bpel-compiler/src/main/java/org/apache/ode/bpel/elang/xquery10/compiler/XQuery10ExpressionCompilerImpl.java - ode - Git at Google

 /*
  * 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.
  */

 package org.apache.ode.bpel.elang.xquery10.compiler;

 import java.net.URI;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;

 import javax.xml.namespace.QName;
 import javax.xml.transform.Source;
 import javax.xml.transform.TransformerFactory;
 import javax.xml.xquery.XQConnection;
 import javax.xml.xquery.XQConstants;
 import javax.xml.xquery.XQDataSource;
 import javax.xml.xquery.XQException;
 import javax.xml.xquery.XQItemType;
 import javax.xml.xquery.XQPreparedExpression;
 import javax.xml.xquery.XQSequence;
 import javax.xml.xquery.XQStaticContext;

 import net.sf.saxon.Configuration;
 import net.sf.saxon.om.Validation;
 import net.sf.saxon.xqj.SaxonXQConnection;
 import net.sf.saxon.xqj.SaxonXQDataSource;

 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.apache.ode.bpel.compiler.api.CompilationException;
 import org.apache.ode.bpel.compiler.api.CompilerContext;
 import org.apache.ode.bpel.compiler.api.ExpressionCompiler;
 import org.apache.ode.bpel.compiler.bom.Expression;
 import org.apache.ode.bpel.elang.xpath10.compiler.XPathMessages;
 import org.apache.ode.bpel.elang.xpath10.compiler.XslCompilationErrorListener;
 import org.apache.ode.bpel.elang.xpath20.compiler.Constants;
 import org.apache.ode.bpel.elang.xpath20.compiler.JaxpFunctionResolver;
 import org.apache.ode.bpel.elang.xpath20.compiler.JaxpVariableResolver;
 import org.apache.ode.bpel.elang.xpath20.compiler.WrappedResolverException;
 import org.apache.ode.bpel.elang.xquery10.obj.OXQuery10ExpressionBPEL20;
 import org.apache.ode.bpel.obj.OConstantVarType;
 import org.apache.ode.bpel.obj.OElementVarType;
 import org.apache.ode.bpel.obj.OExpression;
 import org.apache.ode.bpel.obj.OLValueExpression;
 import org.apache.ode.bpel.obj.OMessageVarType;
 import org.apache.ode.bpel.obj.OScope;
 import org.apache.ode.bpel.obj.OVarType;
 import org.apache.ode.bpel.obj.OXsdTypeVarType;
 import org.apache.ode.bpel.obj.OMessageVarType.Part;
 import org.apache.ode.utils.DOMUtils;
 import org.apache.ode.utils.NSContext;
 import org.apache.ode.utils.Namespaces;
 import org.apache.ode.utils.msg.MessageBundle;
 import org.apache.ode.utils.xsl.XslTransformHandler;
 import org.apache.xml.utils.XMLChar;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;

 /**
  * XQuery compiler based on the SAXON implementation.
  */
 public class XQuery10ExpressionCompilerImpl implements ExpressionCompiler {

     protected static final Logger __log = LoggerFactory.getLogger(XQuery10ExpressionCompilerImpl.class);

     protected String _bpelNS;
     protected QName _qnLinkStatus;
     protected QName _qnVarProp;
     protected QName _qnVarData;
     protected QName _qnXslTransform;

     protected final XPathMessages __msgs = MessageBundle.getMessages(XPathMessages.class);
     protected Map<String, String> _properties = new HashMap<String, String>();
     protected CompilerContext _compilerContext;

     public XQuery10ExpressionCompilerImpl(String bpelNS) {
         _bpelNS = bpelNS;
         _qnLinkStatus = new QName(_bpelNS, Constants.EXT_FUNCTION_GETLINKSTATUS);
         _qnVarProp = new QName(_bpelNS, Constants.EXT_FUNCTION_GETVARIABLEPROPERTY);
         _qnVarData = new QName(_bpelNS, Constants.EXT_FUNCTION_GETVARIABLEDATA);
         _qnXslTransform = new QName(_bpelNS, Constants.EXT_FUNCTION_DOXSLTRANSFORM);

         _properties.put("runtime-class", "org.apache.ode.bpel.elang.xquery10.runtime.XQuery10ExpressionRuntime");
         TransformerFactory trsf = new net.sf.saxon.TransformerFactoryImpl();
         XslTransformHandler.getInstance().setTransformerFactory(trsf);
     }

     public void setCompilerContext(CompilerContext compilerContext) {
         _compilerContext = compilerContext;
         XslCompilationErrorListener xe = new XslCompilationErrorListener(compilerContext);
         XslTransformHandler.getInstance().setErrorListener(xe);
     }

     /**
      * @see org.apache.ode.bpel.compiler.api.ExpressionCompiler#compileJoinCondition(java.lang.Object)
      */
     public OExpression compileJoinCondition(Object source) throws CompilationException {
         return _compile((Expression) source, true);
     }

     /**
      * @see org.apache.ode.bpel.compiler.api.ExpressionCompiler#compile(java.lang.Object)
      */
     public OExpression compile(Object source) throws CompilationException {
         return _compile((Expression) source, false);
     }

     /**
      * @see org.apache.ode.bpel.compiler.api.ExpressionCompiler#compileLValue(java.lang.Object)
      */
     public OLValueExpression compileLValue(Object source) throws CompilationException {
         return (OLValueExpression) _compile((Expression) source, false);
     }

     /**
      * @see org.apache.ode.bpel.compiler.api.ExpressionCompiler#compile(java.lang.Object)
      */
     private OExpression _compile(org.apache.ode.bpel.compiler.bom.Expression xquery, boolean isJoinCondition)
             throws CompilationException {
         OXQuery10ExpressionBPEL20 oexp = new OXQuery10ExpressionBPEL20(_compilerContext.getOProcess(), _qnVarData,
                 _qnVarProp, _qnLinkStatus, _qnXslTransform, isJoinCondition);
         oexp.setNamespaceCtx(xquery.getNamespaceContext());
         doJaxpCompile(oexp, xquery);
         return oexp;
     }

     private void doJaxpCompile(OXQuery10ExpressionBPEL20 out, Expression source) throws CompilationException {
         String xqueryStr;
         Node node = source.getExpression();
         if (node == null) {
             throw new CompilationException(__msgs.errEmptyExpression(source.getURI(), new QName(source.getElement().getNamespaceURI(), source.getElement().getNodeName())));
         }
         if (node.getNodeType() != Node.TEXT_NODE &&
                 node.getNodeType() != Node.ELEMENT_NODE &&
                 node.getNodeType() != Node.CDATA_SECTION_NODE) {
             throw new CompilationException(__msgs.errUnexpectedNodeTypeForXPath(DOMUtils.domToString(node)));
         }
         xqueryStr = DOMUtils.domToString(node);
         xqueryStr = xqueryStr.trim();
         if (xqueryStr.length() == 0) {
             throw new CompilationException(__msgs.warnXPath20Syntax(DOMUtils.domToString(node), "empty string"));
         }

         try {
             XQDataSource xqds = new SaxonXQDataSource(new Configuration());
             XQConnection xqconn = xqds.getConnection();

             __log.debug("Compiling expression " + xqueryStr);
             Configuration configuration = ((SaxonXQConnection) xqconn).getConfiguration();
             configuration.setAllNodesUntyped(true);
             configuration.setHostLanguage(Configuration.XQUERY);

             XQStaticContext staticContext = xqconn.getStaticContext();
             JaxpFunctionResolver funcResolver = new JaxpFunctionResolver(
                     _compilerContext, out, source.getNamespaceContext(), _bpelNS);
             JaxpVariableResolver variableResolver = new JaxpVariableResolver(
                     _compilerContext, out);

             XQueryDeclarations declarations = new XQueryDeclarations();
             NSContext nsContext = source.getNamespaceContext();
             Set<String> prefixes = nsContext.getPrefixes();
             if (!nsContext.getUriSet().contains(Namespaces.ODE_EXTENSION_NS)) {
                 nsContext.register("ode", Namespaces.ODE_EXTENSION_NS);
             }
             for (String prefix : prefixes) {
                 String uri = nsContext.getNamespaceURI(prefix);
                 staticContext.declareNamespace(prefix, uri);
                 if ("".equals(prefix)) {
                     declarations.declareDefaultElementNamespace(uri);
                 } else if ("bpws".equals(prefix)) {
                     declarations.declareNamespace("bpws", "java:" + Constants.XQUERY_FUNCTION_HANDLER_COMPILER);
                 } else {
                     declarations.declareNamespace(prefix, uri);
                 }
             }
             declarations.declareVariable(
                     getQName(nsContext, Namespaces.ODE_EXTENSION_NS, "pid"),
                     getQName(nsContext, Namespaces.XML_SCHEMA, "integer"));
 //            Map<URI, Source> schemaDocuments = _compilerContext.getSchemaSources();
 //            for (URI schemaUri : schemaDocuments.keySet()) {
 //            	Source schemaSource = schemaDocuments.get(schemaUri);
 //            	// Don't add schema sources, since our Saxon library is not schema-aware.
 //            	// configuration.addSchemaSource(schemaSource);
 //            }
             configuration.setSchemaValidationMode(Validation.SKIP);
             List<OScope.Variable> variables = _compilerContext.getAccessibleVariables();
             Map<QName, QName> variableTypes = new HashMap<QName, QName>();
             for (String variableName : getVariableNames(xqueryStr)) {
                 OScope.Variable variable = getVariable(variables, variableName);
                 if (variable == null) {
                     continue;
                 }
                 OVarType type = variable.getType();
                 QName nameQName = getNameQName(variableName);
                 QName typeQName = getTypeQName(variableName, type);
                 variableTypes.put(nameQName, typeQName);
                 String prefix = typeQName.getPrefix();
                 if (prefix == null || "".equals(prefix.trim())) {
                     prefix = getPrefixForUri(nsContext, typeQName.getNamespaceURI());
                 }
                 // don't declare typed variables, as our engine is not schema-aware
                 // declarations.declareVariable(variable.name, typeQName);
                 declarations.declareVariable(variableName);
             }

             // Add implicit declarations as prolog to the user-defined XQuery
             out.setXquery((declarations.toString()) + xqueryStr);

             // Check the XQuery for compilation errors
             xqconn.setStaticContext(staticContext);
             XQPreparedExpression exp = xqconn.prepareExpression(out.getXquery());

             // Pre-evaluate variables and functions by executing query
             node.setUserData(XQuery10BpelFunctions.USER_DATA_KEY_FUNCTION_RESOLVER,
                     funcResolver, null);
             exp.bindItem(XQConstants.CONTEXT_ITEM,
                     xqconn.createItemFromNode(node, xqconn.createNodeType()));
             // Bind external variables to dummy runtime values
             for (QName variable : exp.getAllUnboundExternalVariables()) {
                 QName typeQName = variableTypes.get(variable);
                 Object value = variableResolver.resolveVariable(variable);
                 if (typeQName != null) {
                     if (value.getClass().getName().startsWith("java.lang")) {
                         exp.bindAtomicValue(variable, value.toString(),
                                 xqconn.createAtomicType(XQItemType.XQBASETYPE_ANYATOMICTYPE));
                     } else if (value instanceof Node) {
                         exp.bindNode(variable, (Node) value, xqconn.createNodeType());
                     } else if (value instanceof NodeList) {
                         NodeList nodeList = (NodeList) value;
                         ArrayList nodeArray = new ArrayList();
                         for (int i = 0; i < nodeList.getLength(); i++) {
                             nodeArray.add(nodeList.item(i));
                         }
                         XQSequence sequence = xqconn.createSequence(nodeArray.iterator());
                         exp.bindSequence(variable, sequence);
                     }
                 }
             }
             // evaluate the expression so as to initialize the variables
             try {
                 exp.executeQuery();
             } catch (XQException xpee) {
                 // swallow errors caused by uninitialized variables
             } finally {
                 // reset the expression's user data, in order to avoid
                 // serializing the function resolver in the compiled bpel file.
                 if (node != null) {
                     node.setUserData(XQuery10BpelFunctions.USER_DATA_KEY_FUNCTION_RESOLVER, null, null);
                 }
             }
         } catch (XQException xqe) {
             __log.debug("",xqe);
             __log.info("Couldn't validate properly expression " + xqueryStr);
             throw new CompilationException(__msgs.errXQuery10Syntax(xqueryStr, "Couldn't validate XQuery expression"));
         } catch (WrappedResolverException wre) {
             if (wre._compilationMsg != null)
                 throw new CompilationException(wre._compilationMsg, wre);
             if (wre.getCause() instanceof CompilationException)
                 throw (CompilationException) wre.getCause();
             throw wre;
         }
     }

     public Map<String, String> getProperties() {
         return _properties;
     }

     private String getQName(NSContext nsContext, String uri, String localPart) {
         String prefix = getPrefixForUri(nsContext, uri);
         return (prefix == null ? localPart : (prefix + ":" + localPart));
     }

     private String getPrefixForUri(NSContext nsContext, String uri) {
         Set<String> prefixes = nsContext.getPrefixes();
         for (String prefix : prefixes) {
             String anUri = (nsContext.getNamespaceURI(prefix));
             if (anUri != null && anUri.equals(uri)) {
                 return prefix;
             }
         }
         return null;
     }

     protected static Collection<String> getVariableNames(String xquery) {
         Collection<String> variableNames = new LinkedHashSet<String>();
         for (int index = xquery.indexOf("$"); index != -1; index = xquery.indexOf("$")) {
             StringBuilder variableName = new StringBuilder();
             index++;
             while(index < xquery.length() && XMLChar.isNCName(xquery.charAt(index))) {
                 variableName.append(xquery.charAt(index++));
             }
             variableNames.add(variableName.toString());
             xquery = xquery.substring(index);
         }
         return variableNames;
     }

     private OScope.Variable getVariable(List<OScope.Variable> variables, String variableName) {
         String declaredVariable = getVariableDeclaredName(variableName);
         for (OScope.Variable variable : variables) {
             if (variable.getName().equals(declaredVariable)) {
                 return variable;
             }
         }
         return null;
     }

     private String getVariableDeclaredName(String variableReference) {
         int dotIndex = variableReference.indexOf(".");
         return dotIndex >= 0 ? variableReference.substring(0, dotIndex) : variableReference;
     }

     private String getVariablePartName(String variableReference) {
         int dotIndex = variableReference.indexOf(".");
         return dotIndex >= 0 ? variableReference.substring(dotIndex + 1) : "";
     }

     private QName getNameQName(String variableName) {
         String prefix = null, localName = null;;
         int colonIndex = variableName.indexOf(":");
         if (colonIndex >= 0) {
             prefix = variableName.substring(0, colonIndex);
             localName = variableName.substring(colonIndex + 1);
         } else {
             prefix = "";
             localName = variableName;
         }
         return new QName(prefix, localName);
     }

     private QName getTypeQName(String variableName, OVarType type) {
         QName typeQName = null;
         if (type instanceof OConstantVarType) {
             typeQName = new QName(Namespaces.XML_SCHEMA, "string", "xs");
         } else if (type instanceof OElementVarType) {
             typeQName = ((OElementVarType) type).getElementType();
         } else if (type instanceof OMessageVarType) {
             Part part = ((OMessageVarType) type).getParts().get(getVariablePartName(variableName));
             if (part != null) {
                 typeQName = getTypeQName(variableName, part.getType());
             }
         } else if (type instanceof OXsdTypeVarType) {
             typeQName = ((OXsdTypeVarType) type).getXsdType();
         }
         return typeQName;
     }

     private static class XQueryDeclarations {
         StringBuffer declarations = new StringBuffer();

         public XQueryDeclarations() {}

         public void declareVariable(String name, QName type) {
             declareVariable(name, type.getPrefix() + ":" + type.getLocalPart());
         }

         public void declareVariable(String name, String type) {
             declarations.append("declare variable ")
                 .append("$")
                 .append(name)
                 .append(" as ")
                 .append(type)
                 .append(" external ")
                 .append(";\n");
         }

         public void declareVariable(String name) {
             declarations.append("declare variable ")
                 .append("$")
                 .append(name)
                 .append(" external ")
                 .append(";\n");
         }

         public void declareNamespace(String prefix, String uri) {
             declarations.append("declare namespace ")
                 .append(prefix)
                 .append("=")
                 .append("\"" + uri + "\"")
                 .append(";\n");
         }

         public void declareDefaultElementNamespace(String uri) {
             declarations.append("declare default element namespace ")
                 .append("\"" + uri + "\"")
                 .append(";\n");
         }

         public String toString() {
             return declarations.toString();
         }
     }
 }
	/*
	* 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.
	*/

	package org.apache.ode.bpel.elang.xquery10.compiler;

	import java.net.URI;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.HashMap;
	import java.util.LinkedHashSet;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;

	import javax.xml.namespace.QName;
	import javax.xml.transform.Source;
	import javax.xml.transform.TransformerFactory;
	import javax.xml.xquery.XQConnection;
	import javax.xml.xquery.XQConstants;
	import javax.xml.xquery.XQDataSource;
	import javax.xml.xquery.XQException;
	import javax.xml.xquery.XQItemType;
	import javax.xml.xquery.XQPreparedExpression;
	import javax.xml.xquery.XQSequence;
	import javax.xml.xquery.XQStaticContext;

	import net.sf.saxon.Configuration;
	import net.sf.saxon.om.Validation;
	import net.sf.saxon.xqj.SaxonXQConnection;
	import net.sf.saxon.xqj.SaxonXQDataSource;

	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;
	import org.apache.ode.bpel.compiler.api.CompilationException;
	import org.apache.ode.bpel.compiler.api.CompilerContext;
	import org.apache.ode.bpel.compiler.api.ExpressionCompiler;
	import org.apache.ode.bpel.compiler.bom.Expression;
	import org.apache.ode.bpel.elang.xpath10.compiler.XPathMessages;
	import org.apache.ode.bpel.elang.xpath10.compiler.XslCompilationErrorListener;
	import org.apache.ode.bpel.elang.xpath20.compiler.Constants;
	import org.apache.ode.bpel.elang.xpath20.compiler.JaxpFunctionResolver;
	import org.apache.ode.bpel.elang.xpath20.compiler.JaxpVariableResolver;
	import org.apache.ode.bpel.elang.xpath20.compiler.WrappedResolverException;
	import org.apache.ode.bpel.elang.xquery10.obj.OXQuery10ExpressionBPEL20;
	import org.apache.ode.bpel.obj.OConstantVarType;
	import org.apache.ode.bpel.obj.OElementVarType;
	import org.apache.ode.bpel.obj.OExpression;
	import org.apache.ode.bpel.obj.OLValueExpression;
	import org.apache.ode.bpel.obj.OMessageVarType;
	import org.apache.ode.bpel.obj.OScope;
	import org.apache.ode.bpel.obj.OVarType;
	import org.apache.ode.bpel.obj.OXsdTypeVarType;
	import org.apache.ode.bpel.obj.OMessageVarType.Part;
	import org.apache.ode.utils.DOMUtils;
	import org.apache.ode.utils.NSContext;
	import org.apache.ode.utils.Namespaces;
	import org.apache.ode.utils.msg.MessageBundle;
	import org.apache.ode.utils.xsl.XslTransformHandler;
	import org.apache.xml.utils.XMLChar;
	import org.w3c.dom.Node;
	import org.w3c.dom.NodeList;

	/**
	* XQuery compiler based on the SAXON implementation.
	*/
	public class XQuery10ExpressionCompilerImpl implements ExpressionCompiler {

	protected static final Logger __log = LoggerFactory.getLogger(XQuery10ExpressionCompilerImpl.class);

	protected String _bpelNS;
	protected QName _qnLinkStatus;
	protected QName _qnVarProp;
	protected QName _qnVarData;
	protected QName _qnXslTransform;

	protected final XPathMessages __msgs = MessageBundle.getMessages(XPathMessages.class);
	protected Map<String, String> _properties = new HashMap<String, String>();
	protected CompilerContext _compilerContext;

	public XQuery10ExpressionCompilerImpl(String bpelNS) {
	_bpelNS = bpelNS;
	_qnLinkStatus = new QName(_bpelNS, Constants.EXT_FUNCTION_GETLINKSTATUS);
	_qnVarProp = new QName(_bpelNS, Constants.EXT_FUNCTION_GETVARIABLEPROPERTY);
	_qnVarData = new QName(_bpelNS, Constants.EXT_FUNCTION_GETVARIABLEDATA);
	_qnXslTransform = new QName(_bpelNS, Constants.EXT_FUNCTION_DOXSLTRANSFORM);

	_properties.put("runtime-class", "org.apache.ode.bpel.elang.xquery10.runtime.XQuery10ExpressionRuntime");
	TransformerFactory trsf = new net.sf.saxon.TransformerFactoryImpl();
	XslTransformHandler.getInstance().setTransformerFactory(trsf);
	}

	public void setCompilerContext(CompilerContext compilerContext) {
	_compilerContext = compilerContext;
	XslCompilationErrorListener xe = new XslCompilationErrorListener(compilerContext);
	XslTransformHandler.getInstance().setErrorListener(xe);
	}

	/**
	* @see org.apache.ode.bpel.compiler.api.ExpressionCompiler#compileJoinCondition(java.lang.Object)
	*/
	public OExpression compileJoinCondition(Object source) throws CompilationException {
	return _compile((Expression) source, true);
	}

	/**
	* @see org.apache.ode.bpel.compiler.api.ExpressionCompiler#compile(java.lang.Object)
	*/
	public OExpression compile(Object source) throws CompilationException {
	return _compile((Expression) source, false);
	}

	/**
	* @see org.apache.ode.bpel.compiler.api.ExpressionCompiler#compileLValue(java.lang.Object)
	*/
	public OLValueExpression compileLValue(Object source) throws CompilationException {
	return (OLValueExpression) _compile((Expression) source, false);
	}

	/**
	* @see org.apache.ode.bpel.compiler.api.ExpressionCompiler#compile(java.lang.Object)
	*/
	private OExpression _compile(org.apache.ode.bpel.compiler.bom.Expression xquery, boolean isJoinCondition)
	throws CompilationException {
	OXQuery10ExpressionBPEL20 oexp = new OXQuery10ExpressionBPEL20(_compilerContext.getOProcess(), _qnVarData,
	_qnVarProp, _qnLinkStatus, _qnXslTransform, isJoinCondition);
	oexp.setNamespaceCtx(xquery.getNamespaceContext());
	doJaxpCompile(oexp, xquery);
	return oexp;
	}

	private void doJaxpCompile(OXQuery10ExpressionBPEL20 out, Expression source) throws CompilationException {
	String xqueryStr;
	Node node = source.getExpression();
	if (node == null) {
	throw new CompilationException(__msgs.errEmptyExpression(source.getURI(), new QName(source.getElement().getNamespaceURI(), source.getElement().getNodeName())));
	}
	if (node.getNodeType() != Node.TEXT_NODE &&
	node.getNodeType() != Node.ELEMENT_NODE &&
	node.getNodeType() != Node.CDATA_SECTION_NODE) {
	throw new CompilationException(__msgs.errUnexpectedNodeTypeForXPath(DOMUtils.domToString(node)));
	}
	xqueryStr = DOMUtils.domToString(node);
	xqueryStr = xqueryStr.trim();
	if (xqueryStr.length() == 0) {
	throw new CompilationException(__msgs.warnXPath20Syntax(DOMUtils.domToString(node), "empty string"));
	}

	try {
	XQDataSource xqds = new SaxonXQDataSource(new Configuration());
	XQConnection xqconn = xqds.getConnection();

	__log.debug("Compiling expression " + xqueryStr);
	Configuration configuration = ((SaxonXQConnection) xqconn).getConfiguration();
	configuration.setAllNodesUntyped(true);
	configuration.setHostLanguage(Configuration.XQUERY);

	XQStaticContext staticContext = xqconn.getStaticContext();
	JaxpFunctionResolver funcResolver = new JaxpFunctionResolver(
	_compilerContext, out, source.getNamespaceContext(), _bpelNS);
	JaxpVariableResolver variableResolver = new JaxpVariableResolver(
	_compilerContext, out);

	XQueryDeclarations declarations = new XQueryDeclarations();
	NSContext nsContext = source.getNamespaceContext();
	Set<String> prefixes = nsContext.getPrefixes();
	if (!nsContext.getUriSet().contains(Namespaces.ODE_EXTENSION_NS)) {
	nsContext.register("ode", Namespaces.ODE_EXTENSION_NS);
	}
	for (String prefix : prefixes) {
	String uri = nsContext.getNamespaceURI(prefix);
	staticContext.declareNamespace(prefix, uri);
	if ("".equals(prefix)) {
	declarations.declareDefaultElementNamespace(uri);
	} else if ("bpws".equals(prefix)) {
	declarations.declareNamespace("bpws", "java:" + Constants.XQUERY_FUNCTION_HANDLER_COMPILER);
	} else {
	declarations.declareNamespace(prefix, uri);
	}
	}
	declarations.declareVariable(
	getQName(nsContext, Namespaces.ODE_EXTENSION_NS, "pid"),
	getQName(nsContext, Namespaces.XML_SCHEMA, "integer"));
	// Map<URI, Source> schemaDocuments = _compilerContext.getSchemaSources();
	// for (URI schemaUri : schemaDocuments.keySet()) {
	// Source schemaSource = schemaDocuments.get(schemaUri);
	// // Don't add schema sources, since our Saxon library is not schema-aware.
	// // configuration.addSchemaSource(schemaSource);
	// }
	configuration.setSchemaValidationMode(Validation.SKIP);
	List<OScope.Variable> variables = _compilerContext.getAccessibleVariables();
	Map<QName, QName> variableTypes = new HashMap<QName, QName>();
	for (String variableName : getVariableNames(xqueryStr)) {
	OScope.Variable variable = getVariable(variables, variableName);
	if (variable == null) {
	continue;
	}
	OVarType type = variable.getType();
	QName nameQName = getNameQName(variableName);
	QName typeQName = getTypeQName(variableName, type);
	variableTypes.put(nameQName, typeQName);
	String prefix = typeQName.getPrefix();
	if (prefix == null \|\| "".equals(prefix.trim())) {
	prefix = getPrefixForUri(nsContext, typeQName.getNamespaceURI());
	}
	// don't declare typed variables, as our engine is not schema-aware
	// declarations.declareVariable(variable.name, typeQName);
	declarations.declareVariable(variableName);
	}

	// Add implicit declarations as prolog to the user-defined XQuery
	out.setXquery((declarations.toString()) + xqueryStr);

	// Check the XQuery for compilation errors
	xqconn.setStaticContext(staticContext);
	XQPreparedExpression exp = xqconn.prepareExpression(out.getXquery());

	// Pre-evaluate variables and functions by executing query
	node.setUserData(XQuery10BpelFunctions.USER_DATA_KEY_FUNCTION_RESOLVER,
	funcResolver, null);
	exp.bindItem(XQConstants.CONTEXT_ITEM,
	xqconn.createItemFromNode(node, xqconn.createNodeType()));
	// Bind external variables to dummy runtime values
	for (QName variable : exp.getAllUnboundExternalVariables()) {
	QName typeQName = variableTypes.get(variable);
	Object value = variableResolver.resolveVariable(variable);
	if (typeQName != null) {
	if (value.getClass().getName().startsWith("java.lang")) {
	exp.bindAtomicValue(variable, value.toString(),
	xqconn.createAtomicType(XQItemType.XQBASETYPE_ANYATOMICTYPE));
	} else if (value instanceof Node) {
	exp.bindNode(variable, (Node) value, xqconn.createNodeType());
	} else if (value instanceof NodeList) {
	NodeList nodeList = (NodeList) value;
	ArrayList nodeArray = new ArrayList();
	for (int i = 0; i < nodeList.getLength(); i++) {
	nodeArray.add(nodeList.item(i));
	}
	XQSequence sequence = xqconn.createSequence(nodeArray.iterator());
	exp.bindSequence(variable, sequence);
	}
	}
	}
	// evaluate the expression so as to initialize the variables
	try {
	exp.executeQuery();
	} catch (XQException xpee) {
	// swallow errors caused by uninitialized variables
	} finally {
	// reset the expression's user data, in order to avoid
	// serializing the function resolver in the compiled bpel file.
	if (node != null) {
	node.setUserData(XQuery10BpelFunctions.USER_DATA_KEY_FUNCTION_RESOLVER, null, null);
	}
	}
	} catch (XQException xqe) {
	__log.debug("",xqe);
	__log.info("Couldn't validate properly expression " + xqueryStr);
	throw new CompilationException(__msgs.errXQuery10Syntax(xqueryStr, "Couldn't validate XQuery expression"));
	} catch (WrappedResolverException wre) {
	if (wre._compilationMsg != null)
	throw new CompilationException(wre._compilationMsg, wre);
	if (wre.getCause() instanceof CompilationException)
	throw (CompilationException) wre.getCause();
	throw wre;
	}
	}

	public Map<String, String> getProperties() {
	return _properties;
	}

	private String getQName(NSContext nsContext, String uri, String localPart) {
	String prefix = getPrefixForUri(nsContext, uri);
	return (prefix == null ? localPart : (prefix + ":" + localPart));
	}

	private String getPrefixForUri(NSContext nsContext, String uri) {
	Set<String> prefixes = nsContext.getPrefixes();
	for (String prefix : prefixes) {
	String anUri = (nsContext.getNamespaceURI(prefix));
	if (anUri != null && anUri.equals(uri)) {
	return prefix;
	}
	}
	return null;
	}

	protected static Collection<String> getVariableNames(String xquery) {
	Collection<String> variableNames = new LinkedHashSet<String>();
	for (int index = xquery.indexOf("$"); index != -1; index = xquery.indexOf("$")) {
	StringBuilder variableName = new StringBuilder();
	index++;
	while(index < xquery.length() && XMLChar.isNCName(xquery.charAt(index))) {
	variableName.append(xquery.charAt(index++));
	}
	variableNames.add(variableName.toString());
	xquery = xquery.substring(index);
	}
	return variableNames;
	}

	private OScope.Variable getVariable(List<OScope.Variable> variables, String variableName) {
	String declaredVariable = getVariableDeclaredName(variableName);
	for (OScope.Variable variable : variables) {
	if (variable.getName().equals(declaredVariable)) {
	return variable;
	}
	}
	return null;
	}

	private String getVariableDeclaredName(String variableReference) {
	int dotIndex = variableReference.indexOf(".");
	return dotIndex >= 0 ? variableReference.substring(0, dotIndex) : variableReference;
	}

	private String getVariablePartName(String variableReference) {
	int dotIndex = variableReference.indexOf(".");
	return dotIndex >= 0 ? variableReference.substring(dotIndex + 1) : "";
	}

	private QName getNameQName(String variableName) {
	String prefix = null, localName = null;;
	int colonIndex = variableName.indexOf(":");
	if (colonIndex >= 0) {
	prefix = variableName.substring(0, colonIndex);
	localName = variableName.substring(colonIndex + 1);
	} else {
	prefix = "";
	localName = variableName;
	}
	return new QName(prefix, localName);
	}

	private QName getTypeQName(String variableName, OVarType type) {
	QName typeQName = null;
	if (type instanceof OConstantVarType) {
	typeQName = new QName(Namespaces.XML_SCHEMA, "string", "xs");
	} else if (type instanceof OElementVarType) {
	typeQName = ((OElementVarType) type).getElementType();
	} else if (type instanceof OMessageVarType) {
	Part part = ((OMessageVarType) type).getParts().get(getVariablePartName(variableName));
	if (part != null) {
	typeQName = getTypeQName(variableName, part.getType());
	}
	} else if (type instanceof OXsdTypeVarType) {
	typeQName = ((OXsdTypeVarType) type).getXsdType();
	}
	return typeQName;
	}

	private static class XQueryDeclarations {
	StringBuffer declarations = new StringBuffer();

	public XQueryDeclarations() {}

	public void declareVariable(String name, QName type) {
	declareVariable(name, type.getPrefix() + ":" + type.getLocalPart());
	}

	public void declareVariable(String name, String type) {
	declarations.append("declare variable ")
	.append("$")
	.append(name)
	.append(" as ")
	.append(type)
	.append(" external ")
	.append(";\n");
	}

	public void declareVariable(String name) {
	declarations.append("declare variable ")
	.append("$")
	.append(name)
	.append(" external ")
	.append(";\n");
	}

	public void declareNamespace(String prefix, String uri) {
	declarations.append("declare namespace ")
	.append(prefix)
	.append("=")
	.append("\"" + uri + "\"")
	.append(";\n");
	}

	public void declareDefaultElementNamespace(String uri) {
	declarations.append("declare default element namespace ")
	.append("\"" + uri + "\"")
	.append(";\n");
	}

	public String toString() {
	return declarations.toString();
	}
	}
	}