src/main/java/org/apache/commons/scxml/Builtin.java - commons-scxml - 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.commons.scxml;

 import java.io.Serializable;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;

 import javax.xml.namespace.NamespaceContext;
 import javax.xml.xpath.XPath;
 import javax.xml.xpath.XPathConstants;
 import javax.xml.xpath.XPathExpressionException;
 import javax.xml.xpath.XPathFactory;

 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.commons.scxml.model.TransitionTarget;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;

 /**
  * Implementations of builtin functions defined by the SCXML
  * specification.
  *
  * The current version of the specification defines one builtin
  * predicate In()
  */
 public class Builtin implements Serializable {

     /**
      * Serial version UID.
      */
     private static final long serialVersionUID = 1L;

     /**
      * Implements the In() predicate for SCXML documents. The method
      * name chosen is different since &quot;in&quot; is a reserved token
      * in some expression languages.
      *
      * Does this state belong to the given Set of States.
      * Simple ID based comparator, assumes IDs are unique.
      *
      * @param allStates The Set of State objects to look in
      * @param state The State ID to compare with
      * @return Whether this State belongs to this Set
      */
     public static boolean isMember(final Set<TransitionTarget> allStates,
             final String state) {
         for (TransitionTarget tt : allStates) {
             if (state.equals(tt.getId())) {
                 return true;
             }
         }
         return false;
     }

     /**
      * Implements the Data() function for Commons SCXML documents, that
      * can be used to obtain a node from one of the XML data trees.
      * Manifests within "location" attribute of &lt;assign&gt; element,
      * for Commons JEXL and Commons EL based documents.
      *
      * @param namespaces The current document namespaces map at XPath location
      * @param data The context Node, though the method accepts an Object
      *             so error is reported by Commons SCXML, rather
      *             than the underlying expression language.
      * @param path The XPath expression.
      * @return The first node matching the path, or null if no nodes match.
      */
     public static Node dataNode(final Map<String, String> namespaces, final Object data,
             final String path) {
         if (data == null || !(data instanceof Node)) {
             Log log = LogFactory.getLog(Builtin.class);
             log.error("Data(): Cannot evaluate an XPath expression"
                 + " in the absence of a context Node, null returned");
             return null;
         }
         Node dataNode = (Node) data;
         NodeList result = null;
         try {
             XPath xpath = XPathFactory.newInstance().newXPath();
             if (namespaces == null || namespaces.size() == 0) {
                 Log log = LogFactory.getLog(Builtin.class);
                 if (log.isDebugEnabled()) {
                     log.debug("Turning off namespaced XPath evaluation since "
                         + "no namespace information is available for path: "
                         + path);
                 }
             } else {
                 xpath.setNamespaceContext(new ExpressionNSContext(namespaces));
             }
             result = (NodeList) xpath.evaluate(path, dataNode,
                 XPathConstants.NODESET);
         } catch (XPathExpressionException xee) {
             Log log = LogFactory.getLog(Builtin.class);
             log.error(xee.getMessage(), xee);
             return null;
         }
         int length = result.getLength();
         if (length == 0) {
             Log log = LogFactory.getLog(Builtin.class);
             log.warn("Data(): No nodes matching the XPath expression \""
                 + path + "\", returning null");
             return null;
         } else {
             if (length > 1) {
                 Log log = LogFactory.getLog(Builtin.class);
                 log.warn("Data(): Multiple (" + length + ") nodes matching XPath expression \""
                     + path + "\", returning first");
             }
             return result.item(0);
         }
     }

     /**
      * A variant of the Data() function for Commons SCXML documents,
      * coerced to a Double, a Long or a String, whichever succeeds,
      * in that order.
      * Manifests within rvalue expressions in the document,
      * for Commons JEXL and Commons EL based documents..
      *
      * @param namespaces The current document namespaces map at XPath location
      * @param data The context Node, though the method accepts an Object
      *             so error is reported by Commons SCXML, rather
      *             than the underlying expression language.
      * @param path The XPath expression.
      * @return The first node matching the path, coerced to a String, or null
      *         if no nodes match.
      */
     public static Object data(final Map<String, String> namespaces, final Object data,
             final String path) {
         Object retVal = null;
         String strVal = SCXMLHelper.getNodeValue(dataNode(namespaces,
             data, path));
         // try as a double
         try {
             double d = Double.parseDouble(strVal);
             retVal = new Double(d);
         } catch (NumberFormatException notADouble) {
             // else as a long
             try {
                 long l = Long.parseLong(strVal);
                 retVal = new Long(l);
             } catch (NumberFormatException notALong) {
                 // fallback to string
                 retVal = strVal;
             }
         }
         return retVal;
     }

     /**
      * XPath {@link NamespaceContext} for Commons SCXML expressions.
      *
      * <b>Code duplication:</b> Also in XPathEvaluator.java. Class is not
      * meant to be part of any public API and will be removed when parser
      * is no longer using Commons Digester.
      */
     private static final class ExpressionNSContext
     implements Serializable, NamespaceContext {

         /** Serial version UID. */
         private static final long serialVersionUID = 8620558582288851315L;
         /** Map supplied by digester. */
         private final Map<String, String> namespaces;

         /**
          * Constructor.
          *
          * @param namespaces The current namespace map.
          */
         ExpressionNSContext(final Map<String, String> namespaces) {
             this.namespaces = namespaces;
         }

         /**
          * @see NamespaceContext#getNamespaceURI(String)
          */
         @Override
         public String getNamespaceURI(final String prefix) {
             return namespaces.get(prefix);
         }

         /**
          * @see NamespaceContext#getPrefix(String)
          *
          * First matching key in iteration order is returned, and the
          * iteration order depends on the underlying <code>namespaces</code>
          * {@link Map} implementation.
          */
         @Override
         public String getPrefix(final String namespaceURI) {
             return (String) getKeys(namespaceURI, true);
         }

         /**
          * @see NamespaceContext#getPrefixes(String)
          *
          * The iteration order depends on the underlying <code>namespaces</code>
          * {@link Map} implementation.
          */
         @Override
         @SuppressWarnings("unchecked")
         public Iterator<String> getPrefixes(final String namespaceURI) {
             return (Iterator<String>) getKeys(namespaceURI, false);
         }

         /**
          * Get prefix key(s) for given namespaceURI value.
          *
          * If <code>one</code>, first matching key in iteration order is
          * returned, and the iteration order depends on the underlying
          * <code>namespaces</code> {@link Map} implementation.
          * Otherwise, an iterator to all matching keys is returned.
          *
          * @param value The value whose key is required
          * @param one At most one matching key is returned
          * @return The required prefix key(s)
          */
         private Object getKeys(final String value, final boolean one) {
             List<String> prefixes = new LinkedList<String>();
             if (namespaces.containsValue(value)) {
                 for (Map.Entry<String, String> entry : namespaces.entrySet()) {
                     String v = entry.getValue();
                     if ((value == null && v == null) ||
                             (value != null && value.equals(v))) {
                         String prefix = entry.getKey();
                         if (one) {
                             return prefix;
                         } else {
                             prefixes.add(prefix);
                         }
                     }
                 }
             }
             return one ? null : prefixes.iterator();
         }

     }

 }
	/*
	* 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.commons.scxml;

	import java.io.Serializable;
	import java.util.Iterator;
	import java.util.LinkedList;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;

	import javax.xml.namespace.NamespaceContext;
	import javax.xml.xpath.XPath;
	import javax.xml.xpath.XPathConstants;
	import javax.xml.xpath.XPathExpressionException;
	import javax.xml.xpath.XPathFactory;

	import org.apache.commons.logging.Log;
	import org.apache.commons.logging.LogFactory;
	import org.apache.commons.scxml.model.TransitionTarget;
	import org.w3c.dom.Node;
	import org.w3c.dom.NodeList;

	/**
	* Implementations of builtin functions defined by the SCXML
	* specification.
	*
	* The current version of the specification defines one builtin
	* predicate In()
	*/
	public class Builtin implements Serializable {

	/**
	* Serial version UID.
	*/
	private static final long serialVersionUID = 1L;

	/**
	* Implements the In() predicate for SCXML documents. The method
	* name chosen is different since "in" is a reserved token
	* in some expression languages.
	*
	* Does this state belong to the given Set of States.
	* Simple ID based comparator, assumes IDs are unique.
	*
	* @param allStates The Set of State objects to look in
	* @param state The State ID to compare with
	* @return Whether this State belongs to this Set
	*/
	public static boolean isMember(final Set<TransitionTarget> allStates,
	final String state) {
	for (TransitionTarget tt : allStates) {
	if (state.equals(tt.getId())) {
	return true;
	}
	}
	return false;
	}

	/**
	* Implements the Data() function for Commons SCXML documents, that
	* can be used to obtain a node from one of the XML data trees.
	* Manifests within "location" attribute of <assign> element,
	* for Commons JEXL and Commons EL based documents.
	*
	* @param namespaces The current document namespaces map at XPath location
	* @param data The context Node, though the method accepts an Object
	* so error is reported by Commons SCXML, rather
	* than the underlying expression language.
	* @param path The XPath expression.
	* @return The first node matching the path, or null if no nodes match.
	*/
	public static Node dataNode(final Map<String, String> namespaces, final Object data,
	final String path) {
	if (data == null \|\| !(data instanceof Node)) {
	Log log = LogFactory.getLog(Builtin.class);
	log.error("Data(): Cannot evaluate an XPath expression"
	+ " in the absence of a context Node, null returned");
	return null;
	}
	Node dataNode = (Node) data;
	NodeList result = null;
	try {
	XPath xpath = XPathFactory.newInstance().newXPath();
	if (namespaces == null \|\| namespaces.size() == 0) {
	Log log = LogFactory.getLog(Builtin.class);
	if (log.isDebugEnabled()) {
	log.debug("Turning off namespaced XPath evaluation since "
	+ "no namespace information is available for path: "
	+ path);
	}
	} else {
	xpath.setNamespaceContext(new ExpressionNSContext(namespaces));
	}
	result = (NodeList) xpath.evaluate(path, dataNode,
	XPathConstants.NODESET);
	} catch (XPathExpressionException xee) {
	Log log = LogFactory.getLog(Builtin.class);
	log.error(xee.getMessage(), xee);
	return null;
	}
	int length = result.getLength();
	if (length == 0) {
	Log log = LogFactory.getLog(Builtin.class);
	log.warn("Data(): No nodes matching the XPath expression \""
	+ path + "\", returning null");
	return null;
	} else {
	if (length > 1) {
	Log log = LogFactory.getLog(Builtin.class);
	log.warn("Data(): Multiple (" + length + ") nodes matching XPath expression \""
	+ path + "\", returning first");
	}
	return result.item(0);
	}
	}

	/**
	* A variant of the Data() function for Commons SCXML documents,
	* coerced to a Double, a Long or a String, whichever succeeds,
	* in that order.
	* Manifests within rvalue expressions in the document,
	* for Commons JEXL and Commons EL based documents..
	*
	* @param namespaces The current document namespaces map at XPath location
	* @param data The context Node, though the method accepts an Object
	* so error is reported by Commons SCXML, rather
	* than the underlying expression language.
	* @param path The XPath expression.
	* @return The first node matching the path, coerced to a String, or null
	* if no nodes match.
	*/
	public static Object data(final Map<String, String> namespaces, final Object data,
	final String path) {
	Object retVal = null;
	String strVal = SCXMLHelper.getNodeValue(dataNode(namespaces,
	data, path));
	// try as a double
	try {
	double d = Double.parseDouble(strVal);
	retVal = new Double(d);
	} catch (NumberFormatException notADouble) {
	// else as a long
	try {
	long l = Long.parseLong(strVal);
	retVal = new Long(l);
	} catch (NumberFormatException notALong) {
	// fallback to string
	retVal = strVal;
	}
	}
	return retVal;
	}

	/**
	* XPath {@link NamespaceContext} for Commons SCXML expressions.
	*
	* <b>Code duplication:</b> Also in XPathEvaluator.java. Class is not
	* meant to be part of any public API and will be removed when parser
	* is no longer using Commons Digester.
	*/
	private static final class ExpressionNSContext
	implements Serializable, NamespaceContext {

	/** Serial version UID. */
	private static final long serialVersionUID = 8620558582288851315L;
	/** Map supplied by digester. */
	private final Map<String, String> namespaces;

	/**
	* Constructor.
	*
	* @param namespaces The current namespace map.
	*/
	ExpressionNSContext(final Map<String, String> namespaces) {
	this.namespaces = namespaces;
	}

	/**
	* @see NamespaceContext#getNamespaceURI(String)
	*/
	@Override
	public String getNamespaceURI(final String prefix) {
	return namespaces.get(prefix);
	}

	/**
	* @see NamespaceContext#getPrefix(String)
	*
	* First matching key in iteration order is returned, and the
	* iteration order depends on the underlying <code>namespaces</code>
	* {@link Map} implementation.
	*/
	@Override
	public String getPrefix(final String namespaceURI) {
	return (String) getKeys(namespaceURI, true);
	}

	/**
	* @see NamespaceContext#getPrefixes(String)
	*
	* The iteration order depends on the underlying <code>namespaces</code>
	* {@link Map} implementation.
	*/
	@Override
	@SuppressWarnings("unchecked")
	public Iterator<String> getPrefixes(final String namespaceURI) {
	return (Iterator<String>) getKeys(namespaceURI, false);
	}

	/**
	* Get prefix key(s) for given namespaceURI value.
	*
	* If <code>one</code>, first matching key in iteration order is
	* returned, and the iteration order depends on the underlying
	* <code>namespaces</code> {@link Map} implementation.
	* Otherwise, an iterator to all matching keys is returned.
	*
	* @param value The value whose key is required
	* @param one At most one matching key is returned
	* @return The required prefix key(s)
	*/
	private Object getKeys(final String value, final boolean one) {
	List<String> prefixes = new LinkedList<String>();
	if (namespaces.containsValue(value)) {
	for (Map.Entry<String, String> entry : namespaces.entrySet()) {
	String v = entry.getValue();
	if ((value == null && v == null) \|\|
	(value != null && value.equals(v))) {
	String prefix = entry.getKey();
	if (one) {
	return prefix;
	} else {
	prefixes.add(prefix);
	}
	}
	}
	}
	return one ? null : prefixes.iterator();
	}

	}

	}