Class Navigator

java.lang.Object
net.sf.saxon.om.Navigator

public final class Navigator extends Object
The Navigator class provides helper classes for navigating a tree, irrespective of its implementation
Author:
Michael H. Kay
  • Method Details

    • getAttributeValue

      public static String getAttributeValue(NodeInfo element, String uri, String localName)
      Get the string value of an attribute of a given element, given the URI and local part of the attribute name.
      Parameters:
      uri - The namespace URI. The null URI is represented as an empty string.
      localName - The local part of the name.
      Returns:
      the attribute value, or null if the attribute is not present
    • getBaseURI

      public static String getBaseURI(NodeInfo node)
      Helper method to get the base URI of an element or processing instruction node
    • sendNamespaceDeclarations

      public static void sendNamespaceDeclarations(NodeInfo node, Receiver out, boolean includeAncestors) throws XPathException
      Output all namespace nodes associated with this element. Does nothing if the node is not an element. This is a helper method to allow the method NodeInfo.sendNamespaceDeclarations(net.sf.saxon.event.Receiver, boolean) to be implemented if NodeInfo.getDeclaredNamespaces(int[]) is available.
      Parameters:
      out - The relevant outputter
      includeAncestors - True if namespaces declared on ancestor elements must be output
      Throws:
      XPathException
    • getPath

      public static String getPath(NodeInfo node)
      Get an absolute XPath expression that identifies a given node within its document
      Parameters:
      node - the node whose path is required. If null is supplied, an empty string is returned - this fact is used in making a recursive call for a parentless node.
      Returns:
      a path expression that can be used to retrieve the node
    • getNumberSimple

      public static int getNumberSimple(NodeInfo node, XPathContext context) throws XPathException
      Get simple node number. This is defined as one plus the number of previous siblings of the same node type and name. It is not accessible directly in XSL.
      Parameters:
      node - The node whose number is required
      context - Used for remembering previous result, for performance
      Returns:
      the node number, as defined above
      Throws:
      XPathException - if any error occurs
    • getNumberSingle

      public static int getNumberSingle(NodeInfo node, Pattern count, Pattern from, XPathContext context) throws XPathException
      Get node number (level="single"). If the current node matches the supplied pattern, the returned number is one plus the number of previous siblings that match the pattern. Otherwise, return the element number of the nearest ancestor that matches the supplied pattern.
      Parameters:
      node - the current node, the one whose node number is required
      count - Pattern that identifies which nodes should be counted. Default (null) is the element name if the current node is an element, or "node()" otherwise.
      from - Pattern that specifies where counting starts from. Default (null) is the root node. (This parameter does not seem useful but is included for the sake of XSLT conformance.)
      context - the dynamic context of the transformation, used if the patterns reference context values (e.g. variables)
      Returns:
      the node number established as follows: go to the nearest ancestor-or-self that matches the 'count' pattern and that is a descendant of the nearest ancestor that matches the 'from' pattern. Return one plus the nunber of preceding siblings of that ancestor that match the 'count' pattern. If there is no such ancestor, return 0.
      Throws:
      XPathException - when any error occurs in processing
    • getNumberAny

      public static int getNumberAny(Expression inst, NodeInfo node, Pattern count, Pattern from, XPathContext context, boolean hasVariablesInPatterns) throws XPathException
      Get node number (level="any"). Return one plus the number of previous nodes in the document that match the supplied pattern
      Parameters:
      inst - Identifies the xsl:number expression; this is relevant when the function is memoised to support repeated use of the same instruction to number multiple nodes
      node - The node being numbered
      count - Pattern that identifies which nodes should be counted. Default (null) is the element name if the current node is an element, or "node()" otherwise.
      from - Pattern that specifies where counting starts from. Default (null) is the root node. Only nodes after the first (most recent) node that matches the 'from' pattern are counted.
      context - The dynamic context for the transformation
      hasVariablesInPatterns - if the count or from patterns contain variables, then it's not safe to get the answer by adding one to the number of the most recent node that matches
      Returns:
      one plus the number of nodes that precede the current node, that match the count pattern, and that follow the first node that matches the from pattern if specified.
      Throws:
      XPathException
    • getNumberMulti

      public static List getNumberMulti(NodeInfo node, Pattern count, Pattern from, XPathContext context) throws XPathException
      Get node number (level="multiple"). Return a vector giving the hierarchic position of this node. See the XSLT spec for details.
      Parameters:
      node - The node to be numbered
      count - Pattern that identifies which nodes (ancestors and their previous siblings) should be counted. Default (null) is the element name if the current node is an element, or "node()" otherwise.
      from - Pattern that specifies where counting starts from. Default (null) is the root node. Only nodes below the first (most recent) node that matches the 'from' pattern are counted.
      context - The dynamic context for the transformation
      Returns:
      a vector containing for each ancestor-or-self that matches the count pattern and that is below the nearest node that matches the from pattern, an Integer which is one greater than the number of previous siblings that match the count pattern.
      Throws:
      XPathException
    • copy

      public static void copy(NodeInfo node, Receiver out, NamePool namePool, int whichNamespaces, boolean copyAnnotations, int locationId) throws XPathException
      Generic (model-independent) implementation of deep copy algorithm for nodes. This is available for use by any node implementations that choose to use it.
      Parameters:
      node - The node to be copied
      out - The receiver to which events will be sent
      namePool - Namepool holding the name codes (used only to resolve namespace codes)
      whichNamespaces - Indicates which namespace nodes for an element should be copied
      copyAnnotations - Indicates whether type annotations should be copied
      Throws:
      XPathException - on any failure reported by the Receiver
    • compareOrder

      public static int compareOrder(SiblingCountingNode first, SiblingCountingNode second)
      Generic (model-independent) method to determine the relative position of two node in document order. The nodes must be in the same tree.
      Parameters:
      first - The first node
      second - The second node, whose position is to be compared with the first 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())
    • appendSequentialKey

      public static void appendSequentialKey(SiblingCountingNode node, FastStringBuffer sb, boolean addDocNr)
      Get a character string that uniquely identifies this node and that collates nodes into document order
    • alphaKey

      public static String alphaKey(int value)
      Construct an alphabetic key from an positive integer; the key collates in the same sequence as the integer
      Parameters:
      value - The positive integer key value (negative values are treated as zero).
    • isWhite

      public static final boolean isWhite(CharSequence content)
      Deprecated.
      Determine if a string is all-whitespace
      Parameters:
      content - the string to be tested
      Returns:
      true if the supplied string contains no non-whitespace characters
    • isAncestorOrSelf

      public static boolean isAncestorOrSelf(NodeInfo a, NodeInfo d)
      Test if one node is an ancestor-or-self of another
      Parameters:
      a - the putative ancestor-or-self node
      d - the putative descendant node
      Returns:
      true if a is an ancestor-or-self of d
    • filteredSingleton

      public static AxisIterator filteredSingleton(NodeInfo node, NodeTest nodeTest)
      Create an iterator over a singleton node, if it exists and matches a nodetest; otherwise return an empty iterator
      Parameters:
      node - the singleton node, or null if the node does not exist
      nodeTest - the test to be applied
      Returns:
      an iterator over the node if it exists and matches the test.