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.javascript;
018
019import java.io.Serializable;
020
021import org.apache.commons.scxml2.Builtin;
022import org.apache.commons.scxml2.Context;
023import org.apache.commons.scxml2.SCXMLExpressionException;
024import org.apache.commons.scxml2.XPathBuiltin;
025
026/**
027 * Custom Javascript engine function providing the SCXML In() predicate and the Commons SCXML extensions
028 * for Data() and Location() to support XPath datamodel access.
029 */
030public class JSFunctions implements Serializable {
031
032    /**
033     * The context currently in use for evaluation.
034     */
035    private Context ctx;
036
037    /**
038     * Creates a new instance, wraps the context.
039     * @param ctx the context in use
040     */
041    public JSFunctions(Context ctx) {
042        this.ctx = ctx;
043    }
044
045    /**
046     * Provides the SCXML standard In() predicate for SCXML documents.
047     * @param state The State ID to compare with
048     * @return true if this state is currently active
049     */
050    public boolean In(final String state) {
051        return Builtin.isMember(ctx, state);
052    }
053
054    /**
055     * Provides the Commons SCXML Data() predicate extension for SCXML documents.
056     * @param expression the XPath expression
057     * @return the data matching the expression
058     */
059    public Object Data(String expression) throws SCXMLExpressionException {
060        return XPathBuiltin.eval(ctx, expression);
061    }
062
063    /**
064     * Provides the Commons SCXML Location() predicate extension for SCXML documents.
065     * @param expression the XPath expression
066     * @return the location matching the expression
067     */
068    public Object Location(String expression) throws SCXMLExpressionException {
069        return XPathBuiltin.evalLocation(ctx, expression);
070    }
071}