001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.commons.scxml.env;
018
019 import java.util.Iterator;
020 import java.util.LinkedList;
021
022 import org.apache.commons.scxml.model.Transition;
023 import org.apache.commons.scxml.model.TransitionTarget;
024
025 /**
026 * Helper methods for Commons SCXML logging.
027 *
028 */
029 public final class LogUtils {
030
031 /**
032 * Create a human readable log view of this transition.
033 *
034 * @param from The source TransitionTarget
035 * @param to The destination TransitionTarget
036 * @param transition The Transition that is taken
037 * @return String The human readable log entry
038 */
039 public static String transToString(final TransitionTarget from,
040 final TransitionTarget to, final Transition transition) {
041 StringBuffer buf = new StringBuffer("transition (");
042 buf.append("event = ").append(transition.getEvent());
043 buf.append(", cond = ").append(transition.getCond());
044 buf.append(", from = ").append(getTTPath(from));
045 buf.append(", to = ").append(getTTPath(to));
046 buf.append(')');
047 return buf.toString();
048 }
049
050 /**
051 * Write out this TransitionTarget location in a XPath style format.
052 *
053 * @param tt The TransitionTarget whose "path" is to needed
054 * @return String The XPath style location of the TransitionTarget within
055 * the SCXML document
056 */
057 public static String getTTPath(final TransitionTarget tt) {
058 TransitionTarget parent = tt.getParent();
059 if (parent == null) {
060 return "/" + tt.getId();
061 } else {
062 LinkedList pathElements = new LinkedList();
063 pathElements.addFirst(tt);
064 while (parent != null) {
065 pathElements.addFirst(parent);
066 parent = parent.getParent();
067 }
068 StringBuffer names = new StringBuffer();
069 for (Iterator i = pathElements.iterator(); i.hasNext();) {
070 TransitionTarget pathElement = (TransitionTarget) i.next();
071 names.append('/').append(pathElement.getId());
072 }
073 return names.toString();
074 }
075 }
076
077 /**
078 * Discourage instantiation since this is a utility class.
079 */
080 private LogUtils() {
081 super();
082 }
083
084 }