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 */
017package org.apache.commons.scxml2.env;
018
019import org.apache.commons.scxml2.model.Transition;
020import org.apache.commons.scxml2.model.TransitionTarget;
021
022/**
023 * Helper methods for Commons SCXML logging.
024 *
025 */
026public final class LogUtils {
027
028    /**
029     * Create a human readable log view of this transition.
030     *
031     * @param from The source TransitionTarget
032     * @param to The destination TransitionTarget
033     * @param transition The Transition that is taken
034     * @return String The human readable log entry
035     */
036    public static String transToString(final TransitionTarget from,
037            final TransitionTarget to, final Transition transition, String event) {
038        StringBuffer buf = new StringBuffer("(");
039        buf.append("event = ").append(event);
040        buf.append(", cond = ").append(transition.getCond());
041        buf.append(", from = ").append(getTTPath(from));
042        buf.append(", to = ").append(getTTPath(to));
043        buf.append(')');
044        return buf.toString();
045    }
046
047    /**
048     * Write out this TransitionTarget location in a XPath style format.
049     *
050     * @param tt The TransitionTarget whose "path" is to needed
051     * @return String The XPath style location of the TransitionTarget within
052     *                the SCXML document
053     */
054    public static String getTTPath(final TransitionTarget tt) {
055        StringBuilder sb = new StringBuilder("/");
056        for (int i = 0; i < tt.getNumberOfAncestors(); i++) {
057            sb.append(tt.getAncestor(i).getId());
058            sb.append("/");
059        }
060        sb.append(tt.getId());
061        return sb.toString();
062    }
063
064    /**
065     * Discourage instantiation since this is a utility class.
066     */
067    private LogUtils() {
068        super();
069    }
070
071}