Package net.sf.saxon.tree.util

Class Navigator

java.lang.Object
net.sf.saxon.tree.util.Navigator
public final class Navigator extends Object
The Navigator class provides helper classes for navigating a tree, irrespective of its implementation

  • Method Details

    • getAttributeValue

      public static String getAttributeValue(NodeInfo element, NamespaceUri 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:
      element - the element on which the required attribute appears
      uri - The namespace URI of the attribute name. The "no namespace" case is represented as an empty string.
      localName - The local part of the attribute name.
      Returns:
      the attribute value, or null if the attribute is not present
      Since:
      9.0

    • getInheritedAttributeValue

      public static String getInheritedAttributeValue(NodeInfo element, NamespaceUri uri, String localName)
      Get the string value of an inherited attribute of a given element, given the URI and local part of the attribute name. If the element does not have such an attribute, go up the ancestor axis to find such an attribute
      Parameters:
      element - the element where the search should start
      uri - The namespace URI of the attribute name. The "no namespace" case is represented as an empty string.
      localName - The local part of the attribute name.
      Returns:
      the attribute value, or null if the attribute is not present on any ancestor
      Since:
      9.9

    • getNodeName

      public static StructuredQName getNodeName(NodeInfo node)
      Helper method to get the name of a node as a structuredQName. Used from bytecode
      Parameters:
      node - the node
      Returns:
      the name of the node if it has a name, or null otherwise

    • getOutermostElement

      public static NodeInfo getOutermostElement(TreeInfo doc)
      Helper method to get the outermost element of a document, given the document node
      Parameters:
      doc - the document node at the root of the document
      Returns:
      the first element child of the document node, if there is one, else null. This is often referred to as the "root element" or "document element". No error is reported if the document node has multiple element children, which can happen in a document constructed using XSLT or XQuery.
      Since:
      9.3

    • getBaseURI

      public static String getBaseURI(NodeInfo node)
      Helper method to get the base URI of an element or processing instruction node
      Parameters:
      node - the node whose base URI is required
      Returns:
      the base URI of the node
      Since:
      8.7

    • getBaseURI

      public static String getBaseURI(NodeInfo node, Predicate<NodeInfo> isTopElementWithinEntity)
      Helper method to get the base URI of an element or processing instruction node
      Parameters:
      node - the node whose base URI is required
      isTopElementWithinEntity - a predicate applied to a node that can be tested to determine if the node is an element that originated as the outermost element within an external entity. If this is the case, the rules for determining the base URI are slightly different; in particular, any @xml:base attribute on such a node is interpreted relative to the system ID of the entity, not relative to the base URI of the parent node.
      Returns:
      the base URI of the node
      Since:
      9.9

    • 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

    • getPath

      public static String getPath(NodeInfo node, XPathContext context)
      Get an absolute XPath expression that identifies a given node within its document. The resulting path is intended for human readers, not for software evaluation. It uses lexical QNames (prefix:localname) for element and attribute names, with the original prefix as it appears in the source document. The sibling position of an element (a/b[2]) is included unless the node is a streamed node.
      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.
      context - the XPath dynamic evaluation context. May be null if no context is known
      Returns:
      a path expression that can be used to retrieve the node

    • getAbsolutePath

      public static AbsolutePath getAbsolutePath(NodeInfo node)
      Get the absolute path to a node
      Parameters:
      node - the node in question
      Returns:
      an object representing the path to the node

    • haveSameName

      public static boolean haveSameName(NodeInfo n1, NodeInfo n2)
      Ask whether two nodes have the same name
      Parameters:
      n1 - the first node
      n2 - the second node
      Returns:
      true if they have the same namespace and local part

    • getNumberSimple

      public static int getNumberSimple(NodeInfo node, XPathContext context)
      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. May be null.
      Returns:
      the node number, as defined above

    • 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 at or 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 - if any dynamic error occurs

    • getNumberMulti

      public static List<Long> 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 - if an error occurs

    • copy

      public static void copy(NodeInfo node, Receiver out, int copyOptions, Location 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
      copyOptions - Options for copying namespaces, type annotations, etc, as defined in CopyOptions
      locationId - The location of the instruction invoking the copy
      Throws:
      XPathException - on any failure reported by the Receiver
      IllegalArgumentException - if the node is an attribute or namespace node

    • copy

      public static void copy(NodeInfo node, Outputter out, int copyOptions, Location 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 outputter to which events will be sent
      copyOptions - Options for copying namespaces, type annotations, etc, as defined in CopyOptions
      locationId - The location of the instruction invoking the copy
      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 nodes 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())

    • comparePosition

      public static int comparePosition(NodeInfo first, NodeInfo 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:
      AxisInfo.PRECEDING if this node is on the preceding axis of the other node; AxisInfo.FOLLOWING if it is on the following axis; AxisInfo.ANCESTOR if the first node is an ancestor of the second; AxisInfo.DESCENDANT if the first is a descendant of the second; AxisInfo.SELF if they are the same node.
      Throws:
      UnsupportedOperationException - if either node is an attribute or namespace
      Since:
      9.5

    • appendSequentialKey

      public static void appendSequentialKey(SiblingCountingNode node, StringBuilder sb, boolean addDocNr)
      Get a character string that uniquely identifies this node and that collates nodes into document order
      Parameters:
      node - the node whose unique identifier is reuqired
      sb - a buffer to which the unique identifier will be appended
      addDocNr - true if a unique document number is to be included in the information

    • 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).
      Returns:
      the alphabetic key value

    • 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

    • nodeTestFromPredicate

      public static NodeTest nodeTestFromPredicate(NodePredicate predicate)
      Convert a Predicate<NodeInfo> (if necessary) to a NodeTest
      Parameters:
      predicate - a Node predicate
      Returns:
      a NodeTest

    • filteredSingleton

      public static AxisIterator filteredSingleton(NodeInfo node, NodePredicate 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.

    • getSiblingPosition

      public static int getSiblingPosition(NodeInfo node, NodeTest nodeTest, int max)
      Get the sibling position of a node: specifically, count how many preceding siblings of a node satisfy the nodetest.
      Parameters:
      node - the starting node, which is assumed to satisfy the node test
      nodeTest - the node test
      max - the maximum number of nodes to be counted
      Returns:
      the number of preceding siblings that satisfy the node test, plus one, unless the number exceeds max, in which case return some number greater than or equal to max.