File	Doc	Category	Size	Date	Package
FilterExprWalker.java	API Doc	Java SE 5 API	9745	Fri Aug 26 14:56:06 BST 2005	com.sun.org.apache.xpath.internal.axes

FilterExprWalker

• java.lang.Object
  • com.sun.org.apache.xpath.internal.Expression
    • com.sun.org.apache.xpath.internal.patterns.NodeTest
      • com.sun.org.apache.xpath.internal.axes.PredicatedNodeTest
        • com.sun.org.apache.xpath.internal.axes.AxesWalker

Fields Summary
private Expression	m_expr The contained expression. Should be non-null.
private transient XNodeSet	m_exprObj The result of executing m_expr. Needs to be deep cloned on clone op.
private boolean	m_mustHardReset
private boolean	m_canDetachNodeset

Constructors Summary
public FilterExprWalker(WalkingIterator locPathIterator) Construct a FilterExprWalker using a LocPathIterator. param locPathIterator non-null reference to the parent iterator. super(locPathIterator, Axis.FILTEREDLIST);

Methods Summary
public short	acceptNode(int n) This method needs to override AxesWalker.acceptNode because FilterExprWalkers don't need to, and shouldn't, do a node test. param n The node to check to see if it passes the filter or not. return a constant to determine whether the node is accepted, rejected, or skipped, as defined above . try { if (getPredicateCount() > 0) { countProximityPosition(0); if (!executePredicates(n, m_lpi.getXPathContext())) return DTMIterator.FILTER_SKIP; } return DTMIterator.FILTER_ACCEPT; } catch (javax.xml.transform.TransformerException se) { throw new RuntimeException(se.getMessage()); }
public void	callPredicateVisitors(com.sun.org.apache.xpath.internal.XPathVisitor visitor) This will traverse the heararchy, calling the visitor for each member. If the called visitor method returns false, the subtree should not be called. param owner The owner of the visitor, where that path may be rewritten if needed. param visitor The visitor whose appropriate method will be called. m_expr.callVisitors(new filterExprOwner(), visitor); super.callPredicateVisitors(visitor);
public java.lang.Object	clone() Get a cloned FilterExprWalker. return A new FilterExprWalker that can be used without mutating this one. throws CloneNotSupportedException FilterExprWalker clone = (FilterExprWalker) super.clone(); // clone.m_expr = (Expression)((Expression)m_expr).clone(); if (null != m_exprObj) clone.m_exprObj = (XNodeSet) m_exprObj.clone(); return clone;
public boolean	deepEquals(com.sun.org.apache.xpath.internal.Expression expr) see Expression#deepEquals(Expression) if (!super.deepEquals(expr)) return false; FilterExprWalker walker = (FilterExprWalker)expr; if(!m_expr.deepEquals(walker.m_expr)) return false; return true;
public void	detach() Detaches the walker from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state. super.detach(); if (m_canDetachNodeset) { m_exprObj.detach(); } m_exprObj = null;
public void	fixupVariables(java.util.Vector vars, int globalsSize) This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time. param vars List of QNames that correspond to variables. This list should be searched backwards for the first qualified name that corresponds to the variable reference qname. The position of the QName in the vector from the start of the vector will be its position in the stack frame (but variables above the globalsTop value will need to be offset to the current stack frame). super.fixupVariables(vars, globalsSize); m_expr.fixupVariables(vars, globalsSize);
public int	getAnalysisBits() Get the analysis bits for this walker, as defined in the WalkerFactory. return One of WalkerFactory#BIT_DESCENDANT, etc. if (null != m_expr && m_expr instanceof PathComponent) { return ((PathComponent) m_expr).getAnalysisBits(); } return WalkerFactory.BIT_FILTER;
public int	getAxis() Returns the axis being iterated, if it is known. return Axis.CHILD, etc., or -1 if the axis is not known or is of multiple types. return m_exprObj.getAxis();
public com.sun.org.apache.xpath.internal.Expression	getInnerExpression() Get the inner contained expression of this filter. return m_expr;
public int	getLastPos(com.sun.org.apache.xpath.internal.XPathContext xctxt) Get the index of the last node that can be itterated to. param xctxt XPath runtime context. return the index of the last node that can be itterated to. return m_exprObj.getLength();
public int	getNextNode() Moves the TreeWalker to the next visible node in document order relative to the current node, and returns the new node. If the current node has no next node, or if the search for nextNode attempts to step upward from the TreeWalker's root node, returns null , and retains the current node. return The new node, or null if the current node has no next node in the TreeWalker's logical view. if (null != m_exprObj) { int next = m_exprObj.nextNode(); return next; } else return DTM.NULL;
public void	init(com.sun.org.apache.xpath.internal.compiler.Compiler compiler, int opPos, int stepType) Init a FilterExprWalker. param compiler non-null reference to the Compiler that is constructing. param opPos positive opcode position for this step. param stepType The type of step. throws javax.xml.transform.TransformerException super.init(compiler, opPos, stepType); // Smooth over an anomily in the opcode map... switch (stepType) { case OpCodes.OP_FUNCTION : case OpCodes.OP_EXTFUNCTION : m_mustHardReset = true; case OpCodes.OP_GROUP : case OpCodes.OP_VARIABLE : m_expr = compiler.compile(opPos); m_expr.exprSetParent(this); //if((OpCodes.OP_FUNCTION == stepType) && (m_expr instanceof com.sun.org.apache.xalan.internal.templates.FuncKey)) if(m_expr instanceof com.sun.org.apache.xpath.internal.operations.Variable) { // hack/temp workaround m_canDetachNodeset = false; } break; default : m_expr = compiler.compile(opPos + 2); m_expr.exprSetParent(this); } // if(m_expr instanceof WalkingIterator) // { // WalkingIterator wi = (WalkingIterator)m_expr; // if(wi.getFirstWalker() instanceof FilterExprWalker) // { // FilterExprWalker fw = (FilterExprWalker)wi.getFirstWalker(); // if(null == fw.getNextWalker()) // { // m_expr = fw.m_expr; // m_expr.exprSetParent(this); // } // } // // }
public boolean	isDocOrdered() Returns true if all the nodes in the iteration well be returned in document order. Warning: This can only be called after setRoot has been called! return true as a default. return m_exprObj.isDocOrdered();
public void	setInnerExpression(com.sun.org.apache.xpath.internal.Expression expr) Set the inner contained expression of this filter. expr.exprSetParent(this); m_expr = expr;
public void	setRoot(int root) Set the root node of the TreeWalker. param root non-null reference to the root, or starting point of the query. super.setRoot(root); m_exprObj = FilterExprIteratorSimple.executeFilterExpr(root, m_lpi.getXPathContext(), m_lpi.getPrefixResolver(), m_lpi.getIsTopLevel(), m_lpi.m_stackFrame, m_expr);