net.sf.saxon.om

Class VirtualCopy

public class VirtualCopy extends Object implements NodeInfo, SourceLocator

This class represents a node that is a virtual copy of another node: that is, it behaves as a node that's the same as another node, but has different identity. Moreover, this class can create a virtual copy of a subtree, so that the parent of the virtual copy is null rather than being a virtual copy of the parent of the original. This means that none of the axes when applied to the virtual copy is allowed to stray outside the subtree. The virtual copy is implemented by means of a reference to the node of which it is a copy, but methods that are sensitive to node identity return a different result.
Nested Class Summary
protected classVirtualCopy.VirtualCopier
VirtualCopier implements the XPath axes as applied to a VirtualCopy node.
Field Summary
protected longdocumentNumber
protected NodeInfooriginal
protected VirtualCopyparent
protected NodeInforoot
protected StringsystemId
Constructor Summary
protected VirtualCopy(NodeInfo base)
Protected constructor: create a virtual copy of a node
Method Summary
Valueatomize()
Get the typed value.
intcompareOrder(NodeInfo other)
Determine the relative position of this node and another node, in document order.
voidcopy(Receiver out, int whichNamespaces, boolean copyAnnotations, int locationId)
Copy this node to a given outputter
booleanequals(Object other)
The equals() method compares nodes for identity.
voidgenerateId(FastStringBuffer buffer)
Get a character string that uniquely identifies this node.
StringgetAttributeValue(int fingerprint)
Get the value of a given attribute of this node
StringgetBaseURI()
Get the Base URI for the node, that is, the URI used for resolving a relative URI contained in the node.
intgetColumnNumber()
Get column number
ConfigurationgetConfiguration()
Get the configuration
int[]getDeclaredNamespaces(int[] buffer)
Get all namespace undeclarations and undeclarations defined on this element.
StringgetDisplayName()
Get the display name of this node.
longgetDocumentNumber()
Get the document number of the document containing this node.
DocumentInfogetDocumentRoot()
Get the root node, if it is a document node.
intgetFingerprint()
Get fingerprint.
intgetLineNumber()
Get line number
StringgetLocalPart()
Get the local part of the name of this node.
intgetNameCode()
Get name code.
NamePoolgetNamePool()
Get the NamePool that holds the namecode for this node
intgetNodeKind()
Get the kind of node.
NodeInfogetParent()
Get the NodeInfo object representing the parent of this node
StringgetPrefix()
Get the prefix of the name of the node.
StringgetPublicId()
Return the public identifier for the current document event.
NodeInfogetRoot()
Get the root node of the tree containing this node
StringgetStringValue()
Return the string value of the node.
CharSequencegetStringValueCS()
Get the value of the item as a CharSequence.
StringgetSystemId()
Get the System ID for the node.
intgetTypeAnnotation()
Get the type annotation of this node, if any.
SequenceIteratorgetTypedValue()
Get the typed value of the item
StringgetURI()
Get the URI part of the name of this node.
booleanhasChildNodes()
Determine whether the node has any children.
inthashCode()
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()
booleanisId()
Determine whether this node has the is-id property
booleanisIdref()
Determine whether this node has the is-idref property
booleanisNilled()
Determine whether the node has the is-nilled property
booleanisSameNodeInfo(NodeInfo other)
Determine whether this is the same node as another node.
AxisIteratoriterateAxis(byte axisNumber)
Return an iteration over all the nodes reached by the given axis from this node
AxisIteratoriterateAxis(byte axisNumber, NodeTest nodeTest)
Return an iteration over all the nodes reached by the given axis from this node that match a given NodeTest
protected VirtualCopy.VirtualCopiermakeCopier(AxisIterator axis, VirtualCopy newParent, NodeInfo root)
Create an iterator that makes and returns virtual copies of nodes on the original tree
static VirtualCopymakeVirtualCopy(NodeInfo original, NodeInfo root)
Public factory method: create a virtual copy of a node
voidsetDocumentNumber(long documentNumber)
Set the unique document number of the virtual document.
voidsetSystemId(String systemId)
Set the system identifier for this Source.
protected VirtualCopywrap(NodeInfo node)
Wrap a node in a VirtualCopy.

Field Detail

documentNumber

protected long documentNumber

original

protected NodeInfo original

parent

protected VirtualCopy parent

root

protected NodeInfo root

systemId

protected String systemId

Constructor Detail

VirtualCopy

protected VirtualCopy(NodeInfo base)
Protected constructor: create a virtual copy of a node

Parameters: base the node to be copied

Method Detail

atomize

public Value atomize()
Get the typed value. The result of this method will always be consistent with the method 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. If requireSingleton is set to true, the result will always be an AtomicValue. In other cases it may be a Value representing a sequence whose items are atomic values.

Since: 8.5

compareOrder

public int compareOrder(NodeInfo other)
Determine the relative position of this node and another node, in document order. The other node will always be in the same document.

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())

copy

public void copy(Receiver out, int whichNamespaces, boolean copyAnnotations, int locationId)
Copy this node to a given outputter

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 Identifies the location of the instruction that requested this copy. Pass zero if no other information is available

Throws: net.sf.saxon.trans.XPathException

equals

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

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.

generateId

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

Parameters: buffer a buffer, to which will be appended a string that uniquely identifies this node, across all documents.

getAttributeValue

public String getAttributeValue(int fingerprint)
Get the 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 not

getBaseURI

public 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.

Returns: the base URI of the node

getColumnNumber

public int getColumnNumber()
Get column number

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

getConfiguration

public Configuration getConfiguration()
Get the configuration

getDeclaredNamespaces

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

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.

getDisplayName

public String getDisplayName()
Get the display name of this node. 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, return an empty string.

getDocumentNumber

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

getDocumentRoot

public 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, return null.

getFingerprint

public 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. A fingerprint of -1 should be returned for a node with no name.

Returns: an integer fingerprint; two nodes with the same fingerprint have the same expanded QName

getLineNumber

public int getLineNumber()
Get line number

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

getLocalPart

public 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.

getNameCode

public 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 &0xfffff, 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

See Also: allocate getFingerprint

getNamePool

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

Returns: the namepool

getNodeKind

public int getNodeKind()
Get the kind of node. This will be a value such as Type.ELEMENT or Type.ATTRIBUTE

Returns: an integer identifying the kind of node. These integer values are the same as those used in the DOM

See Also: Type

getParent

public 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

getPrefix

public 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, return a zero-length string.

Returns: The prefix of the name of the node.

getPublicId

public String getPublicId()
Return the public identifier for the current document event.

The return value is the public identifier of the document entity or of the external parsed entity in which the markup that triggered the event appears.

Returns: A string containing the public identifier, or null if none is available.

See Also: VirtualCopy

getRoot

public 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

getStringValue

public String getStringValue()
Return the string value of the node. 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.

Returns: the string value of the node

getStringValueCS

public CharSequence getStringValueCS()
Get the value of the item as a CharSequence. This is in some cases more efficient than the version of the method that returns a String.

getSystemId

public String getSystemId()
Get the System ID for the node.

Returns: the System Identifier of the entity in the source document containing the node, or null if not known. Note this is not the same as the base URI: the base URI can be modified by xml:base, but the system ID cannot.

getTypeAnnotation

public int getTypeAnnotation()
Get the type annotation of this node, if any.

Returns: the type annotation of the node.

See Also: Type

getTypedValue

public SequenceIterator getTypedValue()
Get the typed value of the item

Returns: the typed value of the item. In general this will be a sequence

Throws: net.sf.saxon.trans.XPathException where no typed value is available, e.g. for an element with complex content

getURI

public 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 a node with an empty prefix, return an empty string.

hasChildNodes

public boolean hasChildNodes()
Determine whether the node has any children.
Note: the result is equivalent to
getEnumeration(Axis.CHILD, AnyNodeTest.getInstance()).hasNext()

Returns: True if the node has one or more children

hashCode

public 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()

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.

isId

public boolean isId()
Determine whether this node has the is-id property

Returns: true if the node is an ID

isIdref

public boolean isIdref()
Determine whether this node has the is-idref property

Returns: true if the node is an IDREF or IDREFS element or attribute

isNilled

public boolean isNilled()
Determine whether the node has the is-nilled property

Returns: true if the node has the is-nilled property

isSameNodeInfo

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

iterateAxis

public 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 net.sf.saxon.om.Axis

Returns: an AxisIterator that scans the nodes reached by the axis in turn.

Throws: UnsupportedOperationException if the namespace axis is requested and this axis is not supported for this implementation.

See Also: Axis

iterateAxis

public 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 net.sf.saxon.om.Axis nodeTest A pattern to be matched by the returned nodes; nodes that do not match this pattern are not included in the result

Returns: an AxisIterator that scans the nodes reached by the axis in turn.

Throws: UnsupportedOperationException if the namespace axis is requested and this axis is not supported for this implementation.

See Also: Axis

makeCopier

protected VirtualCopy.VirtualCopier makeCopier(AxisIterator axis, VirtualCopy newParent, NodeInfo root)
Create an iterator that makes and returns virtual copies of nodes on the original tree

Parameters: axis the axis to be navigated newParent the parent of the nodes in the new virtual tree (may be null) root the root of the virtual tree

Returns: the iterator that does the copying

makeVirtualCopy

public static VirtualCopy makeVirtualCopy(NodeInfo original, NodeInfo root)
Public factory method: create a virtual copy of a node

Parameters: original the node to be copied root the root of the tree containing the node to be copied

Returns: the virtual copy. If the original was already a virtual copy, this will be a virtual copy of the real underlying node.

setDocumentNumber

public void setDocumentNumber(long documentNumber)
Set the unique document number of the virtual document. This method must be called to ensure that nodes in the virtual copy have unique node identifiers

Parameters: documentNumber the document number to be allocated. This can be obtained from the DocumentNumberAllocator which is accessible from the Configuration using getDocumentNumberAllocator

setSystemId

public void setSystemId(String systemId)
Set the system identifier for this Source.

The system identifier is optional if the source does not get its data from a URL, but it may still be useful to provide one. The application can use a system identifier, for example, to resolve relative URIs and to include in error messages and warnings.

Parameters: systemId The system identifier as a URL string.

wrap

protected VirtualCopy wrap(NodeInfo node)
Wrap a node in a VirtualCopy. This method is designed for subclassing

Parameters: node the node to be wrapped