is not an element, or if this element has no attribute with the specified name.

Parameters:

name - The name of the attribute whose value is required

GetHashCode

public override int GetHashCode()

The hash code of a node reflects the equality relationship: if two XdmNode instances represent the same node, then they have the same hash code

getUnderlyingXmlNode

public XmlNode getUnderlyingXmlNode()

Unwraps the underlying XmlNode object from the XdmValue. If the method does not wrap a XmlNode then a null is returned

Returns:

The underlying XmlNode

IsAtomic

public override bool IsAtomic()

Determine whether the item is an atomic value

Returns:

false (the item is not an atomic value)

ToString

public override string ToString()

Return a string representation of the node.

This method returns the value of the XdmNode.OuterXml property. To get the string value of a node as defined in XPath, use the XdmNode.StringValue property.

WriteTo

public void WriteTo(XmlWriter writer)

Send the node (that is, the subtree rooted at this node) to an XmlWriter

Note that an XmlWriter can only handle a well-formed XML document. This method will therefore signal an exception if the node is a document node with no children, or with more than one element child.

Parameters:

writer -  The XmlWriter to which the node is to be written