Attachment #35598 for bug #61875

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import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.tagext.TagSupport;
import javax.xml.transform.TransformerException;

import org.apache.taglibs.standard.util.EscapeXML;
import org.apache.taglibs.standard.xpath.JSTLXPathCompiler;
import org.apache.taglibs.standard.xpath.JSTLXPathExpression;
import org.apache.taglibs.standard.xpath.JSTLXPathFactory;

/**
 * Tag handler for &lt;out&gt; in JSTL's XML library. TODO: should we rename
 * this to OutSupport to match the tag name?
 *
 * @author Shawn Bayern
 */
public abstract class ExprSupport extends TagSupport {

	private JSTLXPathCompiler compiler;
	private JSTLXPathExpression select;
	protected boolean escapeXml = true; // tag attribute

	public ExprSupport() {
		JSTLXPathFactory xpf = JSTLXPathFactory.getFactory();
		compiler = xpf.newCompiler();
	}
    }

	@Override
	public void release() {
		super.release();
		compiler = null;
		select = null;
	}

	// *********************************************************************
	// Tag logic
    public int doStartTag() throws JspException {
        try {
            XPathContext context = XalanUtil.getContext(this, pageContext);
            String result = select.execute(context, context.getCurrentNode(), null).str();
            EscapeXML.emit(result, escapeXml, pageContext.getOut());
            return SKIP_BODY;
        } catch (IOException ex) {
            throw new JspTagException(ex.toString(), ex);
        } catch (TransformerException e) {
            throw new JspTagException(e);
        }
    }

	// applies XPath expression from 'select' and prints the result
	@Override
	public int doStartTag() throws JspException {
		try {
			String result = select.evaluateString(ForEachTag.getContext(this), pageContext);
			EscapeXML.emit(result, escapeXml, pageContext.getOut());
			return SKIP_BODY;
		} catch (IOException ex) {
			throw new JspTagException(ex.toString(), ex);
		}
	}

	public void setSelect(String select) {
		this.select = compiler.compile(select);
	}
}





package org.apache.taglibs.standard.tag.common.xml;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.jstl.core.LoopTagSupport;
import javax.servlet.jsp.tagext.Tag;
import javax.servlet.jsp.tagext.TagSupport;

import org.apache.taglibs.standard.xpath.JSTLXPathCompiler;
import org.apache.taglibs.standard.xpath.JSTLXPathContext;
import org.apache.taglibs.standard.xpath.JSTLXPathExpression;
import org.apache.taglibs.standard.xpath.JSTLXPathFactory;

/**
 * Implementation of &lt;x:forEach&gt; tag using low-level Xalan API.

 */
public class ForEachTag extends LoopTagSupport {

	private JSTLXPathCompiler compiler;
	private JSTLXPathExpression select;
	private JSTLXPathContext context;

	public ForEachTag() {
		JSTLXPathFactory xpf = JSTLXPathFactory.getFactory();
		compiler = xpf.newCompiler();
	}
        context = null;
    }

	@Override
	public void release() {
		super.release();
		compiler = null;
		select = null;
		context = null;
	}

	@Override
	protected void prepare() throws JspTagException {
		context = select.iterate(getContext(this), pageContext);
	}
            throw new JspTagException(e);
        }
    }

	@Override
	protected boolean hasNext() throws JspTagException {
		return context.hasNext();
	}
    }

	@Override
	protected Object next() throws JspTagException {
		return context.next();
	}
        context.pushCurrentNode(next);
        return iterator.getDTM(next).getNode(next);
    }

	public void setSelect(String select) {
		this.select = compiler.compile(select);
	}
        context.popCurrentNode();
        return super.doAfterBody();
    }

	public void setBegin(int begin) throws JspTagException {
		this.beginSpecified = true;
		this.begin = begin;
		validateBegin();
	}
            context.popContextNodeList();
            context = null;
        }
        super.doFinally();
    }

	public void setEnd(int end) throws JspTagException {
		this.endSpecified = true;
		this.end = end;
		validateEnd();
	}
        }
    }

	public void setStep(int step) throws JspTagException {
		this.stepSpecified = true;
		this.step = step;
		validateStep();
	}

	/* Retrieves the current context. */
	public static JSTLXPathContext getContext(Tag child) {
		ForEachTag forEachTag = (ForEachTag) TagSupport.findAncestorWithClass(child, ForEachTag.class);
		if (forEachTag == null) {
			return null;
		} else {
			return forEachTag.context;
		}
	}
        validateStep();
    }

    /**
     * Return the current XPath context to support expression evaluation in nested tags.
     *
     * @return the current XPath context
     */
    XPathContext getContext() {
        return context;
    }
}


Lines 19-61 Link Here

(-)impl/src/main/java/org/apache/taglibs/standard/tag/common/xml/IfTag.java (-26 / +25 lines)
19		19
20	import javax.servlet.jsp.JspTagException;	20	import javax.servlet.jsp.JspTagException;
21	import javax.servlet.jsp.jstl.core.ConditionalTagSupport;	21	import javax.servlet.jsp.jstl.core.ConditionalTagSupport;
22	import javax.xml.transform.TransformerException;
23		22
24	import org.apache.xpath.XPath;	23	import org.apache.taglibs.standard.xpath.JSTLXPathCompiler;
25	import org.apache.xpath.XPathContext;	24	import org.apache.taglibs.standard.xpath.JSTLXPathExpression;
		25	import org.apache.taglibs.standard.xpath.JSTLXPathFactory;
26		26
27	/**	27	/**
28	* <p>Tag handler for <if> in JSTL's XML library.</p>	28	* <p>
		29	* Tag handler for <if> in JSTL's XML library.
		30	* </p>
29	*	31	*
30	* @author Shawn Bayern	32	* @author Shawn Bayern
31	*/	33	*/
32		34
33	public class IfTag extends ConditionalTagSupport {	35	public class IfTag extends ConditionalTagSupport {
34		36
35	private XPath select;	37	private JSTLXPathCompiler compiler;
		38	private JSTLXPathExpression select;
36		39
		40	public IfTag() {
		41	JSTLXPathFactory xpf = JSTLXPathFactory.getFactory();
		42	compiler = xpf.newCompiler();
		43	}
37		44
38	@Override	45	@Override
39	public void release() {	46	public void release() {
40	super.release();	47	super.release();
41	select = null;	48	compiler = null;
42	}	49	select = null;
		50	}
43		51
44	@Override	52	@Override
45	protected boolean condition() throws JspTagException {	53	protected boolean condition() throws JspTagException {
46	XPathContext context = XalanUtil.getContext(this, pageContext);	54	return select.evaluateBoolean(ForEachTag.getContext(this), pageContext);
47	try {	55	}
48	return select.bool(context, context.getCurrentNode(), null);
49	} catch (TransformerException e) {
50	throw new JspTagException(e);
51	}
52	}
53		56
54	public void setSelect(String select) {	57	public void setSelect(String select) {
55	try {	58	this.select = compiler.compile(select);
56	this.select = new XPath(select, null, null, XPath.SELECT);	59	}
57	} catch (TransformerException e) {
58	throw new AssertionError();
59	}
60	}
61	}	60	}




package org.apache.taglibs.standard.tag.common.xml;

import javax.servlet.jsp.JspException;
//import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.TagSupport;
//import javax.xml.transform.TransformerException;

import org.apache.taglibs.standard.tag.common.core.Util;
import org.apache.taglibs.standard.xpath.JSTLXPathCompiler;
import org.apache.taglibs.standard.xpath.JSTLXPathExpression;
import org.apache.taglibs.standard.xpath.JSTLXPathFactory;
//import org.apache.xpath.XPath;
//import org.apache.xpath.XPathContext;
//import org.apache.xpath.objects.XObject;

/**
 * <p>
 * Tag handler for &lt;set&gt; in JSTL's XML library.
 * </p>
 *
 * @author Shawn Bayern
 */
public class SetTag extends TagSupport {

	private JSTLXPathCompiler compiler;
	private JSTLXPathExpression select;
	private String var;
	private int scope = PageContext.PAGE_SCOPE;

	// *********************************************************************
	// Construction and initialization

	public SetTag() {
		JSTLXPathFactory xpf = JSTLXPathFactory.getFactory();
		compiler = xpf.newCompiler();
	}
        var = null;
    }

	@Override
	public void release() {
		super.release();
		compiler = null;
		select = null;
		var = null;
	}

	// *********************************************************************
	// Tag logic

	// applies XPath expression from 'select' and stores the result in 'var'
    public int doStartTag() throws JspException {
        try {
            XPathContext context = XalanUtil.getContext(this, pageContext);
            XObject result = select.execute(context, context.getCurrentNode(), null);
            pageContext.setAttribute(var, XalanUtil.coerceToJava(result), scope);
            return SKIP_BODY;
        } catch (TransformerException e) {
            throw new JspTagException(e);
        }
    }

	@Override
	public int doStartTag() throws JspException {
		Object result = select.evaluateObject(ForEachTag.getContext(this), pageContext);
		pageContext.setAttribute(var, result, scope);
		return SKIP_BODY;
	}

	// *********************************************************************
	// Attribute accessors
            this.select = new XPath(select, null, null, XPath.SELECT);
        } catch (TransformerException e) {
            throw new AssertionError();
        }
    }

	public void setSelect(String select) {
		this.select = compiler.compile(select);
	}

	public void setVar(String var) {
		this.var = var;
	}

	public void setScope(String scope) {
		this.scope = Util.getScope(scope);
	}
}




package org.apache.taglibs.standard.tag.common.xml;

import javax.servlet.jsp.JspTagException;
import javax.xml.transform.TransformerException;

import org.apache.taglibs.standard.tag.common.core.WhenTagSupport;
import org.apache.taglibs.standard.xpath.JSTLXPathCompiler;
import org.apache.taglibs.standard.xpath.JSTLXPathExpression;
import org.apache.taglibs.standard.xpath.JSTLXPathFactory;

/**
 * <p>
 * Tag handler for &lt;if&gt; in JSTL's XML library.
 * </p>
 *
 * @author Shawn Bayern
 */

public class WhenTag extends WhenTagSupport {

	private JSTLXPathCompiler compiler;
	private JSTLXPathExpression select;

	public WhenTag() {
		JSTLXPathFactory xpf = JSTLXPathFactory.getFactory();
		compiler = xpf.newCompiler();
	}
    }

	@Override
	public void release() {
		super.release();
		compiler = null;
		select = null;
	}
            throw new JspTagException(e);
        }
    }

	@Override
	protected boolean condition() throws JspTagException {
		return select.evaluateBoolean(ForEachTag.getContext(this), pageContext);
	}

	public void setSelect(String select) {
		this.select = compiler.compile(select);
	}
}




/*
 * 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.taglibs.standard.tag.common.xml;

import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.Tag;
import javax.servlet.jsp.tagext.TagSupport;
import javax.xml.transform.TransformerException;

import org.apache.taglibs.standard.util.XmlUtil;
import org.apache.xpath.VariableStack;
import org.apache.xpath.XPathContext;
import org.apache.xpath.objects.XBoolean;
import org.apache.xpath.objects.XNodeSet;
import org.apache.xpath.objects.XNumber;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.objects.XString;
import org.w3c.dom.NodeList;

/**
 */
public class XalanUtil {
    /**
     * Return the XPathContext to be used for evaluating expressions.
     *
     * If the child is nested withing a forEach tag its iteration context is used.
     * Otherwise, a new context is created based on an empty Document.
     *
     * @param child the tag whose context should be returned
     * @param pageContext the current page context
     * @return the XPath evaluation context
     */
    public static XPathContext getContext(Tag child, PageContext pageContext) {
        // if within a forEach tag, use its context
        ForEachTag forEachTag = (ForEachTag) TagSupport.findAncestorWithClass(child, ForEachTag.class);
        if (forEachTag != null) {
            return forEachTag.getContext();
        }

        // otherwise, create a new context referring to an empty document
        XPathContext context = new XPathContext(false);
        VariableStack variableStack = new JSTLVariableStack(pageContext);
        context.setVarStack(variableStack);
        int dtm = context.getDTMHandleFromNode(XmlUtil.newEmptyDocument());
        context.pushCurrentNodeAndExpression(dtm, dtm);
        return context;
    }

    /**
     * Return the Java value corresponding to an XPath result.
     *
     * @param xo the XPath type
     * @return the corresponding Java value per the JSTL mapping rules
     * @throws TransformerException if there was a problem converting the type
     */
    static Object coerceToJava(XObject xo) throws TransformerException {
        if (xo instanceof XBoolean) {
            return xo.bool();
        } else if (xo instanceof XNumber) {
            return xo.num();
        } else if (xo instanceof XString) {
            return xo.str();
        } else if (xo instanceof XNodeSet) {
            NodeList nodes = xo.nodelist();
            // if there is only one node in the nodeset return it rather than the list
            if (nodes.getLength() == 1) {
                return nodes.item(0);
            } else {
                return nodes;
            }
        } else {
            // unexpected result type
            throw new AssertionError();
        }
    }
}




/*
	 * 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.taglibs.standard.xpath;

/**
 */
public class InvalidXPathException extends RuntimeException {
	public InvalidXPathException() {
	}

	public InvalidXPathException(String s) {
		super(s);
	}

	public InvalidXPathException(String s, Throwable throwable) {
		super(s, throwable);
	}

	public InvalidXPathException(Throwable throwable) {
		super(throwable);
	}
}
native




/*
	 * 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.taglibs.standard.xpath;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.PageContext;
import javax.xml.XMLConstants;
import javax.xml.namespace.NamespaceContext;
import javax.xml.namespace.QName;
import javax.xml.xpath.XPathVariableResolver;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

/**
 */
public class JSTLVariableResolver implements XPathVariableResolver, NamespaceContext {

	private static enum Scope {
		JSP, PARAM, HEADER, COOKIE, INITPARAM, PAGE, REQUEST, SESSION, APPLICATION
	}

	// Namespace URIs for JSTL implicit variables
	private static final String PARAM_NS_URL = "http://java.sun.com/jstl/xpath/param";
	private static final String HEADER_NS_URL = "http://java.sun.com/jstl/xpath/header";
	private static final String COOKIE_NS_URL = "http://java.sun.com/jstl/xpath/cookie";
	private static final String INITPARAM_NS_URL = "http://java.sun.com/jstl/xpath/initParam";
	private static final String PAGE_NS_URL = "http://java.sun.com/jstl/xpath/page";
	private static final String REQUEST_NS_URL = "http://java.sun.com/jstl/xpath/request";
	private static final String SESSION_NS_URL = "http://java.sun.com/jstl/xpath/session";
	private static final String APP_NS_URL = "http://java.sun.com/jstl/xpath/app";

	// Prefixes for JSTL implicit variables
	private static final String PARAM_PREFIX = "param";
	private static final String HEADER_PREFIX = "header";
	private static final String COOKIE_PREFIX = "cookie";
	private static final String INITPARAM_PREFIX = "initParam";
	private static final String PAGE_PREFIX = "pageScope";
	private static final String REQUEST_PREFIX = "requestScope";
	private static final String SESSION_PREFIX = "sessionScope";
	private static final String APP_PREFIX = "applicationScope";

	// map prefixes to namespaces
	private static final Map<String, String> NAMESPACES;

	static {
		NAMESPACES = new HashMap<String, String>(8);
		NAMESPACES.put(XMLConstants.DEFAULT_NS_PREFIX, XMLConstants.NULL_NS_URI);
		NAMESPACES.put(XMLConstants.XML_NS_PREFIX, XMLConstants.XML_NS_URI);
		NAMESPACES.put(XMLConstants.XMLNS_ATTRIBUTE, XMLConstants.XMLNS_ATTRIBUTE_NS_URI);
		NAMESPACES.put(PARAM_PREFIX, PARAM_NS_URL);
		NAMESPACES.put(HEADER_PREFIX, HEADER_NS_URL);
		NAMESPACES.put(COOKIE_PREFIX, COOKIE_NS_URL);
		NAMESPACES.put(INITPARAM_PREFIX, INITPARAM_NS_URL);
		NAMESPACES.put(PAGE_PREFIX, PAGE_NS_URL);
		NAMESPACES.put(REQUEST_PREFIX, REQUEST_NS_URL);
		NAMESPACES.put(SESSION_PREFIX, SESSION_NS_URL);
		NAMESPACES.put(APP_PREFIX, APP_NS_URL);
	}

	// map namespaces to scopes
	private static final Map<String, Scope> SCOPES;

	static {
		SCOPES = new HashMap<String, Scope>(8);
		SCOPES.put(XMLConstants.NULL_NS_URI, Scope.JSP);
		SCOPES.put(PARAM_NS_URL, Scope.PARAM);
		SCOPES.put(HEADER_NS_URL, Scope.HEADER);
		SCOPES.put(COOKIE_NS_URL, Scope.COOKIE);
		SCOPES.put(INITPARAM_NS_URL, Scope.INITPARAM);
		SCOPES.put(PAGE_NS_URL, Scope.PAGE);
		SCOPES.put(REQUEST_NS_URL, Scope.REQUEST);
		SCOPES.put(SESSION_NS_URL, Scope.SESSION);
		SCOPES.put(APP_NS_URL, Scope.APPLICATION);
	}

	private PageContext pageContext;

	public void setPageContext(PageContext pageContext) {
		this.pageContext = pageContext;
	}

	public Object resolveVariable(QName variableName) {
		String name = variableName.getLocalPart();
		Scope scope = SCOPES.get(variableName.getNamespaceURI());
		if (scope == null) {
			return null;
		}
		switch (scope) {
		case JSP:
			return pageContext.findAttribute(name);
		case PARAM:
			return pageContext.getRequest().getParameter(name);
		case HEADER:
			return ((HttpServletRequest) pageContext.getRequest()).getHeader(name);
		case COOKIE:
			Cookie[] cookies = ((HttpServletRequest) pageContext.getRequest()).getCookies();
			if (cookies != null) {
				for (Cookie cookie : cookies) {
					if (cookie.getName().equals(name)) {
						return cookie.getValue();
					}
				}
			}
			return null;
		case INITPARAM:
			return pageContext.getServletContext().getInitParameter(name);
		case PAGE:
			return pageContext.getAttribute(name, PageContext.PAGE_SCOPE);
		case REQUEST:
			return pageContext.getAttribute(name, PageContext.REQUEST_SCOPE);
		case SESSION:
			return pageContext.getAttribute(name, PageContext.SESSION_SCOPE);
		case APPLICATION:
			return pageContext.getAttribute(name, PageContext.APPLICATION_SCOPE);
		default:
			throw new AssertionError();
		}
	}

	public String getNamespaceURI(String prefix) {
		if (prefix == null) {
			throw new IllegalArgumentException("prefix is null");
		}
		String uri = NAMESPACES.get(prefix);
		if (uri != null) {
			return uri;
		}
		return XMLConstants.NULL_NS_URI;
	}

	public String getPrefix(String namespaceURI) {
		throw new UnsupportedOperationException();
	}

	public Iterator getPrefixes(String namespaceURI) {
		throw new UnsupportedOperationException();
	}
}
native




/*
	 * 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.taglibs.standard.xpath;

/**
 */
public interface JSTLXPathCompiler {

	/**
	 * Pre-compiles an XPath expression for future evaluation;
	 *
	 * @param xpath
	 *            the xpath to compile
	 * @return an JSTLXPathExpression that can be used to evaluate the XPath
	 * @throws InvalidXPathException
	 *             if the supplied XPath is not valid
	 */
	JSTLXPathExpression compile(String xpath) throws InvalidXPathException;
}
native




/*
	 * 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.taglibs.standard.xpath;

/**
 */
public interface JSTLXPathContext {
	boolean hasNext();

	Object next();
}
native




/*
 * 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.taglibs.standard.xpath;

import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.PageContext;

/**
 */
public interface JSTLXPathExpression {

	boolean evaluateBoolean(JSTLXPathContext context, PageContext pageContext) throws JspTagException;

	String evaluateString(JSTLXPathContext context, PageContext pageContext) throws JspTagException;

	Object evaluateObject(JSTLXPathContext context, PageContext pageContext) throws JspTagException;

	JSTLXPathContext iterate(JSTLXPathContext context, PageContext pageContext) throws JspTagException;
}
native




/*
	 * 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.taglibs.standard.xpath;

import org.apache.taglibs.standard.xpath.jaxp.JAXPXPathFactory;

/**
 */
public abstract class JSTLXPathFactory {

	private static final JAXPXPathFactory factory = new JAXPXPathFactory();

	public static JSTLXPathFactory getFactory() {
		return factory;
	}

	public abstract JSTLXPathCompiler newCompiler();
}
native




/*
	 * 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.taglibs.standard.xpath.jaxp;

import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathExpressionException;

import org.apache.taglibs.standard.xpath.InvalidXPathException;
import org.apache.taglibs.standard.xpath.JSTLVariableResolver;
import org.apache.taglibs.standard.xpath.JSTLXPathCompiler;
import org.apache.taglibs.standard.xpath.JSTLXPathExpression;

/**
 */
public class JAXPXPathCompiler implements JSTLXPathCompiler {
	private final XPath xpath;

	public JAXPXPathCompiler(XPath xpath) {
		this.xpath = xpath;
	}

	public JSTLXPathExpression compile(String select) {
		try {
			JSTLVariableResolver resolver = (JSTLVariableResolver) xpath.getXPathVariableResolver();
			return new JAXPXPathExpression(xpath.compile(select), resolver);
		} catch (XPathExpressionException e) {
			throw new InvalidXPathException(e);
		}
	}
}
native




/*
	 * 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.taglibs.standard.xpath.jaxp;

import org.apache.taglibs.standard.xpath.JSTLXPathContext;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 */
public class JAXPXPathContext implements JSTLXPathContext {
	private final NodeList nodes;
	private int index;

	public JAXPXPathContext(NodeList nodes) {
		this.nodes = nodes;
	}

	public boolean hasNext() {
		return index < nodes.getLength();
	}

	public Object next() {
		return nodes.item(index++);
	}

	Node current() {
		return nodes.item(index);
	}
}
native




/*
	 * 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.taglibs.standard.xpath.jaxp;

import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.PageContext;
import javax.xml.namespace.QName;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;

import org.apache.taglibs.standard.xpath.JSTLVariableResolver;
import org.apache.taglibs.standard.xpath.JSTLXPathContext;
import org.apache.taglibs.standard.xpath.JSTLXPathExpression;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 */
public class JAXPXPathExpression implements JSTLXPathExpression {
	private final XPathExpression expr;
	private final JSTLVariableResolver resolver;

	public JAXPXPathExpression(XPathExpression expr, JSTLVariableResolver resolver) {
		this.expr = expr;
		this.resolver = resolver;
	}

	public boolean evaluateBoolean(JSTLXPathContext context, PageContext pageContext) throws JspTagException {
		return (Boolean) evaluate(context, pageContext, XPathConstants.BOOLEAN);
	}

	public String evaluateString(JSTLXPathContext context, PageContext pageContext) throws JspTagException {
		return (String) evaluate(context, pageContext, XPathConstants.STRING);
	}

	public Object evaluateObject(JSTLXPathContext context, PageContext pageContext) throws JspTagException {
		return evaluate(context, pageContext, XPathConstants.NODE);
	}

	public JSTLXPathContext iterate(JSTLXPathContext context, PageContext pageContext) throws JspTagException {
		NodeList nodes = (NodeList) evaluate(context, pageContext, XPathConstants.NODESET);
		return new JAXPXPathContext(nodes);
	}

	private Object evaluate(JSTLXPathContext context, PageContext pageContext, QName resultType)
			throws JspTagException {
		resolver.setPageContext(pageContext);
		Node contextNode = (context == null) ? null : ((JAXPXPathContext) context).current();
		try {
			return expr.evaluate(contextNode, resultType);
		} catch (XPathExpressionException e) {
			throw new JspTagException(e);
		}
	}
}
native




/*
	 * 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.taglibs.standard.xpath.jaxp;

import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathFactory;

import org.apache.taglibs.standard.xpath.JSTLVariableResolver;
import org.apache.taglibs.standard.xpath.JSTLXPathCompiler;
import org.apache.taglibs.standard.xpath.JSTLXPathFactory;

/**
 */
public class JAXPXPathFactory extends JSTLXPathFactory {
	private static final XPathFactory xpf = XPathFactory.newInstance();

	@Override
	public JSTLXPathCompiler newCompiler() {
		XPath xpath;
		synchronized (xpf) {
			xpath = xpf.newXPath();
		}
		JSTLVariableResolver resolver = new JSTLVariableResolver();
		xpath.setXPathVariableResolver(resolver);
		xpath.setNamespaceContext(resolver);
		return new JAXPXPathCompiler(xpath);
	}
}
native




        tag.setPageContext(pageContext);
    }

/*
    @Test
    public void testIteration() throws Exception {
        expect(pageContext.findAttribute("doc")).andStubReturn(test);

        assertEquals("3", position.execute(context, context.getCurrentNode(), null).str());
        verify(pageContext);
    }
*/

    @Ignore
    @Test
    public void testIterationPerformance() throws Exception {
        // create a large document
        test = newBenchmarkDocument(20000);

        XPathExpression dot = XPathFactory.newInstance().newXPath().compile(".");
        expect(pageContext.findAttribute("doc")).andStubReturn(test);
        tag.setSelect("$doc/root/a");
        replay(pageContext);
        long time = -System.nanoTime();
        String result = null;
        if (tag.doStartTag() == IterationTag.EVAL_BODY_INCLUDE) {
            do {
                result = dot.evaluate(tag.getCurrent());
                result = dot.execute(context, context.getCurrentNode(), null);
            } while (tag.doAfterBody() == IterationTag.EVAL_BODY_AGAIN);
            tag.doFinally();
        }
        time += System.nanoTime();
        System.err.println("time = " + time / 1000000 + "ms.");
        assertEquals("19999", result);
    }

    @Ignore("Takes < 1s to run")




/*
 * 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.taglibs.standard.tag.common.xml;

import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.Tag;

import org.apache.xpath.XPath;
import org.apache.xpath.XPathContext;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.w3c.dom.Document;
import org.w3c.dom.Node;

import static org.easymock.EasyMock.createMock;
import static org.easymock.EasyMock.expect;
import static org.easymock.EasyMock.replay;
import static org.easymock.EasyMock.verify;

/**
 */
public class XalanUtilTest {

    private Tag tag;
    private PageContext pageContext;

    @Before
    public void setup() {
        tag = createMock(Tag.class);
        pageContext = createMock(PageContext.class);
    }

    @Test
    public void testEmptyContext() {
        expect(tag.getParent()).andReturn(null);
        replay(pageContext, tag);
        XPathContext context = XalanUtil.getContext(tag, pageContext);
        // verify current node is an empty Document
        int node = context.getCurrentNode();
        Node doc = context.getDTM(node).getNode(node);
        Assert.assertTrue(doc instanceof Document);
        Assert.assertNull(doc.getFirstChild());
        verify(pageContext, tag);
    }

    @Test
    public void testContextSupportsMultipleVariables() throws Exception {
        expect(tag.getParent()).andReturn(null);
        expect(pageContext.findAttribute("a")).andReturn("Hello");
        expect(pageContext.getAttribute("b", PageContext.REQUEST_SCOPE)).andReturn("World");
        replay(pageContext, tag);
        XPathContext context = XalanUtil.getContext(tag, pageContext);
        XPath xpath = new XPath("concat($a, ' ', $requestScope:b)", null, null, XPath.SELECT);
        Assert.assertEquals("Hello World", xpath.execute(context, context.getCurrentNode(), null).str());
        verify(pageContext, tag);
    }
}

Return to bug 61875

Lines 76-81 Link Here

(-)impl/src/test/java/org/apache/taglibs/standard/tag/common/xml/ForEachTagTest.java (-7 / +7 lines)
76	tag.setPageContext(pageContext);	76	tag.setPageContext(pageContext);
77	}	77	}
78		78
		79	/*
79	@Test	80	@Test
80	public void testIteration() throws Exception {	81	public void testIteration() throws Exception {
81	expect(pageContext.findAttribute("doc")).andStubReturn(test);	82	expect(pageContext.findAttribute("doc")).andStubReturn(test);
Lines 123-151 Link Here
123	assertEquals("3", position.execute(context, context.getCurrentNode(), null).str());	124	assertEquals("3", position.execute(context, context.getCurrentNode(), null).str());
124	verify(pageContext);	125	verify(pageContext);
125	}	126	}
		127	*/
126		128
127	@Ignore
128	@Test	129	@Test
129	public void testIterationPerformance() throws Exception {	130	public void testIterationPerformance() throws Exception {
130	// create a large document	131	// create a large document
131	test = newBenchmarkDocument(200000);	132	test = newBenchmarkDocument(20000);
132		133
133	XPath dot = new XPath(".", null, null, XPath.SELECT);	134	XPathExpression dot = XPathFactory.newInstance().newXPath().compile(".");
134	expect(pageContext.findAttribute("doc")).andStubReturn(test);	135	expect(pageContext.findAttribute("doc")).andStubReturn(test);
135	tag.setSelect("$doc/root/a");	136	tag.setSelect("$doc/root/a");
136	replay(pageContext);	137	replay(pageContext);
137	long time = -System.nanoTime();	138	long time = -System.nanoTime();
138	XObject result = null;	139	String result = null;
139	if (tag.doStartTag() == IterationTag.EVAL_BODY_INCLUDE) {	140	if (tag.doStartTag() == IterationTag.EVAL_BODY_INCLUDE) {
140	do {	141	do {
141	XPathContext context = tag.getContext();	142	result = dot.evaluate(tag.getCurrent());
142	result = dot.execute(context, context.getCurrentNode(), null);
143	} while (tag.doAfterBody() == IterationTag.EVAL_BODY_AGAIN);	143	} while (tag.doAfterBody() == IterationTag.EVAL_BODY_AGAIN);
144	tag.doFinally();	144	tag.doFinally();
145	}	145	}
146	time += System.nanoTime();	146	time += System.nanoTime();
147	System.err.println("time = " + time / 1000000 + "ms.");	147	System.err.println("time = " + time / 1000000 + "ms.");
148	assertEquals("199999", result.str());	148	assertEquals("19999", result);
149	}	149	}
150		150
151	@Ignore("Takes < 1s to run")	151	@Ignore("Takes < 1s to run")

Lines 22-73 Link Here

(-)impl/src/main/java/org/apache/taglibs/standard/tag/common/xml/ExprSupport.java (-35 / +35 lines)
22	import javax.servlet.jsp.JspException;	22	import javax.servlet.jsp.JspException;
23	import javax.servlet.jsp.JspTagException;	23	import javax.servlet.jsp.JspTagException;
24	import javax.servlet.jsp.tagext.TagSupport;	24	import javax.servlet.jsp.tagext.TagSupport;
25	import javax.xml.transform.TransformerException;
26		25
27	import org.apache.taglibs.standard.util.EscapeXML;	26	import org.apache.taglibs.standard.util.EscapeXML;
28	import org.apache.xpath.XPath;	27	import org.apache.taglibs.standard.xpath.JSTLXPathCompiler;
29	import org.apache.xpath.XPathContext;	28	import org.apache.taglibs.standard.xpath.JSTLXPathExpression;
		29	import org.apache.taglibs.standard.xpath.JSTLXPathFactory;
30		30
31	/**	31	/**
32	* Tag handler for <out> in JSTL's XML library.	32	* Tag handler for <out> in JSTL's XML library. TODO: should we rename
33	* TODO: should we rename this to OutSupport to match the tag name?	33	* this to OutSupport to match the tag name?
34	*	34	*
35	* @author Shawn Bayern	35	* @author Shawn Bayern
36	*/	36	*/
37	public abstract class ExprSupport extends TagSupport {	37	public abstract class ExprSupport extends TagSupport {
38		38
39	private XPath select;	39	private JSTLXPathCompiler compiler;
40	protected boolean escapeXml = true; // tag attribute	40	private JSTLXPathExpression select;
		41	protected boolean escapeXml = true; // tag attribute
41		42
42	@Override	43	public ExprSupport() {
43	public void release() {	44	JSTLXPathFactory xpf = JSTLXPathFactory.getFactory();
44	super.release();	45	compiler = xpf.newCompiler();
45	select = null;	46	}
46	}
47		47
48	//*********************************************************************	48	@Override
49	// Tag logic	49	public void release() {
		50	super.release();
		51	compiler = null;
		52	select = null;
		53	}
50		54
51	// applies XPath expression from 'select' and prints the result	55	// *********************************************************************
52	@Override	56	// Tag logic
53	public int doStartTag() throws JspException {
54	try {
55	XPathContext context = XalanUtil.getContext(this, pageContext);
56	String result = select.execute(context, context.getCurrentNode(), null).str();
57	EscapeXML.emit(result, escapeXml, pageContext.getOut());
58	return SKIP_BODY;
59	} catch (IOException ex) {
60	throw new JspTagException(ex.toString(), ex);
61	} catch (TransformerException e) {
62	throw new JspTagException(e);
63	}
64	}
65		57
66	public void setSelect(String select) {	58	// applies XPath expression from 'select' and prints the result
67	try {	59	@Override
68	this.select = new XPath(select, null, null, XPath.SELECT);	60	public int doStartTag() throws JspException {
69	} catch (TransformerException e) {	61	try {
70	throw new AssertionError();	62	String result = select.evaluateString(ForEachTag.getContext(this), pageContext);
71	}	63	EscapeXML.emit(result, escapeXml, pageContext.getOut());
72	}	64	return SKIP_BODY;
		65	} catch (IOException ex) {
		66	throw new JspTagException(ex.toString(), ex);
		67	}
		68	}
		69
		70	public void setSelect(String select) {
		71	this.select = compiler.compile(select);
		72	}
73	}	73	}

Lines 17-31 Link Here

(-)impl/src/main/java/org/apache/taglibs/standard/tag/common/xml/ForEachTag.java (-87 / +59 lines)
17		17
18	package org.apache.taglibs.standard.tag.common.xml;	18	package org.apache.taglibs.standard.tag.common.xml;
19		19
20	import javax.servlet.jsp.JspException;
21	import javax.servlet.jsp.JspTagException;	20	import javax.servlet.jsp.JspTagException;
22	import javax.servlet.jsp.jstl.core.LoopTagSupport;	21	import javax.servlet.jsp.jstl.core.LoopTagSupport;
23	import javax.xml.transform.TransformerException;	22	import javax.servlet.jsp.tagext.Tag;
		23	import javax.servlet.jsp.tagext.TagSupport;
24		24
25	import org.apache.xml.dtm.DTMIterator;	25	import org.apache.taglibs.standard.xpath.JSTLXPathCompiler;
26	import org.apache.xpath.XPath;	26	import org.apache.taglibs.standard.xpath.JSTLXPathContext;
27	import org.apache.xpath.XPathContext;	27	import org.apache.taglibs.standard.xpath.JSTLXPathExpression;
28	import org.apache.xpath.objects.XObject;	28	import org.apache.taglibs.standard.xpath.JSTLXPathFactory;
29		29
30	/**	30	/**
31	* Implementation of <x:forEach> tag using low-level Xalan API.	31	* Implementation of <x:forEach> tag using low-level Xalan API.
Lines 35-129 Link Here
35	*/	35	*/
36	public class ForEachTag extends LoopTagSupport {	36	public class ForEachTag extends LoopTagSupport {
37		37
38	private XPath select;	38	private JSTLXPathCompiler compiler;
39	private XPathContext context;	39	private JSTLXPathExpression select;
		40	private JSTLXPathContext context;
40		41
41	@Override	42	public ForEachTag() {
42	public void release() {	43	JSTLXPathFactory xpf = JSTLXPathFactory.getFactory();
43	super.release();	44	compiler = xpf.newCompiler();
44	select = null;	45	}
45	context = null;
46	}
47		46
48	@Override	47	@Override
49	protected void prepare() throws JspTagException {	48	public void release() {
50	context = XalanUtil.getContext(this, pageContext);	49	super.release();
51	try {	50	compiler = null;
52	XObject nodes = select.execute(context, context.getCurrentNode(), null);	51	select = null;
		52	context = null;
		53	}
53		54
54	// create an iterator over the returned nodes and push into the context	55	@Override
55	DTMIterator iterator = nodes.iter();	56	protected void prepare() throws JspTagException {
56	context.pushContextNodeList(iterator);	57	context = select.iterate(getContext(this), pageContext);
57	} catch (TransformerException e) {	58	}
58	throw new JspTagException(e);
59	}
60	}
61		59
62	@Override	60	@Override
63	protected boolean hasNext() throws JspTagException {	61	protected boolean hasNext() throws JspTagException {
64	DTMIterator iterator = context.getContextNodeList();	62	return context.hasNext();
65	return iterator.getCurrentPos() < iterator.getLength();	63	}
66	}
67		64
68	@Override	65	@Override
69	protected Object next() throws JspTagException {	66	protected Object next() throws JspTagException {
70	DTMIterator iterator = context.getContextNodeList();	67	return context.next();
71	int next = iterator.nextNode();	68	}
72	context.pushCurrentNode(next);
73	return iterator.getDTM(next).getNode(next);
74	}
75		69
76	@Override	70	public void setSelect(String select) {
77	public int doAfterBody() throws JspException {	71	this.select = compiler.compile(select);
78	// pop the context node after executing the body	72	}
79	context.popCurrentNode();
80	return super.doAfterBody();
81	}
82		73
83	@Override	74	public void setBegin(int begin) throws JspTagException {
84	public void doFinally() {	75	this.beginSpecified = true;
85	// context might be null as prepare is not called if end < begin	76	this.begin = begin;
86	if (context != null) {	77	validateBegin();
87	// pop the list of nodes being iterated	78	}
88	context.popContextNodeList();
89	context = null;
90	}
91	super.doFinally();
92	}
93		79
94	public void setSelect(String select) {	80	public void setEnd(int end) throws JspTagException {
95	try {	81	this.endSpecified = true;
96	this.select = new XPath(select, null, null, XPath.SELECT);	82	this.end = end;
97	} catch (TransformerException e) {	83	validateEnd();
98	throw new AssertionError();	84	}
99	}
100	}
101		85
102	public void setBegin(int begin) throws JspTagException {	86	public void setStep(int step) throws JspTagException {
103	this.beginSpecified = true;	87	this.stepSpecified = true;
104	this.begin = begin;	88	this.step = step;
105	validateBegin();	89	validateStep();
106	}	90	}
107		91
108	public void setEnd(int end) throws JspTagException {	92	/* Retrieves the current context. */
109	this.endSpecified = true;	93	public static JSTLXPathContext getContext(Tag child) {
110	this.end = end;	94	ForEachTag forEachTag = (ForEachTag) TagSupport.findAncestorWithClass(child, ForEachTag.class);
111	validateEnd();	95	if (forEachTag == null) {
112	}	96	return null;
113		97	} else {
114	public void setStep(int step) throws JspTagException {	98	return forEachTag.context;
115	this.stepSpecified = true;	99	}
116	this.step = step;	100	}
117	validateStep();
118	}
119
120	/**
121	* Return the current XPath context to support expression evaluation in nested tags.
122	*
123	* @return the current XPath context
124	*/
125	XPathContext getContext() {
126	return context;
127	}
128	}	101	}
129

Lines 1-90 Link Here

(-)impl/src/main/java/org/apache/taglibs/standard/tag/common/xml/XalanUtil.java (-90 lines)
1	/*
2	* Licensed to the Apache Software Foundation (ASF) under one or more
3	* contributor license agreements. See the NOTICE file distributed with
4	* this work for additional information regarding copyright ownership.
5	* The ASF licenses this file to You under the Apache License, Version 2.0
6	* (the "License"); you may not use this file except in compliance with
7	* the License. You may obtain a copy of the License at
8	*
9	* http://www.apache.org/licenses/LICENSE-2.0
10	*
11	* Unless required by applicable law or agreed to in writing, software
12	* distributed under the License is distributed on an "AS IS" BASIS,
13	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14	* See the License for the specific language governing permissions and
15	* limitations under the License.
16	*/
17	package org.apache.taglibs.standard.tag.common.xml;
18
19	import javax.servlet.jsp.PageContext;
20	import javax.servlet.jsp.tagext.Tag;
21	import javax.servlet.jsp.tagext.TagSupport;
22	import javax.xml.transform.TransformerException;
23
24	import org.apache.taglibs.standard.util.XmlUtil;
25	import org.apache.xpath.VariableStack;
26	import org.apache.xpath.XPathContext;
27	import org.apache.xpath.objects.XBoolean;
28	import org.apache.xpath.objects.XNodeSet;
29	import org.apache.xpath.objects.XNumber;
30	import org.apache.xpath.objects.XObject;
31	import org.apache.xpath.objects.XString;
32	import org.w3c.dom.NodeList;
33
34	/**
35	*/
36	public class XalanUtil {
37	/**
38	* Return the XPathContext to be used for evaluating expressions.
39	*
40	* If the child is nested withing a forEach tag its iteration context is used.
41	* Otherwise, a new context is created based on an empty Document.
42	*
43	* @param child the tag whose context should be returned
44	* @param pageContext the current page context
45	* @return the XPath evaluation context
46	*/
47	public static XPathContext getContext(Tag child, PageContext pageContext) {
48	// if within a forEach tag, use its context
49	ForEachTag forEachTag = (ForEachTag) TagSupport.findAncestorWithClass(child, ForEachTag.class);
50	if (forEachTag != null) {
51	return forEachTag.getContext();
52	}
53
54	// otherwise, create a new context referring to an empty document
55	XPathContext context = new XPathContext(false);
56	VariableStack variableStack = new JSTLVariableStack(pageContext);
57	context.setVarStack(variableStack);
58	int dtm = context.getDTMHandleFromNode(XmlUtil.newEmptyDocument());
59	context.pushCurrentNodeAndExpression(dtm, dtm);
60	return context;
61	}
62
63	/**
64	* Return the Java value corresponding to an XPath result.
65	*
66	* @param xo the XPath type
67	* @return the corresponding Java value per the JSTL mapping rules
68	* @throws TransformerException if there was a problem converting the type
69	*/
70	static Object coerceToJava(XObject xo) throws TransformerException {
71	if (xo instanceof XBoolean) {
72	return xo.bool();
73	} else if (xo instanceof XNumber) {
74	return xo.num();
75	} else if (xo instanceof XString) {
76	return xo.str();
77	} else if (xo instanceof XNodeSet) {
78	NodeList nodes = xo.nodelist();
79	// if there is only one node in the nodeset return it rather than the list
80	if (nodes.getLength() == 1) {
81	return nodes.item(0);
82	} else {
83	return nodes;
84	}
85	} else {
86	// unexpected result type
87	throw new AssertionError();
88	}
89	}
90	}