Package net.sf.saxon.tree.wrapper

Class VirtualCopy

java.lang.Object
net.sf.saxon.tree.wrapper.VirtualCopy
All Implemented Interfaces:
Source, SourceLocator, ActiveSource, GroundedValue, Item, NodeInfo, Sequence, Location, Locator
Direct Known Subclasses:
SnapshotNode, VirtualUntypedCopy
public class VirtualCopy extends Object implements NodeInfo
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.

  • Field Details

  • Constructor Details

    • VirtualCopy

      protected VirtualCopy(NodeInfo base, NodeInfo root)
      Protected constructor: create a virtual copy of a node
      Parameters:
      base - the node to be copied
      root - the node in the source tree corresponding to the root of the virtual tree. This must be an ancestor of the base node

  • Method Details

    • makeVirtualCopy

      public static VirtualCopy makeVirtualCopy(NodeInfo original)
      Public factory method: create a parentless virtual tree as a copy of an existing node
      Parameters:
      original - 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.

    • wrap

      protected VirtualCopy wrap(NodeInfo node)
      Wrap a node within an existing VirtualCopy.
      Parameters:
      node - the node to be wrapped
      Returns:
      a virtual copy of the node

    • getOriginalNode

      public NodeInfo getOriginalNode()
      Get the original (wrapped) node
      Returns:
      the node of which this one is a virtual copy

    • getTreeInfo

      public VirtualTreeInfo getTreeInfo()
      Get information about the tree to which this NodeInfo belongs
      Specified by:
      getTreeInfo in interface NodeInfo
      Returns:
      the TreeInfo
      Since:
      9.7

    • setDropNamespaces

      public void setDropNamespaces(boolean drop)
      Say that namespaces in the virtual tree should not be copied from the underlying tree. The semantics follow the rules for xsl:copy-of with copy-namespaces="no": that is, the only namespaces that are retained are those explicitly used in element or attribute nodes.
      Parameters:
      drop - true if namespaces are to be dropped

    • getAllNamespaces

      public NamespaceMap getAllNamespaces()
      Description copied from interface: NodeInfo
      Get all the namespace bindings that are in-scope for this element.

      For an element return all the prefix-to-uri bindings that are in scope. This may include a binding to the default namespace (represented by a prefix of ""). The map does NOT include the implicit binding of the XML namespace. It will never include "undeclarations" - that is, the namespace URI will never be empty; the effect of an undeclaration is to remove a binding from the in-scope namespaces, not to add anything.

      For a node other than an element, returns null.

      Specified by:
      getAllNamespaces in interface NodeInfo
      Returns:
      the in-scope namespaces for an element, or null for any other kind of node.

    • 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. 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.
      Specified by:
      getFingerprint in interface NodeInfo
      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.
      Throws:
      UnsupportedOperationException - if this kind of node does not hold namepool fingerprints (specifically, if hasFingerprint() returns false).
      Since:
      8.4 (moved into FingerprintedNode at some stage; then back into NodeInfo at 9.8).

    • hasFingerprint

      public boolean hasFingerprint()
      Ask whether this NodeInfo implementation holds a fingerprint identifying the name of the node in the NamePool. If the answer is true, then the getFingerprint() method must return the fingerprint of the node. If the answer is false, then the getFingerprint() method should throw an UnsupportedOperationException. In the case of unnamed nodes such as text nodes, the result can be either true (in which case getFingerprint() should return -1) or false (in which case getFingerprint may throw an exception).
      Specified by:
      hasFingerprint in interface NodeInfo
      Returns:
      true if the implementation of this node provides fingerprints.
      Since:
      9.8; previously Saxon relied on using FingerprintedNode as a marker interface.

    • getNodeKind

      public int getNodeKind()
      Get the kind of node. This will be a value such as Type.ELEMENT or Type.ATTRIBUTE
      Specified by:
      getNodeKind in interface NodeInfo
      Returns:
      an integer identifying the kind of node. These integer values are the same as those used in the DOM
      See Also:

    • equals

      public boolean equals(Object 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.
      Specified by:
      equals in interface NodeInfo
      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.

    • 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()
      Specified by:
      hashCode in interface NodeInfo
      Overrides:
      hashCode in class Object

    • getSystemId

      public String getSystemId()
      Get the System ID for the node.
      Specified by:
      getSystemId in interface Location
      Specified by:
      getSystemId in interface Locator
      Specified by:
      getSystemId in interface NodeInfo
      Specified by:
      getSystemId in interface Source
      Specified by:
      getSystemId in interface SourceLocator
      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.

    • 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.
      Specified by:
      getBaseURI in interface NodeInfo
      Returns:
      the base URI of the node

    • getLineNumber

      public int getLineNumber()
      Get line number
      Specified by:
      getLineNumber in interface Location
      Specified by:
      getLineNumber in interface Locator
      Specified by:
      getLineNumber in interface NodeInfo
      Specified by:
      getLineNumber in interface SourceLocator
      Returns:
      the line number of the node in its original source document; or -1 if not available

    • getColumnNumber

      public int getColumnNumber()
      Get column number
      Specified by:
      getColumnNumber in interface Location
      Specified by:
      getColumnNumber in interface Locator
      Specified by:
      getColumnNumber in interface NodeInfo
      Specified by:
      getColumnNumber in interface SourceLocator
      Returns:
      the column number of the node in its original source document; or -1 if not available

    • saveLocation

      public Location saveLocation()
      Get an immutable copy of this Location object. By default Location objects may be mutable, so they should not be saved for later use. The result of this operation holds the same location information, but in an immutable form.
      Specified by:
      saveLocation in interface Location
      Returns:
      an immutable copy (which may be the original object, if it is already immutable)

    • 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.
      Specified by:
      compareOrder in interface NodeInfo
      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())

    • getUnicodeStringValue

      public UnicodeString getUnicodeStringValue()
      Get the string value of the item
      Specified by:
      getUnicodeStringValue in interface GroundedValue
      Specified by:
      getUnicodeStringValue in interface Item
      Returns:
      the string value of this node

    • getLocalPart

      public String getLocalPart()
      Get the local part of the name of this node. This is the name after the ":" if any.
      Specified by:
      getLocalPart in interface NodeInfo
      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.

    • getNamespaceUri

      public NamespaceUri getNamespaceUri()
      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.
      Specified by:
      getNamespaceUri in interface NodeInfo
      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.

    • 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.
      Specified by:
      getPrefix in interface NodeInfo
      Returns:
      The prefix of the name of the node.

    • 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.
      Specified by:
      getDisplayName in interface NodeInfo
      Returns:
      The display name of this node. For a node with no name, return an empty string.

    • getConfiguration

      public Configuration getConfiguration()
      Get the configuration
      Specified by:
      getConfiguration in interface NodeInfo
      Returns:
      the Configuration to which the tree belongs. The default implementation invokes getTreeInfo().getConfiguration().

    • getSchemaType

      public SchemaType getSchemaType()
      Get the type annotation of this node, if any. The type annotation is represented as SchemaType object.

      Types derived from a DTD are not reflected in the result of this method.

      Specified by:
      getSchemaType in interface NodeInfo
      Returns:
      For element and attribute nodes: the type annotation derived from schema validation (defaulting to xs:untyped and xs:untypedAtomic in the absence of schema validation). For comments, text nodes, processing instructions, and namespaces: null. For document nodes, either xs:untyped if the document has not been validated, or xs:anyType if it has.
      Since:
      9.4

    • getParent

      public NodeInfo getParent()
      Get the NodeInfo object representing the parent of this node
      Specified by:
      getParent in interface NodeInfo
      Returns:
      the parent of this node; null if this node has no parent

    • iterateAxis

      public AxisIterator iterateAxis(int axisNumber, NodePredicate nodeTest)
      Return an iteration over all the nodes reached by the given axis from this node that match a given NodeTest
      Specified by:
      iterateAxis in interface NodeInfo
      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:

    • getAttributeValue

      public String getAttributeValue(NamespaceUri uri, String local)
      Get the string value of a given attribute of this node
      Specified by:
      getAttributeValue in interface NodeInfo
      Parameters:
      uri - the namespace URI of the attribute name. Supply the empty string for an attribute that is in no namespace
      local - the local part 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.

    • getRoot

      public NodeInfo getRoot()
      Get the root node of the tree containing this node
      Specified by:
      getRoot in interface NodeInfo
      Returns:
      the NodeInfo representing the top-level ancestor of this node. This will not necessarily be a document node

    • hasChildNodes

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

      Note: the result is equivalent to getEnumeration(Axis.CHILD, AnyNodeTest.getInstance()).hasNext()

      Specified by:
      hasChildNodes in interface NodeInfo
      Returns:
      True if the node has one or more children

    • generateId

      public void generateId(StringBuilder buffer)
      Get a character string that uniquely identifies this node. Note: a.isSameNode(b) if and only if generateId(a)==generateId(b)
      Specified by:
      generateId in interface NodeInfo
      Parameters:
      buffer - a buffer, to which will be appended a string that uniquely identifies this node, across all documents.

    • copy

      public void copy(Receiver out, int copyOptions, Location locationId) throws XPathException
      Copy this node to a given outputter
      Specified by:
      copy in interface NodeInfo
      Parameters:
      out - the Receiver to which the node should be copied
      copyOptions - a selection of the options defined in CopyOptions
      locationId - Identifies the location of the instruction
      Throws:
      XPathException - if any downstream error occurs

    • getDeclaredNamespaces

      public NamespaceBinding[] getDeclaredNamespaces(NamespaceBinding[] buffer)
      Get all namespace declarations and undeclarations defined on this element.
      Specified by:
      getDeclaredNamespaces in interface NodeInfo
      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 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 NamespaceBinding objects. 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 null.

      For a VirtualCopy, the method needs to return all namespaces that are in scope for this element, because the virtual copy is assumed to contain copies of all the in-scope namespaces of the original.

    • 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.

      Specified by:
      setSystemId in interface NodeInfo
      Specified by:
      setSystemId in interface Source
      Parameters:
      systemId - The system identifier as a URL string.

    • atomize

      public AtomicSequence atomize() throws XPathException
      Get the typed value.
      Specified by:
      atomize in interface Item
      Specified by:
      atomize in interface NodeInfo
      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.
      Throws:
      XPathException - if the node has no typed value, for example if it is an element node with element-only content
      Since:
      8.5

    • isId

      public boolean isId()
      Determine whether this node has the is-id property
      Specified by:
      isId in interface NodeInfo
      Returns:
      true if the node is an ID

    • isIdref

      public boolean isIdref()
      Determine whether this node has the is-idref property
      Specified by:
      isIdref in interface NodeInfo
      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
      Specified by:
      isNilled in interface NodeInfo
      Returns:
      true if the node has the is-nilled property

    • 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.

      Specified by:
      getPublicId in interface Location
      Specified by:
      getPublicId in interface Locator
      Specified by:
      getPublicId in interface NodeInfo
      Specified by:
      getPublicId in interface SourceLocator
      Returns:
      A string containing the public identifier, or null if none is available.
      See Also:

    • isIncludedInCopy

      protected boolean isIncludedInCopy(NodeInfo sourceNode)
      Ask whether a node in the source tree is within the scope of this virtual copy
      Parameters:
      sourceNode - the node being tested
      Returns:
      true if the node is within the scope of the subtree

    • makeCopier

      protected VirtualCopy.VirtualCopier makeCopier(AxisIterator axis, VirtualCopy newParent, boolean testInclusion)
      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)
      testInclusion - if true, it is necessary to test whether nodes found in the source tree are included in the copy. If false, this test is unnecessary.
      Returns:
      the iterator that does the copying