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.semantics;
018
019/**
020 * Errors reported by the default SCXMLSemantics implementation.
021 *
022 */
023public class ErrorConstants {
024
025    /**
026     * Missing initial state for a composite state or for the scxml root.
027     *
028     * @see org.apache.commons.scxml2.model.SCXML#getInitialTransition()
029     * @see org.apache.commons.scxml2.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     * A variable referred to by assign name attribute is undefined.
055     */
056    public static final String UNDEFINED_VARIABLE = "UNDEFINED_VARIABLE";
057
058    /**
059     * An expression language error.
060     */
061    public static final String EXPRESSION_ERROR = "EXPRESSION_ERROR";
062
063    /**
064     * An execution error.
065     */
066    public static final String EXECUTION_ERROR = "EXECUTION_ERROR";
067
068    //---------------------------------------------- STATIC CONSTANTS ONLY
069
070    /**
071     * Discourage instantiation.
072     */
073    private ErrorConstants() {
074        super(); // humor checkstyle
075    }
076
077}