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.semantics;
018
019 /**
020 * Errors reported by the default SCXMLSemantics implementation.
021 *
022 */
023 public class ErrorConstants {
024
025 /**
026 * Missing initial state for a composite state or for the scxml root.
027 *
028 * @see org.apache.commons.scxml.model.SCXML#getInitialState()
029 * @see org.apache.commons.scxml.model.State#getInitial()
030 */
031 public static final String NO_INITIAL = "NO_INITIAL";
032
033 /**
034 * An initial state for a composite state whose Transition does not.
035 * Map to a descendant of the composite state.
036 *
037 */
038 public static final String ILLEGAL_INITIAL = "ILLEGAL_INITIAL";
039
040 /**
041 * Unknown action - unsupported executable content. List of supported.
042 * actions: assign, cancel, elseif, else, if, log, send, var
043 */
044 public static final String UNKNOWN_ACTION = "UNKNOWN_ACTION";
045
046 /**
047 * Illegal state machine configuration.
048 * Either a parallel exists which does not have all its AND sub-states
049 * active or there are multiple enabled OR states on the same level.
050 */
051 public static final String ILLEGAL_CONFIG = "ILLEGAL_CONFIG";
052
053 /**
054 * Non-deterministic situation has occured - there are more than
055 * one enabled transitions in conflict.
056 *
057 * @deprecated Non deterministic behavior is now resolved using
058 * state heirarchy and document order priorities.
059 */
060 public static final String NON_DETERMINISTIC = "NON_DETERMINISTIC";
061
062 /**
063 * A variable referred to by assign name attribute is undefined.
064 */
065 public static final String UNDEFINED_VARIABLE = "UNDEFINED_VARIABLE";
066
067 /**
068 * An expression language error.
069 */
070 public static final String EXPRESSION_ERROR = "EXPRESSION_ERROR";
071
072 //---------------------------------------------- STATIC CONSTANTS ONLY
073
074 /**
075 * Discourage instantiation.
076 */
077 private ErrorConstants() {
078 super(); // humor checkstyle
079 }
080
081 }