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.model;
018
019import java.util.ArrayList;
020import java.util.List;
021import java.util.Map;
022
023import org.apache.commons.scxml2.ActionExecutionContext;
024import org.apache.commons.scxml2.Context;
025import org.apache.commons.scxml2.Evaluator;
026import org.apache.commons.scxml2.SCXMLExpressionException;
027
028/**
029 * A <code>ParamsContainer</code> represents an element in the SCXML
030 * document that may have one or more &lt;param/&gt; children which are used to
031 * produce payload for events or external communication.
032 */
033public abstract class ParamsContainer extends PayloadProvider {
034
035    /**
036     * The List of the params to be sent
037     */
038    private final List<Param> paramsList = new ArrayList<Param>();
039
040    /**
041     * Get the list of {@link Param}s.
042     *
043     * @return List The params list.
044     */
045    public List<Param> getParams() {
046        return paramsList;
047    }
048
049    /**
050     * Adds data to the payload data map based on the {@link Param}s of this {@link ParamsContainer}
051     * @param exctx The ActionExecutionContext
052     * @param payload the payload data map to be updated
053     * @throws ModelException if this action has not an EnterableState as parent
054     * @throws SCXMLExpressionException if a malformed or invalid expression is evaluated
055     * @see PayloadProvider#addToPayload(String, Object, java.util.Map)
056     */
057    protected void addParamsToPayload(ActionExecutionContext exctx, Map<String, Object> payload)
058            throws ModelException, SCXMLExpressionException {
059        if (!paramsList.isEmpty()) {
060            EnterableState parentState = getParentEnterableState();
061            Context ctx = exctx.getContext(parentState);
062            try {
063                ctx.setLocal(getNamespacesKey(), getNamespaces());
064                Evaluator evaluator = exctx.getEvaluator();
065                Object paramValue;
066                for (Param p : paramsList) {
067                    if (p.getExpr() != null) {
068                        paramValue = evaluator.eval(ctx, p.getExpr());
069                    }
070                    else if (p.getLocation() != null) {
071                        paramValue = evaluator.eval(ctx, p.getLocation());
072                    }
073                    else {
074                        // ignore invalid param definition
075                        continue;
076                    }
077                    addToPayload(p.getName(), paramValue, payload);
078                }
079            }
080            finally {
081                ctx.setLocal(getNamespacesKey(), null);
082            }
083        }
084    }
085}