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Serializer to write out XML, HTML etc. as a stream of characters from an input DOM or from input
SAX events.
/*
* 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: BasicTestIterator.java 469314 2006-10-30 23:31:59Z minchau $
*/
package org.apache.xpath.axes;
import org.apache.xml.dtm.DTM;
import org.apache.xml.dtm.DTMFilter;
import org.apache.xml.dtm.DTMIterator;
import org.apache.xml.utils.PrefixResolver;
import org.apache.xpath.compiler.Compiler;
import org.apache.xpath.compiler.OpMap;
/**
* Base for iterators that handle predicates. Does the basic next
* node logic, so all the derived iterator has to do is get the
* next node.
*/
public abstract class BasicTestIterator extends LocPathIterator
{
static final long serialVersionUID = 3505378079378096623L;
/**
* Create a LocPathIterator object.
*
* @param nscontext The namespace context for this iterator,
* should be OK if null.
*/
protected BasicTestIterator()
{
}
/**
* Create a LocPathIterator object.
*
* @param nscontext The namespace context for this iterator,
* should be OK if null.
*/
protected BasicTestIterator(PrefixResolver nscontext)
{
super(nscontext);
}
/**
* Create a LocPathIterator object, including creation
* of step walkers from the opcode list, and call back
* into the Compiler to create predicate expressions.
*
* @param compiler The Compiler which is creating
* this expression.
* @param opPos The position of this iterator in the
* opcode list from the compiler.
*
* @throws javax.xml.transform.TransformerException
*/
protected BasicTestIterator(Compiler compiler, int opPos, int analysis)
throws javax.xml.transform.TransformerException
{
super(compiler, opPos, analysis, false);
int firstStepPos = OpMap.getFirstChildPos(opPos);
int whatToShow = compiler.getWhatToShow(firstStepPos);
if ((0 == (whatToShow
& (DTMFilter.SHOW_ATTRIBUTE
| DTMFilter.SHOW_NAMESPACE
| DTMFilter.SHOW_ELEMENT
| DTMFilter.SHOW_PROCESSING_INSTRUCTION)))
|| (whatToShow == DTMFilter.SHOW_ALL))
initNodeTest(whatToShow);
else
{
initNodeTest(whatToShow, compiler.getStepNS(firstStepPos),
compiler.getStepLocalName(firstStepPos));
}
initPredicateInfo(compiler, firstStepPos);
}
/**
* Create a LocPathIterator object, including creation
* of step walkers from the opcode list, and call back
* into the Compiler to create predicate expressions.
*
* @param compiler The Compiler which is creating
* this expression.
* @param opPos The position of this iterator in the
* opcode list from the compiler.
* @param shouldLoadWalkers True if walkers should be
* loaded, or false if this is a derived iterator and
* it doesn't wish to load child walkers.
*
* @throws javax.xml.transform.TransformerException
*/
protected BasicTestIterator(
Compiler compiler, int opPos, int analysis, boolean shouldLoadWalkers)
throws javax.xml.transform.TransformerException
{
super(compiler, opPos, analysis, shouldLoadWalkers);
}
/**
* Get the next node via getNextXXX. Bottlenecked for derived class override.
* @return The next node on the axis, or DTM.NULL.
*/
protected abstract int getNextNode();
/**
* Returns the next node in the set and advances the position of the
* iterator in the set. After a NodeIterator is created, the first call
* to nextNode() returns the first node in the set.
*
* @return The next Node
in the set being iterated over, or
* null
if there are no more members in that set.
*/
public int nextNode()
{
if(m_foundLast)
{
m_lastFetched = DTM.NULL;
return DTM.NULL;
}
if(DTM.NULL == m_lastFetched)
{
resetProximityPositions();
}
int next;
org.apache.xpath.VariableStack vars;
int savedStart;
if (-1 != m_stackFrame)
{
vars = m_execContext.getVarStack();
// These three statements need to be combined into one operation.
savedStart = vars.getStackFrame();
vars.setStackFrame(m_stackFrame);
}
else
{
// Yuck. Just to shut up the compiler!
vars = null;
savedStart = 0;
}
try
{
do
{
next = getNextNode();
if (DTM.NULL != next)
{
if(DTMIterator.FILTER_ACCEPT == acceptNode(next))
break;
else
continue;
}
else
break;
}
while (next != DTM.NULL);
if (DTM.NULL != next)
{
m_pos++;
return next;
}
else
{
m_foundLast = true;
return DTM.NULL;
}
}
finally
{
if (-1 != m_stackFrame)
{
// These two statements need to be combined into one operation.
vars.setStackFrame(savedStart);
}
}
}
/**
* Get a cloned Iterator that is reset to the beginning
* of the query.
*
* @return A cloned NodeIterator set of the start of the query.
*
* @throws CloneNotSupportedException
*/
public DTMIterator cloneWithReset() throws CloneNotSupportedException
{
ChildTestIterator clone = (ChildTestIterator) super.cloneWithReset();
clone.resetProximityPositions();
return clone;
}
}