org.apache.xpath.objects.XRTreeFrag 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: XRTreeFrag.java 469368 2006-10-31 04:41:36Z minchau $
*/
package org.apache.xpath.objects;
import org.apache.xml.dtm.DTM;
import org.apache.xml.dtm.DTMIterator;
import org.apache.xml.utils.XMLString;
import org.apache.xpath.Expression;
import org.apache.xpath.ExpressionNode;
import org.apache.xpath.XPathContext;
import org.apache.xpath.axes.RTFIterator;
import org.w3c.dom.NodeList;
/**
* This class represents an XPath result tree fragment object, and is capable of
* converting the RTF to other types, such as a string.
* @xsl.usage general
*/
public class XRTreeFrag extends XObject implements Cloneable
{
static final long serialVersionUID = -3201553822254911567L;
private DTMXRTreeFrag m_DTMXRTreeFrag;
private int m_dtmRoot = DTM.NULL;
protected boolean m_allowRelease = false;
/**
* Create an XRTreeFrag Object.
*
*/
public XRTreeFrag(int root, XPathContext xctxt, ExpressionNode parent)
{
super(null);
exprSetParent(parent);
initDTM(root, xctxt);
}
/**
* Create an XRTreeFrag Object.
*
*/
public XRTreeFrag(int root, XPathContext xctxt)
{
super(null);
initDTM(root, xctxt);
}
private final void initDTM(int root, XPathContext xctxt){
m_dtmRoot = root;
final DTM dtm = xctxt.getDTM(root);
if(dtm != null){
m_DTMXRTreeFrag = xctxt.getDTMXRTreeFrag(xctxt.getDTMIdentity(dtm));
}
}
/**
* Return a java object that's closest to the representation
* that should be handed to an extension.
*
* @return The object that this class wraps
*/
public Object object()
{
if (m_DTMXRTreeFrag.getXPathContext() != null)
return new org.apache.xml.dtm.ref.DTMNodeIterator((DTMIterator)(new org.apache.xpath.NodeSetDTM(m_dtmRoot, m_DTMXRTreeFrag.getXPathContext().getDTMManager())));
else
return super.object();
}
/**
* Create an XRTreeFrag Object.
*
*/
public XRTreeFrag(Expression expr)
{
super(expr);
}
/**
* Specify if it's OK for detach to release the iterator for reuse.
*
* @param allowRelease true if it is OK for detach to release this iterator
* for pooling.
*/
public void allowDetachToRelease(boolean allowRelease)
{
m_allowRelease = allowRelease;
}
/**
* Detaches the DTMIterator from the set which it iterated
* over, releasing any computational resources and placing the iterator
* in the INVALID state. After detach has been invoked,
* calls to nextNode or previousNode will
* raise a runtime exception.
*
* In general, detach should only be called once on the object.
*/
public void detach(){
if(m_allowRelease){
m_DTMXRTreeFrag.destruct();
setObject(null);
}
}
/**
* Tell what kind of class this is.
*
* @return type CLASS_RTREEFRAG
*/
public int getType()
{
return CLASS_RTREEFRAG;
}
/**
* Given a request type, return the equivalent string.
* For diagnostic purposes.
*
* @return type string "#RTREEFRAG"
*/
public String getTypeString()
{
return "#RTREEFRAG";
}
/**
* Cast result object to a number.
*
* @return The result tree fragment as a number or NaN
*/
public double num()
throws javax.xml.transform.TransformerException
{
XMLString s = xstr();
return s.toDouble();
}
/**
* Cast result object to a boolean. This always returns true for a RTreeFrag
* because it is treated like a node-set with a single root node.
*
* @return true
*/
public boolean bool()
{
return true;
}
private XMLString m_xmlStr = null;
/**
* Cast result object to an XMLString.
*
* @return The document fragment node data or the empty string.
*/
public XMLString xstr()
{
if(null == m_xmlStr)
m_xmlStr = m_DTMXRTreeFrag.getDTM().getStringValue(m_dtmRoot);
return m_xmlStr;
}
/**
* Cast result object to a string.
*
* @return The string this wraps or the empty string if null
*/
public void appendToFsb(org.apache.xml.utils.FastStringBuffer fsb)
{
XString xstring = (XString)xstr();
xstring.appendToFsb(fsb);
}
/**
* Cast result object to a string.
*
* @return The document fragment node data or the empty string.
*/
public String str()
{
String str = m_DTMXRTreeFrag.getDTM().getStringValue(m_dtmRoot).toString();
return (null == str) ? "" : str;
}
/**
* Cast result object to a result tree fragment.
*
* @return The document fragment this wraps
*/
public int rtf()
{
return m_dtmRoot;
}
/**
* Cast result object to a DTMIterator.
* dml - modified to return an RTFIterator for
* benefit of EXSLT object-type function in
* {@link org.apache.xalan.lib.ExsltCommon}.
* @return The document fragment as a DTMIterator
*/
public DTMIterator asNodeIterator()
{
return new RTFIterator(m_dtmRoot, m_DTMXRTreeFrag.getXPathContext().getDTMManager());
}
/**
* Cast result object to a nodelist. (special function).
*
* @return The document fragment as a nodelist
*/
public NodeList convertToNodeset()
{
if (m_obj instanceof NodeList)
return (NodeList) m_obj;
else
return new org.apache.xml.dtm.ref.DTMNodeList(asNodeIterator());
}
/**
* Tell if two objects are functionally equal.
*
* @param obj2 Object to compare this to
*
* @return True if the two objects are equal
*
* @throws javax.xml.transform.TransformerException
*/
public boolean equals(XObject obj2)
{
try
{
if (XObject.CLASS_NODESET == obj2.getType())
{
// In order to handle the 'all' semantics of
// nodeset comparisons, we always call the
// nodeset function.
return obj2.equals(this);
}
else if (XObject.CLASS_BOOLEAN == obj2.getType())
{
return bool() == obj2.bool();
}
else if (XObject.CLASS_NUMBER == obj2.getType())
{
return num() == obj2.num();
}
else if (XObject.CLASS_NODESET == obj2.getType())
{
return xstr().equals(obj2.xstr());
}
else if (XObject.CLASS_STRING == obj2.getType())
{
return xstr().equals(obj2.xstr());
}
else if (XObject.CLASS_RTREEFRAG == obj2.getType())
{
// Probably not so good. Think about this.
return xstr().equals(obj2.xstr());
}
else
{
return super.equals(obj2);
}
}
catch(javax.xml.transform.TransformerException te)
{
throw new org.apache.xml.utils.WrappedRuntimeException(te);
}
}
}