| /* |
| * 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.Map; |
| import java.util.Set; |
| |
| import javax.xml.transform.TransformerException; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.commons.scxml.model.TransitionTarget; |
| import org.apache.xml.utils.PrefixResolver; |
| import org.apache.xpath.XPath; |
| import org.apache.xpath.XPathAPI; |
| import org.apache.xpath.XPathContext; |
| 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 allStates, |
| final String state) { |
| for (Iterator i = allStates.iterator(); i.hasNext();) { |
| TransitionTarget tt = (TransitionTarget) i.next(); |
| 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 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 { |
| 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); |
| } |
| result = XPathAPI.selectNodeList(dataNode, path); |
| } else { |
| XPathContext xpathSupport = new XPathContext(); |
| PrefixResolver prefixResolver = |
| new DataPrefixResolver(namespaces); |
| XPath xpath = new XPath(path, null, prefixResolver, |
| XPath.SELECT); |
| int ctxtNode = xpathSupport.getDTMHandleFromNode(dataNode); |
| result = xpath.execute(xpathSupport, ctxtNode, |
| prefixResolver).nodelist(); |
| } |
| } catch (TransformerException te) { |
| Log log = LogFactory.getLog(Builtin.class); |
| log.error(te.getMessage(), te); |
| 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 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 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; |
| } |
| |
| /** |
| * 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 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. |
| * |
| * @deprecated Use {@link #dataNode(Map,Object,String)} instead |
| */ |
| public static Node dataNode(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 { |
| result = XPathAPI.selectNodeList(dataNode, path); |
| } catch (TransformerException te) { |
| Log log = LogFactory.getLog(Builtin.class); |
| log.error(te.getMessage(), te); |
| 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 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 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. |
| * |
| * @deprecated Use {@link #data(Map,Object,String)} instead |
| */ |
| public static Object data(final Object data, final String path) { |
| Object retVal = null; |
| String strVal = SCXMLHelper.getNodeValue(dataNode(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; |
| } |
| |
| /** |
| * Prefix resolver for XPaths pointing to <data> nodes. |
| */ |
| private static class DataPrefixResolver implements PrefixResolver { |
| |
| /** Cached namespaces. */ |
| private Map namespaces; |
| |
| /** |
| * Constructor. |
| * @param namespaces The prefix to namespace URI map. |
| */ |
| private DataPrefixResolver(final Map namespaces) { |
| this.namespaces = namespaces; |
| } |
| |
| /** {@inheritDoc} */ |
| public String getNamespaceForPrefix(final String prefix) { |
| return (String) namespaces.get(prefix); |
| } |
| |
| /** {@inheritDoc} */ |
| public String getNamespaceForPrefix(final String prefix, |
| final Node nsContext) { |
| return (String) namespaces.get(prefix); |
| } |
| |
| /** {@inheritDoc} */ |
| public String getBaseIdentifier() { |
| return null; |
| } |
| |
| /** {@inheritDoc} */ |
| public boolean handlesNullPrefixes() { |
| return false; |
| } |
| |
| } |
| |
| } |
| |