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An OSGi bundle for Saxon-HE
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2013 Saxonica Limited.
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.s9api;
import net.sf.saxon.om.NamePool;
import net.sf.saxon.om.NodeInfo;
import net.sf.saxon.om.Sequence;
import net.sf.saxon.om.StructuredQName;
import net.sf.saxon.pattern.NameTest;
import net.sf.saxon.query.QueryResult;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.tree.iter.AxisIterator;
import net.sf.saxon.tree.wrapper.VirtualNode;
import net.sf.saxon.type.Type;
import javax.xml.transform.Source;
import java.net.URI;
import java.net.URISyntaxException;
/**
* This class represents a node in the XDM data model. A Node is an {@link XdmItem}, and is therefore an
* {@link 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 {@link net.sf.saxon.om.NodeInfo}.
* Because this is a key interface within Saxon, it is exposed via this API.
*
* 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, {@link #axisIterator},
* which allows other nodes to be retrieved by following any of the XPath axes.
*
* Note that node identity cannot be inferred from object identity. The same node may be represented
* by different XdmNode instances at different times, or even at the same time. The equals()
* method on this class can be used to test for node identity.
* @since 9.0
*/
public class XdmNode extends XdmItem {
/**
* Construct an XdmNode as a wrapper around an existing NodeInfo object
* @param node the NodeInfo object to be wrapped. This can be retrieved using the
* {@link #getUnderlyingNode} method.
* @since 9.2 (previously a protected constructor)
*/
public XdmNode(NodeInfo node) {
super(node);
}
/**
* Get the kind of node.
* @return the kind of node, for example {@link XdmNodeKind#ELEMENT} or {@link XdmNodeKind#ATTRIBUTE}
*/
public XdmNodeKind getNodeKind() {
switch (getUnderlyingNode().getNodeKind()) {
case Type.DOCUMENT:
return XdmNodeKind.DOCUMENT;
case Type.ELEMENT:
return XdmNodeKind.ELEMENT;
case Type.ATTRIBUTE:
return XdmNodeKind.ATTRIBUTE;
case Type.TEXT:
return XdmNodeKind.TEXT;
case Type.COMMENT:
return XdmNodeKind.COMMENT;
case Type.PROCESSING_INSTRUCTION:
return XdmNodeKind.PROCESSING_INSTRUCTION;
case Type.NAMESPACE:
return XdmNodeKind.NAMESPACE;
default:
throw new IllegalStateException("nodeKind");
}
}
/**
* Get the name of the node, as a QName
*
* @return the name of the node. In the case of unnamed nodes (for example, text and comment nodes)
* return null.
*/
/*@Nullable*/ public QName getNodeName() {
NodeInfo n = getUnderlyingNode();
switch (n.getNodeKind()) {
case Type.DOCUMENT:
case Type.TEXT:
case Type.COMMENT:
return null;
case Type.PROCESSING_INSTRUCTION:
case Type.NAMESPACE:
if (n.getLocalPart().isEmpty()) {
return null;
} else {
return new QName(new StructuredQName("", "", n.getLocalPart()));
}
case Type.ELEMENT:
case Type.ATTRIBUTE:
return new QName(n.getPrefix(), n.getURI(), n.getLocalPart());
default:
return null;
}
}
/**
* Get the typed value of this node, as defined in XDM
*
* @return the typed value. If the typed value is atomic, this will be returned as an instance
* of {@link XdmAtomicValue}
* @throws SaxonApiException if an error occurs obtaining the typed value, for example because
* the node is an element with element-only content
*/
public XdmValue getTypedValue() throws SaxonApiException {
try {
Sequence v = getUnderlyingNode().atomize();
return XdmValue.wrap(v);
} catch (XPathException e) {
throw new SaxonApiException(e);
}
}
/**
* 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.
* @return the line number of the node, or -1 if not available.
*/
public int getLineNumber() {
return getUnderlyingNode().getLineNumber();
}
/**
* 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. Column numbers
* will typically be as reported by a SAX parser: this means that the column number for an element node is the
* position of the closing ">" of the start tag.
* @return the column number of the node, or -1 if not available.
*/
public int getColumnNumber() {
return getUnderlyingNode().getColumnNumber();
}
/**
* Get a JAXP Source object corresponding to this node, allowing the node to be
* used as input to transformations or queries.
*
* The Source object that is returned will generally be one that is acceptable to Saxon interfaces
* that expect an instance of javax.xml.transform.Source. However, there is no guarantee
* that it will be recognized by other products.
*
* In fact, the current implementation always returns an instance of
* net.sf.saxon.om.NodeInfo.
* @return a Source object corresponding to this node
*/
public Source asSource() {
return getUnderlyingNode();
}
/**
* Get an iterator over the nodes reachable from this node via a given axis.
*
* @param axis identifies which axis is to be navigated
* @return an iterator over the nodes on the specified axis, starting from this node as the
* context node. The nodes are returned in axis order, that is, in document order for a forwards
* axis and in reverse document order for a reverse axis.
*/
public XdmSequenceIterator axisIterator(Axis axis) {
AxisIterator base = getUnderlyingNode().iterateAxis(axis.getAxisNumber());
return new XdmSequenceIterator(base);
}
/**
* Get an iterator over the nodes reachable from this node via a given axis, selecting only
* those nodes with a specified name.
*
* @param axis identifies which axis is to be navigated
* @param name identifies the name of the nodes to be selected. The selected nodes will be those
* whose node kind is the principal node kind of the axis (that is, attributes for the attribute
* axis, namespaces for the namespace axis, and elements for all other axes) whose name matches
* the specified name.
* For example, specify new QName("", "item") to select nodes with local name
* "item", in no namespace.
* @return an iterator over the nodes on the specified axis, starting from this node as the
* context node. The nodes are returned in axis order, that is, in document order for a forwards
* axis and in reverse document order for a reverse axis.
*/
public XdmSequenceIterator axisIterator(Axis axis, QName name) {
int kind;
switch (axis) {
case ATTRIBUTE:
kind = Type.ATTRIBUTE;
break;
case NAMESPACE:
kind = Type.NAMESPACE;
break;
default:
kind = Type.ELEMENT;
break;
}
NamePool pool = getUnderlyingNode().getNamePool();
int nameCode = pool.allocate("", name.getNamespaceURI(), name.getLocalName());
NameTest test = new NameTest(kind, nameCode, pool);
AxisIterator base = getUnderlyingNode().iterateAxis(axis.getAxisNumber(), test);
return new XdmSequenceIterator(base);
}
/**
* Get the parent of this node
*
* @return the parent of this node (a document or element node), or null if this node has no parent.
*/
public XdmNode getParent() {
NodeInfo p = getUnderlyingNode().getParent();
return (p == null ? null : (XdmNode) XdmValue.wrap(p));
}
/**
* Get the string value of a named attribute of this element
* @param name the name of the required attribute
* @return null if this node is not an element, or if this element has no
* attribute with the specified name. Otherwise return the string value of the
* selected attribute node.
*/
public String getAttributeValue(QName name) {
NodeInfo node = getUnderlyingNode();
return node.getAttributeValue(name.getNamespaceURI(), name.getLocalName());
}
/**
* Get the base URI of this node
*
* @return the base URI, as defined in the XDM model. The value may be null if no base URI is known for the
* node, for example if the tree was built from a StreamSource with no associated URI, or if the node has
* no parent.
* @throws IllegalStateException if the base URI property of the underlying node is not a valid URI.
*/
public URI getBaseURI() {
try {
String uri = getUnderlyingNode().getBaseURI();
if (uri == null) {
return null;
}
return new URI(uri);
} catch (URISyntaxException e) {
throw new IllegalStateException("baseURI", e);
}
}
/**
* Get the document URI of this node.
* @return the document URI, as defined in the XDM model. Returns null if no document URI is known
* @throws IllegalStateException if the document URI property of the underlying node is not a valid URI.
* @since 9.1
*/
public URI getDocumentURI() {
try {
String systemId = getUnderlyingNode().getSystemId();
return (systemId == null || systemId.length() == 0 ? null : new URI(systemId));
} catch (URISyntaxException e) {
throw new IllegalStateException("documentURI", e);
}
}
/**
* The hashcode is such that two XdmNode instances have the same hashCode if they represent the same
* node. Note that the same node might be represented by different XdmNode objects, but these will
* compare equal.
*
* @return a hashCode representing node identity
*/
public int hashCode() {
return getUnderlyingNode().hashCode();
}
/**
* The equals() relation between two XdmNode objects is true if they both represent the same
* node. That is, it corresponds to the "is" operator in XPath.
*
* @param other the object to be compared
* @return true if and only if the other object is an XdmNode instance representing the same node
*/
public boolean equals(Object other) {
return other instanceof XdmNode &&
getUnderlyingNode().isSameNodeInfo(((XdmNode) other).getUnderlyingNode());
}
/**
* The toString() method returns a simple XML serialization of the node
* with defaulted serialization parameters.
*
* 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.
*
* In the case of a namespace node, the output is a string in the form of a namespace
* declaration, that is xmlns="uri" or xmlns:pre="uri".
*
* Other nodes, such as text nodes, comments, and processing instructions, are
* represented as they would appear in lexical XML.
*
* For more control over serialization, use the {@link Serializer} class.
*
* @return a simple XML serialization of the node. Under error conditions the method
* may return an error message which will always begin with the label "Error: ".
*/
public String toString() {
NodeInfo node = getUnderlyingNode();
if (node.getNodeKind() == Type.ATTRIBUTE) {
String val = node.getStringValue().replace("\"", """);
val = val.replace("<", "<");
val = val.replace("&", "&");
return node.getDisplayName() + "=\"" + val + '"';
} else if (node.getNodeKind() == Type.NAMESPACE) {
String val = node.getStringValue().replace("\"", """);
val = val.replace("<", "<");
val = val.replace("&", "&");
String name = node.getDisplayName();
name = (name.equals("") ? "xmlns" : "xmlns:" + name);
return name + "=\"" + val + '"';
}
try {
return QueryResult.serialize(node);
} catch (XPathException err) {
throw new IllegalStateException(err);
}
}
/**
* Get the Processor that was used to construct this node.
* @return the Processor used to construct this node, either via a {@link DocumentBuilder},
* or by executing XSLT or XQuery code.
* @since 9.2
*/
public Processor getProcessor() {
Object p = getUnderlyingNode().getConfiguration().getProcessor();
if (p instanceof Processor) {
return (Processor)p;
} else {
// I don't think this can happen, hence not a documented exception
throw new IllegalStateException("Node was not created using a s9api Processor");
}
}
/**
* Get the underlying Saxon implementation object representing this node. This provides
* access to classes and methods in the Saxon implementation that may be subject to change
* from one release to another.
*
* @return the underlying implementation object
*/
public NodeInfo getUnderlyingNode() {
return (NodeInfo) getUnderlyingValue();
}
/**
* In the case of an XdmNode that wraps a node in an external object model such as DOM, JDOM,
* XOM, or DOM4J, get the underlying wrapped node
* @return the underlying external node if there is one, or null if this is not an XdmNode that
* wraps such an external node
* @since 9.1.0.2
*/
public Object getExternalNode() {
NodeInfo saxonNode = getUnderlyingNode();
if (saxonNode instanceof VirtualNode) {
Object externalNode = ((VirtualNode)saxonNode).getRealNode();
return (externalNode instanceof NodeInfo ? null : externalNode);
} else {
return null;
}
}
}