    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.model;
    018
    019    import java.util.Collection;
    020
    021    import org.apache.commons.scxml.Context;
    022    import org.apache.commons.scxml.ErrorReporter;
    023    import org.apache.commons.scxml.Evaluator;
    024    import org.apache.commons.scxml.EventDispatcher;
    025    import org.apache.commons.scxml.SCInstance;
    026    import org.apache.commons.scxml.SCXMLExpressionException;
    027
    028    /**
    029     * The class in this SCXML object model that corresponds to the
    030     * <log> SCXML element.
    031     *
    032     */
    033    public class Log extends Action {
    034
    035        /**
    036         * Serial version UID.
    037         */
    038        private static final long serialVersionUID = 1L;
    039
    040        /**
    041         * An expression evaluating to a string to be logged.
    042         */
    043        private String expr;
    044
    045        /**
    046         * An expression which returns string which may be used, for example,
    047         * to indicate the purpose of the log.
    048         */
    049        private String label;
    050
    051        /**
    052         * Constructor.
    053         */
    054        public Log() {
    055            super();
    056        }
    057
    058        /**
    059         * Get the log expression.
    060         *
    061         * @return Returns the expression.
    062         */
    063        public final String getExpr() {
    064            return expr;
    065        }
    066
    067        /**
    068         * Set the log expression.
    069         *
    070         * @param expr The expr to set.
    071         */
    072        public final void setExpr(final String expr) {
    073            this.expr = expr;
    074        }
    075
    076        /**
    077         * Get the log label.
    078         *
    079         * @return Returns the label.
    080         */
    081        public final String getLabel() {
    082            return label;
    083        }
    084
    085        /**
    086         * Set the log label.
    087         *
    088         * @param label The label to set.
    089         */
    090        public final void setLabel(final String label) {
    091            this.label = label;
    092        }
    093
    094        /**
    095         * {@inheritDoc}
    096         */
    097        public void execute(final EventDispatcher evtDispatcher,
    098                final ErrorReporter errRep, final SCInstance scInstance,
    099                final org.apache.commons.logging.Log appLog,
    100                final Collection derivedEvents)
    101        throws ModelException, SCXMLExpressionException {
    102            Context ctx = scInstance.getContext(getParentTransitionTarget());
    103            Evaluator eval = scInstance.getEvaluator();
    104            ctx.setLocal(getNamespacesKey(), getNamespaces());
    105            appLog.info(label + ": " + String.valueOf(eval.eval(ctx, expr)));
    106            ctx.setLocal(getNamespacesKey(), null);
    107        }
    108    }
    109