org.apache.xpath.XPathContext Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* $Id: XPathContext.java 524809 2007-04-02 15:51:51Z zongaro $
*/
package org.apache.xpath;
import java.lang.reflect.Method;
import java.util.Stack;
import java.util.Vector;
import java.util.HashMap;
import java.util.Iterator;
import javax.xml.transform.ErrorListener;
import javax.xml.transform.SourceLocator;
import javax.xml.transform.TransformerException;
import javax.xml.transform.URIResolver;
import org.apache.xalan.extensions.ExpressionContext;
import org.apache.xalan.res.XSLMessages;
import org.apache.xml.dtm.Axis;
import org.apache.xml.dtm.DTM;
import org.apache.xml.dtm.DTMFilter;
import org.apache.xml.dtm.DTMIterator;
import org.apache.xml.dtm.DTMManager;
import org.apache.xml.dtm.DTMWSFilter;
import org.apache.xml.dtm.ref.sax2dtm.SAX2RTFDTM;
import org.apache.xml.utils.IntStack;
import org.apache.xml.utils.NodeVector;
import org.apache.xml.utils.ObjectStack;
import org.apache.xml.utils.PrefixResolver;
import org.apache.xml.utils.SAXSourceLocator;
import org.apache.xml.utils.XMLString;
import org.apache.xpath.axes.SubContextList;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.objects.DTMXRTreeFrag;
import org.apache.xpath.objects.XString;
import org.apache.xpath.res.XPATHErrorResources;
import org.xml.sax.XMLReader;
/**
* Default class for the runtime execution context for XPath.
*
* This class extends DTMManager but does not directly implement it.
* @xsl.usage advanced
*/
public class XPathContext extends DTMManager // implements ExpressionContext
{
IntStack m_last_pushed_rtfdtm=new IntStack();
/**
* Stack of cached "reusable" DTMs for Result Tree Fragments.
* This is a kluge to handle the problem of starting an RTF before
* the old one is complete.
*
* %REVIEW% I'm using a Vector rather than Stack so we can reuse
* the DTMs if the problem occurs multiple times. I'm not sure that's
* really a net win versus discarding the DTM and starting a new one...
* but the retained RTF DTM will have been tail-pruned so should be small.
*/
private Vector m_rtfdtm_stack=null;
/** Index of currently active RTF DTM in m_rtfdtm_stack */
private int m_which_rtfdtm=-1;
/**
* Most recent "reusable" DTM for Global Result Tree Fragments. No stack is
* required since we're never going to pop these.
*/
private SAX2RTFDTM m_global_rtfdtm=null;
/**
* HashMap of cached the DTMXRTreeFrag objects, which are identified by DTM IDs.
* The object are just wrappers for DTMs which are used in XRTreeFrag.
*/
private HashMap m_DTMXRTreeFrags = null;
/**
* state of the secure processing feature.
*/
private boolean m_isSecureProcessing = false;
/**
* Though XPathContext context extends
* the DTMManager, it really is a proxy for this object, which
* is the real DTMManager.
*/
protected DTMManager m_dtmManager = DTMManager.newInstance(
org.apache.xpath.objects.XMLStringFactoryImpl.getFactory());
/**
* Return the DTMManager object. Though XPathContext context extends
* the DTMManager, it really is a proxy for the real DTMManager. If a
* caller needs to make a lot of calls to the DTMManager, it is faster
* if it gets the real one from this function.
*/
public DTMManager getDTMManager()
{
return m_dtmManager;
}
/**
* Set the state of the secure processing feature
*/
public void setSecureProcessing(boolean flag)
{
m_isSecureProcessing = flag;
}
/**
* Return the state of the secure processing feature
*/
public boolean isSecureProcessing()
{
return m_isSecureProcessing;
}
/**
* Get an instance of a DTM, loaded with the content from the
* specified source. If the unique flag is true, a new instance will
* always be returned. Otherwise it is up to the DTMManager to return a
* new instance or an instance that it already created and may be being used
* by someone else.
* (I think more parameters will need to be added for error handling, and entity
* resolution).
*
* @param source the specification of the source object, which may be null,
* in which case it is assumed that node construction will take
* by some other means.
* @param unique true if the returned DTM must be unique, probably because it
* is going to be mutated.
* @param wsfilter Enables filtering of whitespace nodes, and may be null.
* @param incremental true if the construction should try and be incremental.
* @param doIndexing true if the caller considers it worth it to use
* indexing schemes.
*
* @return a non-null DTM reference.
*/
public DTM getDTM(javax.xml.transform.Source source, boolean unique,
DTMWSFilter wsfilter,
boolean incremental,
boolean doIndexing)
{
return m_dtmManager.getDTM(source, unique, wsfilter,
incremental, doIndexing);
}
/**
* Get an instance of a DTM that "owns" a node handle.
*
* @param nodeHandle the nodeHandle.
*
* @return a non-null DTM reference.
*/
public DTM getDTM(int nodeHandle)
{
return m_dtmManager.getDTM(nodeHandle);
}
/**
* Given a W3C DOM node, try and return a DTM handle.
* Note: calling this may be non-optimal.
*
* @param node Non-null reference to a DOM node.
*
* @return a valid DTM handle.
*/
public int getDTMHandleFromNode(org.w3c.dom.Node node)
{
return m_dtmManager.getDTMHandleFromNode(node);
}
//
//
/**
* %TBD% Doc
*/
public int getDTMIdentity(DTM dtm)
{
return m_dtmManager.getDTMIdentity(dtm);
}
//
/**
* Creates an empty DocumentFragment object.
* @return A new DocumentFragment handle.
*/
public DTM createDocumentFragment()
{
return m_dtmManager.createDocumentFragment();
}
//
/**
* Release a DTM either to a lru pool, or completely remove reference.
* DTMs without system IDs are always hard deleted.
* State: experimental.
*
* @param dtm The DTM to be released.
* @param shouldHardDelete True if the DTM should be removed no matter what.
* @return true if the DTM was removed, false if it was put back in a lru pool.
*/
public boolean release(DTM dtm, boolean shouldHardDelete)
{
// %REVIEW% If it's a DTM which may contain multiple Result Tree
// Fragments, we can't discard it unless we know not only that it
// is empty, but that the XPathContext itself is going away. So do
// _not_ accept the request. (May want to do it as part of
// reset(), though.)
if(m_rtfdtm_stack!=null && m_rtfdtm_stack.contains(dtm))
{
return false;
}
return m_dtmManager.release(dtm, shouldHardDelete);
}
/**
* Create a new DTMIterator based on an XPath
* UnionExpr.
*
* @param xpathCompiler ??? Somehow we need to pass in a subpart of the
* expression. I hate to do this with strings, since the larger expression
* has already been parsed.
*
* @param pos The position in the expression.
* @return The newly created DTMIterator.
*/
public DTMIterator createDTMIterator(Object xpathCompiler, int pos)
{
return m_dtmManager.createDTMIterator(xpathCompiler, pos);
}
//
/**
* Create a new DTMIterator based on an XPath
* UnionExpr.
*
* @param xpathString Must be a valid string expressing a
* UnionExpr.
*
* @param presolver An object that can resolve prefixes to namespace URLs.
*
* @return The newly created DTMIterator.
*/
public DTMIterator createDTMIterator(String xpathString,
PrefixResolver presolver)
{
return m_dtmManager.createDTMIterator(xpathString, presolver);
}
//
/**
* Create a new DTMIterator based only on a whatToShow and
* a DTMFilter. The traversal semantics are defined as the descendant
* access.
*
* @param whatToShow This flag specifies which node types may appear in
* the logical view of the tree presented by the iterator. See the
* description of NodeFilter for the set of possible
* SHOW_ values.These flags can be combined using
* OR.
* @param filter The NodeFilter to be used with this
* TreeWalker, or null to indicate no filter.
* @param entityReferenceExpansion The value of this flag determines
* whether entity reference nodes are expanded.
*
* @return The newly created NodeIterator.
*/
public DTMIterator createDTMIterator(int whatToShow,
DTMFilter filter, boolean entityReferenceExpansion)
{
return m_dtmManager.createDTMIterator(whatToShow, filter, entityReferenceExpansion);
}
/**
* Create a new DTMIterator that holds exactly one node.
*
* @param node The node handle that the DTMIterator will iterate to.
*
* @return The newly created DTMIterator.
*/
public DTMIterator createDTMIterator(int node)
{
// DescendantIterator iter = new DescendantIterator();
DTMIterator iter = new org.apache.xpath.axes.OneStepIteratorForward(Axis.SELF);
iter.setRoot(node, this);
return iter;
// return m_dtmManager.createDTMIterator(node);
}
/**
* Create an XPathContext instance. This is equivalent to calling
* the {@link #XPathContext(boolean)} constructor with the value
* true.
*/
public XPathContext() {
this(true);
}
/**
* Create an XPathContext instance.
* @param recursiveVarContext A boolean value indicating whether
* the XPath context needs to support pushing of scopes for
* variable resolution
*/
public XPathContext(boolean recursiveVarContext) {
m_prefixResolvers.push(null);
m_currentNodes.push(DTM.NULL);
m_currentExpressionNodes.push(DTM.NULL);
m_saxLocations.push(null);
m_variableStacks = recursiveVarContext ? new VariableStack()
: new VariableStack(1);
}
/**
* Create an XPathContext instance. This is equivalent to calling the
* constructor {@link #XPathContext(java.lang.Object,boolean)} with the
* value of the second parameter set to true.
* @param owner Value that can be retrieved via the getOwnerObject() method.
* @see #getOwnerObject
*/
public XPathContext(Object owner)
{
this(owner, true);
}
/**
* Create an XPathContext instance.
* @param owner Value that can be retrieved via the getOwnerObject() method.
* @see #getOwnerObject
* @param recursiveVarContext A boolean value indicating whether
* the XPath context needs to support pushing of scopes for
* variable resolution
*/
public XPathContext(Object owner, boolean recursiveVarContext) {
this(recursiveVarContext);
m_owner = owner;
try {
m_ownerGetErrorListener = m_owner.getClass().getMethod("getErrorListener", new Class[] {});
}
catch (NoSuchMethodException nsme) {}
}
/**
* Reset for new run.
*/
public void reset()
{
releaseDTMXRTreeFrags();
// These couldn't be disposed of earlier (see comments in release()); zap them now.
if(m_rtfdtm_stack!=null)
for (java.util.Enumeration e = m_rtfdtm_stack.elements() ; e.hasMoreElements() ;)
m_dtmManager.release((DTM)e.nextElement(), true);
m_rtfdtm_stack=null; // drop our references too
m_which_rtfdtm=-1;
if(m_global_rtfdtm!=null)
m_dtmManager.release(m_global_rtfdtm,true);
m_global_rtfdtm=null;
m_dtmManager = DTMManager.newInstance(
org.apache.xpath.objects.XMLStringFactoryImpl.getFactory());
m_saxLocations.removeAllElements();
m_axesIteratorStack.removeAllElements();
m_contextNodeLists.removeAllElements();
m_currentExpressionNodes.removeAllElements();
m_currentNodes.removeAllElements();
m_iteratorRoots.RemoveAllNoClear();
m_predicatePos.removeAllElements();
m_predicateRoots.RemoveAllNoClear();
m_prefixResolvers.removeAllElements();
m_prefixResolvers.push(null);
m_currentNodes.push(DTM.NULL);
m_currentExpressionNodes.push(DTM.NULL);
m_saxLocations.push(null);
}
/** The current stylesheet locator. */
ObjectStack m_saxLocations = new ObjectStack(RECURSIONLIMIT);
/**
* Set the current locater in the stylesheet.
*
* @param location The location within the stylesheet.
*/
public void setSAXLocator(SourceLocator location)
{
m_saxLocations.setTop(location);
}
/**
* Set the current locater in the stylesheet.
*
* @param location The location within the stylesheet.
*/
public void pushSAXLocator(SourceLocator location)
{
m_saxLocations.push(location);
}
/**
* Push a slot on the locations stack so that setSAXLocator can be
* repeatedly called.
*
*/
public void pushSAXLocatorNull()
{
m_saxLocations.push(null);
}
/**
* Pop the current locater.
*/
public void popSAXLocator()
{
m_saxLocations.pop();
}
/**
* Get the current locater in the stylesheet.
*
* @return The location within the stylesheet, or null if not known.
*/
public SourceLocator getSAXLocator()
{
return (SourceLocator) m_saxLocations.peek();
}
/** The owner context of this XPathContext. In the case of XSLT, this will be a
* Transformer object.
*/
private Object m_owner;
/** The owner context of this XPathContext. In the case of XSLT, this will be a
* Transformer object.
*/
private Method m_ownerGetErrorListener;
/**
* Get the "owner" context of this context, which should be,
* in the case of XSLT, the Transformer object. This is needed
* so that XSLT functions can get the Transformer.
* @return The owner object passed into the constructor, or null.
*/
public Object getOwnerObject()
{
return m_owner;
}
// ================ VarStack ===================
/**
* The stack of Variable stacks. A VariableStack will be
* pushed onto this stack for each template invocation.
*/
private VariableStack m_variableStacks;
/**
* Get the variable stack, which is in charge of variables and
* parameters.
*
* @return the variable stack, which should not be null.
*/
public final VariableStack getVarStack()
{
return m_variableStacks;
}
/**
* Get the variable stack, which is in charge of variables and
* parameters.
*
* @param varStack non-null reference to the variable stack.
*/
public final void setVarStack(VariableStack varStack)
{
m_variableStacks = varStack;
}
// ================ SourceTreeManager ===================
/** The source tree manager, which associates Source objects to source
* tree nodes. */
private SourceTreeManager m_sourceTreeManager = new SourceTreeManager();
/**
* Get the SourceTreeManager associated with this execution context.
*
* @return the SourceTreeManager associated with this execution context.
*/
public final SourceTreeManager getSourceTreeManager()
{
return m_sourceTreeManager;
}
/**
* Set the SourceTreeManager associated with this execution context.
*
* @param mgr the SourceTreeManager to be associated with this
* execution context.
*/
public void setSourceTreeManager(SourceTreeManager mgr)
{
m_sourceTreeManager = mgr;
}
// =================================================
/** The ErrorListener where errors and warnings are to be reported. */
private ErrorListener m_errorListener;
/** A default ErrorListener in case our m_errorListener was not specified and our
* owner either does not have an ErrorListener or has a null one.
*/
private ErrorListener m_defaultErrorListener;
/**
* Get the ErrorListener where errors and warnings are to be reported.
*
* @return A non-null ErrorListener reference.
*/
public final ErrorListener getErrorListener()
{
if (null != m_errorListener)
return m_errorListener;
ErrorListener retval = null;
try {
if (null != m_ownerGetErrorListener)
retval = (ErrorListener) m_ownerGetErrorListener.invoke(m_owner, new Object[] {});
}
catch (Exception e) {}
if (null == retval)
{
if (null == m_defaultErrorListener)
m_defaultErrorListener = new org.apache.xml.utils.DefaultErrorHandler();
retval = m_defaultErrorListener;
}
return retval;
}
/**
* Set the ErrorListener where errors and warnings are to be reported.
*
* @param listener A non-null ErrorListener reference.
*/
public void setErrorListener(ErrorListener listener) throws IllegalArgumentException
{
if (listener == null)
throw new IllegalArgumentException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_NULL_ERROR_HANDLER, null)); //"Null error handler");
m_errorListener = listener;
}
// =================================================
/** The TrAX URI Resolver for resolving URIs from the document(...)
* function to source tree nodes. */
private URIResolver m_uriResolver;
/**
* Get the URIResolver associated with this execution context.
*
* @return a URI resolver, which may be null.
*/
public final URIResolver getURIResolver()
{
return m_uriResolver;
}
/**
* Set the URIResolver associated with this execution context.
*
* @param resolver the URIResolver to be associated with this
* execution context, may be null to clear an already set resolver.
*/
public void setURIResolver(URIResolver resolver)
{
m_uriResolver = resolver;
}
// =================================================
/** The reader of the primary source tree. */
public XMLReader m_primaryReader;
/**
* Get primary XMLReader associated with this execution context.
*
* @return The reader of the primary source tree.
*/
public final XMLReader getPrimaryReader()
{
return m_primaryReader;
}
/**
* Set primary XMLReader associated with this execution context.
*
* @param reader The reader of the primary source tree.
*/
public void setPrimaryReader(XMLReader reader)
{
m_primaryReader = reader;
}
// =================================================
/** Misnamed string manager for XPath messages. */
// private static XSLMessages m_XSLMessages = new XSLMessages();
/**
* Tell the user of an assertion error, and probably throw an
* exception.
*
* @param b If false, a TransformerException will be thrown.
* @param msg The assertion message, which should be informative.
*
* @throws javax.xml.transform.TransformerException if b is false.
*/
private void assertion(boolean b, String msg) throws javax.xml.transform.TransformerException
{
if (!b)
{
ErrorListener errorHandler = getErrorListener();
if (errorHandler != null)
{
errorHandler.fatalError(
new TransformerException(
XSLMessages.createMessage(
XPATHErrorResources.ER_INCORRECT_PROGRAMMER_ASSERTION,
new Object[]{ msg }), (SAXSourceLocator)this.getSAXLocator()));
}
}
}
//==========================================================
// SECTION: Execution context state tracking
//==========================================================
/**
* The current context node list.
*/
private Stack m_contextNodeLists = new Stack();
public Stack getContextNodeListsStack() { return m_contextNodeLists; }
public void setContextNodeListsStack(Stack s) { m_contextNodeLists = s; }
/**
* Get the current context node list.
*
* @return the current node list,
* also refered to here as a context node list .
*/
public final DTMIterator getContextNodeList()
{
if (m_contextNodeLists.size() > 0)
return (DTMIterator) m_contextNodeLists.peek();
else
return null;
}
/**
* Set the current context node list.
*
* @param nl the current node list,
* also refered to here as a context node list .
* @xsl.usage internal
*/
public final void pushContextNodeList(DTMIterator nl)
{
m_contextNodeLists.push(nl);
}
/**
* Pop the current context node list.
* @xsl.usage internal
*/
public final void popContextNodeList()
{
if(m_contextNodeLists.isEmpty())
System.err.println("Warning: popContextNodeList when stack is empty!");
else
m_contextNodeLists.pop();
}
/**
* The ammount to use for stacks that record information during the
* recursive execution.
*/
public static final int RECURSIONLIMIT = (1024*4);
/** The stack of current node objects.
* Not to be confused with the current node list. %REVIEW% Note that there
* are no bounds check and resize for this stack, so if it is blown, it's all
* over. */
private IntStack m_currentNodes = new IntStack(RECURSIONLIMIT);
// private NodeVector m_currentNodes = new NodeVector();
public IntStack getCurrentNodeStack() {return m_currentNodes; }
public void setCurrentNodeStack(IntStack nv) { m_currentNodes = nv; }
/**
* Get the current context node.
*
* @return the current node.
*/
public final int getCurrentNode()
{
return m_currentNodes.peek();
}
/**
* Set the current context node and expression node.
*
* @param cn the current node.
* @param en the sub-expression context node.
*/
public final void pushCurrentNodeAndExpression(int cn, int en)
{
m_currentNodes.push(cn);
m_currentExpressionNodes.push(cn);
}
/**
* Set the current context node.
*/
public final void popCurrentNodeAndExpression()
{
m_currentNodes.quickPop(1);
m_currentExpressionNodes.quickPop(1);
}
/**
* Push the current context node, expression node, and prefix resolver.
*
* @param cn the current node.
* @param en the sub-expression context node.
* @param nc the namespace context (prefix resolver.
*/
public final void pushExpressionState(int cn, int en, PrefixResolver nc)
{
m_currentNodes.push(cn);
m_currentExpressionNodes.push(cn);
m_prefixResolvers.push(nc);
}
/**
* Pop the current context node, expression node, and prefix resolver.
*/
public final void popExpressionState()
{
m_currentNodes.quickPop(1);
m_currentExpressionNodes.quickPop(1);
m_prefixResolvers.pop();
}
/**
* Set the current context node.
*
* @param n the current node.
*/
public final void pushCurrentNode(int n)
{
m_currentNodes.push(n);
}
/**
* Pop the current context node.
*/
public final void popCurrentNode()
{
m_currentNodes.quickPop(1);
}
/**
* Set the current predicate root.
*/
public final void pushPredicateRoot(int n)
{
m_predicateRoots.push(n);
}
/**
* Pop the current predicate root.
*/
public final void popPredicateRoot()
{
m_predicateRoots.popQuick();
}
/**
* Get the current predicate root.
*/
public final int getPredicateRoot()
{
return m_predicateRoots.peepOrNull();
}
/**
* Set the current location path iterator root.
*/
public final void pushIteratorRoot(int n)
{
m_iteratorRoots.push(n);
}
/**
* Pop the current location path iterator root.
*/
public final void popIteratorRoot()
{
m_iteratorRoots.popQuick();
}
/**
* Get the current location path iterator root.
*/
public final int getIteratorRoot()
{
return m_iteratorRoots.peepOrNull();
}
/** A stack of the current sub-expression nodes. */
private NodeVector m_iteratorRoots = new NodeVector();
/** A stack of the current sub-expression nodes. */
private NodeVector m_predicateRoots = new NodeVector();
/** A stack of the current sub-expression nodes. */
private IntStack m_currentExpressionNodes = new IntStack(RECURSIONLIMIT);
public IntStack getCurrentExpressionNodeStack() { return m_currentExpressionNodes; }
public void setCurrentExpressionNodeStack(IntStack nv) { m_currentExpressionNodes = nv; }
private IntStack m_predicatePos = new IntStack();
public final int getPredicatePos()
{
return m_predicatePos.peek();
}
public final void pushPredicatePos(int n)
{
m_predicatePos.push(n);
}
public final void popPredicatePos()
{
m_predicatePos.pop();
}
/**
* Get the current node that is the expression's context (i.e. for current() support).
*
* @return The current sub-expression node.
*/
public final int getCurrentExpressionNode()
{
return m_currentExpressionNodes.peek();
}
/**
* Set the current node that is the expression's context (i.e. for current() support).
*
* @param n The sub-expression node to be current.
*/
public final void pushCurrentExpressionNode(int n)
{
m_currentExpressionNodes.push(n);
}
/**
* Pop the current node that is the expression's context
* (i.e. for current() support).
*/
public final void popCurrentExpressionNode()
{
m_currentExpressionNodes.quickPop(1);
}
private ObjectStack m_prefixResolvers
= new ObjectStack(RECURSIONLIMIT);
/**
* Get the current namespace context for the xpath.
*
* @return the current prefix resolver for resolving prefixes to
* namespace URLs.
*/
public final PrefixResolver getNamespaceContext()
{
return (PrefixResolver) m_prefixResolvers.peek();
}
/**
* Get the current namespace context for the xpath.
*
* @param pr the prefix resolver to be used for resolving prefixes to
* namespace URLs.
*/
public final void setNamespaceContext(PrefixResolver pr)
{
m_prefixResolvers.setTop(pr);
}
/**
* Push a current namespace context for the xpath.
*
* @param pr the prefix resolver to be used for resolving prefixes to
* namespace URLs.
*/
public final void pushNamespaceContext(PrefixResolver pr)
{
m_prefixResolvers.push(pr);
}
/**
* Just increment the namespace contest stack, so that setNamespaceContext
* can be used on the slot.
*/
public final void pushNamespaceContextNull()
{
m_prefixResolvers.push(null);
}
/**
* Pop the current namespace context for the xpath.
*/
public final void popNamespaceContext()
{
m_prefixResolvers.pop();
}
//==========================================================
// SECTION: Current TreeWalker contexts (for internal use)
//==========================================================
/**
* Stack of AxesIterators.
*/
private Stack m_axesIteratorStack = new Stack();
public Stack getAxesIteratorStackStacks() { return m_axesIteratorStack; }
public void setAxesIteratorStackStacks(Stack s) { m_axesIteratorStack = s; }
/**
* Push a TreeWalker on the stack.
*
* @param iter A sub-context AxesWalker.
* @xsl.usage internal
*/
public final void pushSubContextList(SubContextList iter)
{
m_axesIteratorStack.push(iter);
}
/**
* Pop the last pushed axes iterator.
* @xsl.usage internal
*/
public final void popSubContextList()
{
m_axesIteratorStack.pop();
}
/**
* Get the current axes iterator, or return null if none.
*
* @return the sub-context node list.
* @xsl.usage internal
*/
public SubContextList getSubContextList()
{
return m_axesIteratorStack.isEmpty()
? null : (SubContextList) m_axesIteratorStack.peek();
}
/**
* Get the current node list
* as defined by the XSLT spec.
*
* @return the current node list.
* @xsl.usage internal
*/
public org.apache.xpath.axes.SubContextList getCurrentNodeList()
{
return m_axesIteratorStack.isEmpty()
? null : (SubContextList) m_axesIteratorStack.elementAt(0);
}
//==========================================================
// SECTION: Implementation of ExpressionContext interface
//==========================================================
/**
* Get the current context node.
* @return The current context node.
*/
public final int getContextNode()
{
return this.getCurrentNode();
}
/**
* Get the current context node list.
* @return An iterator for the current context list, as
* defined in XSLT.
*/
public final DTMIterator getContextNodes()
{
try
{
DTMIterator cnl = getContextNodeList();
if (null != cnl)
return cnl.cloneWithReset();
else
return null; // for now... this might ought to be an empty iterator.
}
catch (CloneNotSupportedException cnse)
{
return null; // error reporting?
}
}
XPathExpressionContext expressionContext = new XPathExpressionContext();
/**
* The the expression context for extensions for this context.
*
* @return An object that implements the ExpressionContext.
*/
public ExpressionContext getExpressionContext()
{
return expressionContext;
}
public class XPathExpressionContext implements ExpressionContext
{
/**
* Return the XPathContext associated with this XPathExpressionContext.
* Extensions should use this judiciously and only when special processing
* requirements cannot be met another way. Consider requesting an enhancement
* to the ExpressionContext interface to avoid having to call this method.
* @return the XPathContext associated with this XPathExpressionContext.
*/
public XPathContext getXPathContext()
{
return XPathContext.this;
}
/**
* Return the DTMManager object. Though XPathContext context extends
* the DTMManager, it really is a proxy for the real DTMManager. If a
* caller needs to make a lot of calls to the DTMManager, it is faster
* if it gets the real one from this function.
*/
public DTMManager getDTMManager()
{
return m_dtmManager;
}
/**
* Get the current context node.
* @return The current context node.
*/
public org.w3c.dom.Node getContextNode()
{
int context = getCurrentNode();
return getDTM(context).getNode(context);
}
/**
* Get the current context node list.
* @return An iterator for the current context list, as
* defined in XSLT.
*/
public org.w3c.dom.traversal.NodeIterator getContextNodes()
{
return new org.apache.xml.dtm.ref.DTMNodeIterator(getContextNodeList());
}
/**
* Get the error listener.
* @return The registered error listener.
*/
public ErrorListener getErrorListener()
{
return XPathContext.this.getErrorListener();
}
/**
* Get the value of a node as a number.
* @param n Node to be converted to a number. May be null.
* @return value of n as a number.
*/
public double toNumber(org.w3c.dom.Node n)
{
// %REVIEW% You can't get much uglier than this...
int nodeHandle = getDTMHandleFromNode(n);
DTM dtm = getDTM(nodeHandle);
XString xobj = (XString)dtm.getStringValue(nodeHandle);
return xobj.num();
}
/**
* Get the value of a node as a string.
* @param n Node to be converted to a string. May be null.
* @return value of n as a string, or an empty string if n is null.
*/
public String toString(org.w3c.dom.Node n)
{
// %REVIEW% You can't get much uglier than this...
int nodeHandle = getDTMHandleFromNode(n);
DTM dtm = getDTM(nodeHandle);
XMLString strVal = dtm.getStringValue(nodeHandle);
return strVal.toString();
}
/**
* Get a variable based on it's qualified name.
* @param qname The qualified name of the variable.
* @return The evaluated value of the variable.
* @throws javax.xml.transform.TransformerException
*/
public final XObject getVariableOrParam(org.apache.xml.utils.QName qname)
throws javax.xml.transform.TransformerException
{
return m_variableStacks.getVariableOrParam(XPathContext.this, qname);
}
}
/**
* Get a DTM to be used as a container for a global Result Tree
* Fragment. This will always be an instance of (derived from? equivalent to?)
* SAX2DTM, since each RTF is constructed by temporarily redirecting our SAX
* output to it. It may be a single DTM containing for multiple fragments,
* if the implementation supports that.
*
* Note: The distinction between this method and getRTFDTM() is that the latter
* allocates space from the dynamic variable stack (m_rtfdtm_stack), which may
* be pruned away again as the templates which defined those variables are exited.
* Global variables may be bound late (see XUnresolvedVariable), and never want to
* be discarded, hence we need to allocate them separately and don't actually need
* a stack to track them.
*
* @return a non-null DTM reference.
*/
public DTM getGlobalRTFDTM()
{
// We probably should _NOT_ be applying whitespace filtering at this stage!
//
// Some magic has been applied in DTMManagerDefault to recognize this set of options
// and generate an instance of DTM which can contain multiple documents
// (SAX2RTFDTM). Perhaps not the optimal way of achieving that result, but
// I didn't want to change the manager API at this time, or expose
// too many dependencies on its internals. (Ideally, I'd like to move
// isTreeIncomplete all the way up to DTM, so we wouldn't need to explicitly
// specify the subclass here.)
// If it doesn't exist, or if the one already existing is in the middle of
// being constructed, we need to obtain a new DTM to write into. I'm not sure
// the latter will ever arise, but I'd rather be just a bit paranoid..
if( m_global_rtfdtm==null || m_global_rtfdtm.isTreeIncomplete() )
{
m_global_rtfdtm=(SAX2RTFDTM)m_dtmManager.getDTM(null,true,null,false,false);
}
return m_global_rtfdtm;
}
/**
* Get a DTM to be used as a container for a dynamic Result Tree
* Fragment. This will always be an instance of (derived from? equivalent to?)
* SAX2DTM, since each RTF is constructed by temporarily redirecting our SAX
* output to it. It may be a single DTM containing for multiple fragments,
* if the implementation supports that.
*
* @return a non-null DTM reference.
*/
public DTM getRTFDTM()
{
SAX2RTFDTM rtfdtm;
// We probably should _NOT_ be applying whitespace filtering at this stage!
//
// Some magic has been applied in DTMManagerDefault to recognize this set of options
// and generate an instance of DTM which can contain multiple documents
// (SAX2RTFDTM). Perhaps not the optimal way of achieving that result, but
// I didn't want to change the manager API at this time, or expose
// too many dependencies on its internals. (Ideally, I'd like to move
// isTreeIncomplete all the way up to DTM, so we wouldn't need to explicitly
// specify the subclass here.)
if(m_rtfdtm_stack==null)
{
m_rtfdtm_stack=new Vector();
rtfdtm=(SAX2RTFDTM)m_dtmManager.getDTM(null,true,null,false,false);
m_rtfdtm_stack.addElement(rtfdtm);
++m_which_rtfdtm;
}
else if(m_which_rtfdtm<0)
{
rtfdtm=(SAX2RTFDTM)m_rtfdtm_stack.elementAt(++m_which_rtfdtm);
}
else
{
rtfdtm=(SAX2RTFDTM)m_rtfdtm_stack.elementAt(m_which_rtfdtm);
// It might already be under construction -- the classic example would be
// an xsl:variable which uses xsl:call-template as part of its value. To
// handle this recursion, we have to start a new RTF DTM, pushing the old
// one onto a stack so we can return to it. This is not as uncommon a case
// as we might wish, unfortunately, as some folks insist on coding XSLT
// as if it were a procedural language...
if(rtfdtm.isTreeIncomplete())
{
if(++m_which_rtfdtm < m_rtfdtm_stack.size())
rtfdtm=(SAX2RTFDTM)m_rtfdtm_stack.elementAt(m_which_rtfdtm);
else
{
rtfdtm=(SAX2RTFDTM)m_dtmManager.getDTM(null,true,null,false,false);
m_rtfdtm_stack.addElement(rtfdtm);
}
}
}
return rtfdtm;
}
/** Push the RTFDTM's context mark, to allows discarding RTFs added after this
* point. (If it doesn't exist we don't push, since we might still be able to
* get away with not creating it. That requires that excessive pops be harmless.)
* */
public void pushRTFContext()
{
m_last_pushed_rtfdtm.push(m_which_rtfdtm);
if(null!=m_rtfdtm_stack)
((SAX2RTFDTM)(getRTFDTM())).pushRewindMark();
}
/** Pop the RTFDTM's context mark. This discards any RTFs added after the last
* mark was set.
*
* If there is no RTF DTM, there's nothing to pop so this
* becomes a no-op. If pushes were issued before this was called, we count on
* the fact that popRewindMark is defined such that overpopping just resets
* to empty.
*
* Complicating factor: We need to handle the case of popping back to a previous
* RTF DTM, if one of the weird produce-an-RTF-to-build-an-RTF cases arose.
* Basically: If pop says this DTM is now empty, then return to the previous
* if one exists, in whatever state we left it in. UGLY, but hopefully the
* situation which forces us to consider this will arise exceedingly rarely.
* */
public void popRTFContext()
{
int previous=m_last_pushed_rtfdtm.pop();
if(null==m_rtfdtm_stack)
return;
if(m_which_rtfdtm==previous)
{
if(previous>=0) // guard against none-active
{
boolean isEmpty=((SAX2RTFDTM)(m_rtfdtm_stack.elementAt(previous))).popRewindMark();
}
}
else while(m_which_rtfdtm!=previous)
{
// Empty each DTM before popping, so it's ready for reuse
// _DON'T_ pop the previous, since it's still open (which is why we
// stacked up more of these) and did not receive a mark.
boolean isEmpty=((SAX2RTFDTM)(m_rtfdtm_stack.elementAt(m_which_rtfdtm))).popRewindMark();
--m_which_rtfdtm;
}
}
/**
* Gets DTMXRTreeFrag object if one has already been created.
* Creates new DTMXRTreeFrag object and adds to m_DTMXRTreeFrags HashMap,
* otherwise.
* @param dtmIdentity
* @return DTMXRTreeFrag
*/
public DTMXRTreeFrag getDTMXRTreeFrag(int dtmIdentity){
if(m_DTMXRTreeFrags == null){
m_DTMXRTreeFrags = new HashMap();
}
if(m_DTMXRTreeFrags.containsKey(new Integer(dtmIdentity))){
return (DTMXRTreeFrag)m_DTMXRTreeFrags.get(new Integer(dtmIdentity));
}else{
final DTMXRTreeFrag frag = new DTMXRTreeFrag(dtmIdentity,this);
m_DTMXRTreeFrags.put(new Integer(dtmIdentity),frag);
return frag ;
}
}
/**
* Cleans DTMXRTreeFrag objects by removing references
* to DTM and XPathContext objects.
*/
private final void releaseDTMXRTreeFrags(){
if(m_DTMXRTreeFrags == null){
return;
}
final Iterator iter = (m_DTMXRTreeFrags.values()).iterator();
while(iter.hasNext()){
DTMXRTreeFrag frag = (DTMXRTreeFrag)iter.next();
frag.destruct();
iter.remove();
}
m_DTMXRTreeFrags = null;
}
}