net.sf.saxon.om
Interface NodeInfo

All Superinterfaces:
Item, PullEvent, Source, ValueRepresentation
All Known Subinterfaces:
DocumentInfo, ExtendedNodeInfo, SiblingCountingNode, VirtualNode
All Known Implementing Classes:
AbsentExtensionElement, AnnotationParent, DataElement, DocumentImpl, DocumentWrapper, DocumentWrapper, DocumentWrapper, DocumentWrapper, ElementImpl, ElementWithAttributes, ExtensionInstruction, LiteralResultElement, NamespaceIterator.NamespaceNodeImpl, NodeImpl, NodeWrapper, NodeWrapper, NodeWrapper, NodeWrapper, Orphan, SaxonAssign, SaxonCallTemplate, SaxonCollation, SaxonDoctype, SaxonEntityRef, SaxonImportQuery, SaxonScript, SaxonWhile, SchemaElement, SQLClose, SQLColumn, SQLConnect, SQLDelete, SQLInsert, SQLQuery, SQLUpdate, StrippedDocument, StrippedNode, StyleElement, TextFragmentValue, TinyDocumentImpl, TinyNodeImpl, TinyTextImpl, UnconstructedDocument, UnconstructedElement, UnconstructedParent, UnknownElement, VirtualCopy, VirtualDocumentCopy, VirtualUntypedCopy, WhitespaceTextImpl, XSDAnnotation, XSDAny, XSDAnyAttribute, XSDAssert, XSDAttribute, XSDAttributeGroup, XSDComplexContent, XSDComplexContentRestriction, XSDComplexType, XSDCompositor, XSDDocumentation, XSDElement, XSDExtension, XSDFacet, XSDFieldOrSelector, XSDGroup, XSDIdentityConstraint, XSDImport, XSDInclude, XSDList, XSDNotation, XSDRedefine, XSDSchema, XSDSimpleContent, XSDSimpleContentRestriction, XSDSimpleType, XSDSimpleTypeRestriction, XSDUnion, XSLAnalyzeString, XSLApplyImports, XSLApplyTemplates, XSLAttribute, XSLAttributeSet, XSLCallTemplate, XSLCharacterMap, XSLChoose, XSLComment, XSLCopy, XSLCopyOf, XSLDecimalFormat, XSLDocument, XSLElement, XSLFallback, XSLForEach, XSLForEachGroup, XSLFunction, XSLGeneralIncorporate, XSLGeneralVariable, XSLIf, XSLImport, XSLImportSchema, XSLInclude, XSLKey, XSLMatchingSubstring, XSLMessage, XSLNamespace, XSLNamespaceAlias, XSLNextMatch, XSLNumber, XSLOtherwise, XSLOutput, XSLOutputCharacter, XSLParam, XSLPerformSort, XSLPreserveSpace, XSLProcessingInstruction, XSLResultDocument, XSLSequence, XSLSort, XSLStringConstructor, XSLStylesheet, XSLTemplate, XSLText, XSLValueOf, XSLVariable, XSLVariableDeclaration, XSLWhen, XSLWithParam

public interface NodeInfo
extends Source, Item, ValueRepresentation

The NodeInfo interface represents a node in Saxon's implementation of the XPath 2.0 data model.

Note that several NodeInfo objects may represent the same node. To test node identity, the method isSameNodeInfo(NodeInfo) should be used. An exception to this rule applies for document nodes, where the correspondence between document nodes and DocumentInfo objects is one to one. NodeInfo objects are never reused: a given NodeInfo object represents the same node for its entire lifetime.

This is the primary interface for accessing trees in Saxon, and it forms part of the public Saxon API. The only subclass of NodeInfo that applications should normally use is DocumentInfo, which represents a document node. Methods that form part of the public API are (since Saxon 8.4) labelled with a JavaDoc "since" tag: classes and methods that have no such label should not be regarded as stable interfaces.

The interface represented by this class is at a slightly higher level than the abstraction described in the W3C data model specification, in that it includes support for the XPath axes, rather than exposing the lower-level properties (such as "parent" and "children") directly. All navigation within trees, except for a few convenience methods, is done by following the axes using the iterateAxis(byte) method. This allows different implementations of the XPath tree model to implement axis navigation in different ways. Some implementations may choose to use the helper methods provided in class Navigator.

Note that the stability of this interface applies to classes that use the interface, not to classes that implement it. The interface may be extended in future to add new methods.

New implementations of NodeInfo are advised also to implement the methods in interface ExtendedNodeInfo, which will be moved into this interface at some time in the future.

Since:
8.4
Author:
Michael H. Kay

Field Summary
static int ALL_NAMESPACES
          Copy all in-scope namespaces
static int[] EMPTY_NAMESPACE_LIST
           
static int IS_DTD_TYPE
          Bit setting in the returned type annotation indicating a DTD_derived type on an attribute node
static int IS_NILLED
          Bit setting for use alongside a type annotation indicating that the is-nilled property is set
static int LOCAL_NAMESPACES
          Copy namespaces declared (or undeclared) on this element, but not namespaces inherited from a parent element
static int NO_NAMESPACES
          Don't copy any namespace nodes.
 
Fields inherited from interface net.sf.saxon.om.ValueRepresentation
EMPTY_VALUE_ARRAY
 
Method Summary
 Value atomize()
          Get the typed value.
 int compareOrder(NodeInfo other)
          Determine the relative position of this node and another node, in document order.
 void copy(Receiver out, int whichNamespaces, boolean copyAnnotations, int locationId)
          Copy this node to a given Receiver.
 boolean equals(Object other)
          The equals() method compares nodes for identity.
 void generateId(FastStringBuffer buffer)
          Construct a character string that uniquely identifies this node.
 String getAttributeValue(int fingerprint)
          Get the string value of a given attribute of this node
 String getBaseURI()
          Get the Base URI for the node, that is, the URI used for resolving a relative URI contained in the node.
 Configuration getConfiguration()
          Get the configuration used to build the tree containing this node.
 int[] getDeclaredNamespaces(int[] buffer)
          Get all namespace declarations and undeclarations defined on this element.
 String getDisplayName()
          Get the display name of this node, in the form of a lexical QName.
 int getDocumentNumber()
          Get the document number of the document containing this node.
 DocumentInfo getDocumentRoot()
          Get the root node, if it is a document node.
 int getFingerprint()
          Get fingerprint.
 int getLineNumber()
          Get line number.
 String getLocalPart()
          Get the local part of the name of this node.
 int getNameCode()
          Get name code.
 NamePool getNamePool()
          Get the NamePool that holds the namecode for this node
 int getNodeKind()
          Get the kind of node.
 NodeInfo getParent()
          Get the NodeInfo object representing the parent of this node
 String getPrefix()
          Get the prefix of the name of the node.
 NodeInfo getRoot()
          Get the root node of the tree containing this node
 String getStringValue()
          Return the string value of the node as defined in the XPath data model.
 String getSystemId()
          Get the System ID for the node.
 int getTypeAnnotation()
          Get the type annotation of this node, if any.
 String getURI()
          Get the URI part of the name of this node.
 boolean hasChildNodes()
          Determine whether the node has any children.
 int hashCode()
          The hashCode() method obeys the contract for hashCode(): that is, if two objects are equal (represent the same node) then they must have the same hashCode()
 boolean isSameNodeInfo(NodeInfo other)
          Determine whether this is the same node as another node.
 AxisIterator iterateAxis(byte axisNumber)
          Return an iteration over all the nodes reached by the given axis from this node
 AxisIterator iterateAxis(byte axisNumber, NodeTest nodeTest)
          Return an iteration over all the nodes reached by the given axis from this node that match a given NodeTest
 
Methods inherited from interface javax.xml.transform.Source
setSystemId
 
Methods inherited from interface net.sf.saxon.om.Item
getStringValueCS, getTypedValue
 

Field Detail

EMPTY_NAMESPACE_LIST

static final int[] EMPTY_NAMESPACE_LIST

IS_DTD_TYPE

static final int IS_DTD_TYPE
Bit setting in the returned type annotation indicating a DTD_derived type on an attribute node

See Also:
Constant Field Values

IS_NILLED

static final int IS_NILLED
Bit setting for use alongside a type annotation indicating that the is-nilled property is set

See Also:
Constant Field Values

NO_NAMESPACES

static final int NO_NAMESPACES
Don't copy any namespace nodes.

See Also:
Constant Field Values

LOCAL_NAMESPACES

static final int LOCAL_NAMESPACES
Copy namespaces declared (or undeclared) on this element, but not namespaces inherited from a parent element

See Also:
Constant Field Values

ALL_NAMESPACES

static final int ALL_NAMESPACES
Copy all in-scope namespaces

See Also:
Constant Field Values
Method Detail

getNodeKind

int getNodeKind()
Get the kind of node. This will be a value such as Type.ELEMENT or Type.ATTRIBUTE. There are seven kinds of node: documents, elements, attributes, text, comments, processing-instructions, and namespaces.

Returns:
an integer identifying the kind of node. These integer values are the same as those used in the DOM
Since:
8.4
See Also:
Type

isSameNodeInfo

boolean isSameNodeInfo(NodeInfo other)
Determine whether this is the same node as another node.

Note that two different NodeInfo instances can represent the same conceptual node. Therefore the "==" operator should not be used to test node identity. The equals() method should give the same result as isSameNodeInfo(), but since this rule was introduced late it might not apply to all implementations.

Note: a.isSameNodeInfo(b) if and only if generateId(a)==generateId(b).

This method has the same semantics as isSameNode() in DOM Level 3, but works on Saxon NodeInfo objects rather than DOM Node objects.

Parameters:
other - the node to be compared with this node
Returns:
true if this NodeInfo object and the supplied NodeInfo object represent the same node in the tree.

equals

boolean equals(Object other)
The equals() method compares nodes for identity. It is defined to give the same result as isSameNodeInfo().

Overrides:
equals in class Object
Parameters:
other - the node to be compared with this node
Returns:
true if this NodeInfo object and the supplied NodeInfo object represent the same node in the tree.
Since:
8.7 Previously, the effect of the equals() method was not defined. Callers should therefore be aware that third party implementations of the NodeInfo interface may not implement the correct semantics. It is safer to use isSameNodeInfo() for this reason. The equals() method has been defined because it is useful in contexts such as a Java Set or HashMap.

hashCode

int hashCode()
The hashCode() method obeys the contract for hashCode(): that is, if two objects are equal (represent the same node) then they must have the same hashCode()

Overrides:
hashCode in class Object
Since:
8.7 Previously, the effect of the equals() and hashCode() methods was not defined. Callers should therefore be aware that third party implementations of the NodeInfo interface may not implement the correct semantics.

getSystemId

String getSystemId()
Get the System ID for the node. Note this is not the same as the base URI: the base URI can be modified by xml:base, but the system ID cannot. The base URI is used primarily for resolving relative URIs within the content of the document. The system ID is used primarily in conjunction with a line number, for identifying the location of elements within the source XML, in particular when errors are found. For a document node, the System ID represents the value of the document-uri property as defined in the XDM data model.

Specified by:
getSystemId in interface Source
Returns:
the System Identifier of the entity in the source document containing the node, or null if not known or not applicable.
Since:
8.4

getBaseURI

String getBaseURI()
Get the Base URI for the node, that is, the URI used for resolving a relative URI contained in the node. This will be the same as the System ID unless xml:base has been used. Where the node does not have a base URI of its own, the base URI of its parent node is returned.

Returns:
the base URI of the node. This may be null if the base URI is unknown.
Since:
8.4

getLineNumber

int getLineNumber()
Get line number. Line numbers are not maintained by default, except for stylesheets and schema documents. Line numbering can be requested using the -l option on the command line, or by setting options on the TransformerFactory or the Configuration before the source document is built.

The granularity of line numbering is normally the element level: for other nodes such as text nodes and attributes, the line number of the parent element will normally be returned.

In the case of a tree constructed by taking input from a SAX parser, the line number will reflect the SAX rules: that is, the line number of an element is the line number where the start tag ends. This may be a little confusing where elements have many attributes spread over multiple lines, or where single attributes (as can easily happen with XSLT 2.0 stylesheets) occupy several lines.

In the case of a tree constructed by a stylesheet or query, the line number may reflect the line in the stylesheet or query that caused the node to be constructed.

The line number can be read from within an XPath expression using the Saxon extension function saxon:line-number()

Returns:
the line number of the node in its original source document; or -1 if not available
Since:
8.4

compareOrder

int compareOrder(NodeInfo other)
Determine the relative position of this node and another node, in document order.

The other node must always be in the same tree; the effect of calling this method when the two nodes are in different trees is undefined. To obtain a global ordering of nodes, the application should first compare the result of getDocumentNumber(), and only if the document number is the same should compareOrder() be called.

Parameters:
other - The other node, whose position is to be compared with this node
Returns:
-1 if this node precedes the other node, +1 if it follows the other node, or 0 if they are the same node. (In this case, isSameNode() will always return true, and the two nodes will produce the same result for generateId())
Since:
8.4

getStringValue

String getStringValue()
Return the string value of the node as defined in the XPath data model.

The interpretation of this depends on the type of node. For an element it is the accumulated character content of the element, including descendant elements.

This method returns the string value as if the node were untyped. Unlike the string value accessor in the XPath 2.0 data model, it does not report an error if the element has a complex type, instead it returns the concatenation of the descendant text nodes as it would if the element were untyped.

Specified by:
getStringValue in interface Item
Specified by:
getStringValue in interface ValueRepresentation
Returns:
the string value of the node
Since:
8.4
See Also:
Item.getStringValueCS()

getNameCode

int getNameCode()
Get name code. The name code is a coded form of the node name: two nodes with the same name code have the same namespace URI, the same local name, and the same prefix. By masking the name code with NamePool.FP_MASK, you get a fingerprint: two nodes with the same fingerprint have the same local name and namespace URI.

Returns:
an integer name code, which may be used to obtain the actual node name from the name pool. For unnamed nodes (text nodes, comments, document nodes, and namespace nodes for the default namespace), returns -1.
Since:
8.4
See Also:
allocate, getFingerprint

getFingerprint

int getFingerprint()
Get fingerprint. The fingerprint is a coded form of the expanded name of the node: two nodes with the same name code have the same namespace URI and the same local name. The fingerprint contains no information about the namespace prefix. For a name in the null namespace, the fingerprint is the same as the name code.

Returns:
an integer fingerprint; two nodes with the same fingerprint have the same expanded QName. For unnamed nodes (text nodes, comments, document nodes, and namespace nodes for the default namespace), returns -1.
Since:
8.4

getLocalPart

String getLocalPart()
Get the local part of the name of this node. This is the name after the ":" if any.

Returns:
the local part of the name. For an unnamed node, returns "". Unlike the DOM interface, this returns the full name in the case of a non-namespaced name.
Since:
8.4

getURI

String getURI()
Get the URI part of the name of this node. This is the URI corresponding to the prefix, or the URI of the default namespace if appropriate.

Returns:
The URI of the namespace of this node. For an unnamed node, or for an element or attribute that is not in a namespace, or for a processing instruction, returns an empty string.
Since:
8.4

getDisplayName

String getDisplayName()
Get the display name of this node, in the form of a lexical QName. For elements and attributes this is [prefix:]localname. For unnamed nodes, it is an empty string.

Returns:
The display name of this node. For a node with no name, returns an empty string.
Since:
8.4

getPrefix

String getPrefix()
Get the prefix of the name of the node. This is defined only for elements and attributes. If the node has no prefix, or for other kinds of node, returns a zero-length string.

Returns:
The prefix of the name of the node.
Since:
8.4

getConfiguration

Configuration getConfiguration()
Get the configuration used to build the tree containing this node.

Returns:
the Configuration
Since:
8.4

getNamePool

NamePool getNamePool()
Get the NamePool that holds the namecode for this node

Returns:
the namepool
Since:
8.4

getTypeAnnotation

int getTypeAnnotation()
Get the type annotation of this node, if any. The type annotation is represented as an integer; this is the fingerprint of the name of the type, as defined in the name pool. Anonymous types are given a system-defined name. The value of the type annotation can be used to retrieve the actual schema type definition using the method Configuration.getSchemaType(int).

The bit IS_DTD_TYPE (1<<30) will be set in the case of an attribute node if the type annotation is one of ID, IDREF, or IDREFS and this is derived from DTD rather than schema validation.

Returns:
the type annotation of the node, under the mask NamePool.FP_MASK, and optionally the bit setting IS_DTD_TYPE in the case of a DTD-derived ID or IDREF/S type (which is treated as untypedAtomic for the purposes of obtaining the typed value).

The result is undefined for nodes other than elements and attributes.

Since:
8.4

atomize

Value atomize()
              throws XPathException
Get the typed value. The result of this method will always be consistent with the method Item.getTypedValue(). However, this method is often more convenient and may be more efficient, especially in the common case where the value is expected to be a singleton.

Returns:
the typed value. This will either be a single AtomicValue or a Value whose items are atomic values.
Throws:
XPathException
Since:
8.5

getParent

NodeInfo getParent()
Get the NodeInfo object representing the parent of this node

Returns:
the parent of this node; null if this node has no parent
Since:
8.4

iterateAxis

AxisIterator iterateAxis(byte axisNumber)
Return an iteration over all the nodes reached by the given axis from this node

Parameters:
axisNumber - an integer identifying the axis; one of the constants defined in class Axis
Returns:
an AxisIterator that delivers the nodes reached by the axis in turn. The nodes are returned in axis order (document order for a forwards axis, reverse document order for a reverse axis).
Throws:
UnsupportedOperationException - if the namespace axis is requested and this axis is not supported for this implementation.
Since:
8.4
See Also:
Axis

iterateAxis

AxisIterator iterateAxis(byte axisNumber,
                         NodeTest nodeTest)
Return an iteration over all the nodes reached by the given axis from this node that match a given NodeTest

Parameters:
axisNumber - an integer identifying the axis; one of the constants defined in class Axis
nodeTest - A condition to be satisfied by the returned nodes; nodes that do not satisfy this condition are not included in the result
Returns:
an AxisIterator that delivers the nodes reached by the axis in turn. The nodes are returned in axis order (document order for a forwards axis, reverse document order for a reverse axis).
Throws:
UnsupportedOperationException - if the namespace axis is requested and this axis is not supported for this implementation.
Since:
8.4
See Also:
Axis

getAttributeValue

String getAttributeValue(int fingerprint)
Get the string value of a given attribute of this node

Parameters:
fingerprint - The fingerprint of the attribute name
Returns:
the attribute value if it exists, or null if it does not exist. Always returns null if this node is not an element.
Since:
8.4

getRoot

NodeInfo getRoot()
Get the root node of the tree containing this node

Returns:
the NodeInfo representing the top-level ancestor of this node. This will not necessarily be a document node. If this node has no parent, then the method returns this node.
Since:
8.4

getDocumentRoot

DocumentInfo getDocumentRoot()
Get the root node, if it is a document node.

Returns:
the DocumentInfo representing the containing document. If this node is part of a tree that does not have a document node as its root, returns null.
Since:
8.4

hasChildNodes

boolean hasChildNodes()
Determine whether the node has any children.

Note: the result is equivalent to
iterateAxis(Axis.CHILD).next() != null

Returns:
True if the node has one or more children
Since:
8.4

generateId

void generateId(FastStringBuffer buffer)
Construct a character string that uniquely identifies this node. Note: a.isSameNode(b) if and only if generateId(a)==generateId(b)

Parameters:
buffer - a buffer which will be updated to hold a string that uniquely identifies this node, across all documents.
Since:
8.7

Changed in Saxon 8.7 to generate the ID value in a client-supplied buffer


getDocumentNumber

int getDocumentNumber()
Get the document number of the document containing this node. For a free-standing orphan node, just return the hashcode.

Returns:
the document number of the document containing this node
Since:
8.4

copy

void copy(Receiver out,
          int whichNamespaces,
          boolean copyAnnotations,
          int locationId)
          throws XPathException
Copy this node to a given Receiver.

This method is primarily for internal use. It should not be considered a stable part of the Saxon API.

Parameters:
out - the Receiver to which the node should be copied
whichNamespaces - in the case of an element, controls which namespace nodes should be copied. Values are NO_NAMESPACES, LOCAL_NAMESPACES, ALL_NAMESPACES
copyAnnotations - indicates whether the type annotations of element and attribute nodes should be copied
locationId - If non-zero, identifies the location of the instruction that requested this copy. If zero, indicates that the location information for the original node is to be copied; in this case the Receiver must be a LocationCopier
Throws:
XPathException

getDeclaredNamespaces

int[] getDeclaredNamespaces(int[] buffer)
Get all namespace declarations and undeclarations defined on this element.

This method is intended primarily for internal use. User applications needing information about the namespace context of a node should use iterateAxis(Axis.NAMESPACE). (However, not all implementations support the namespace axis, whereas all implementations are required to support this method.)

Parameters:
buffer - If this is non-null, and the result array fits in this buffer, then the result may overwrite the contents of this array, to avoid the cost of allocating a new array on the heap.
Returns:
An array of integers representing the namespace declarations and undeclarations present on this element. For a node other than an element, return null. Otherwise, the returned array is a sequence of namespace codes, whose meaning may be interpreted by reference to the name pool. The top half word of each namespace code represents the prefix, the bottom half represents the URI. If the bottom half is zero, then this is a namespace undeclaration rather than a declaration. The XML namespace is never included in the list. If the supplied array is larger than required, then the first unused entry will be set to -1.

For a node other than an element, the method returns null.



Copyright (C) Michael H. Kay. All rights reserved.