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.xpath;
018
019import org.apache.commons.jxpath.Variables;
020import org.apache.commons.scxml2.Context;
021
022/**
023 * JXPath Variables mapping for SCXML Context
024 */
025public class ContextVariables implements Variables {
026
027    private final Context ctx;
028
029    public ContextVariables(Context ctx) {
030        this.ctx = ctx;
031    }
032
033    @Override
034    public boolean isDeclaredVariable(final String varName) {
035        return ctx.has(varName);
036    }
037
038    @Override
039    public Object getVariable(final String varName) {
040        return ctx.get(varName);
041    }
042
043    @Override
044    public void declareVariable(final String varName, final Object value) {
045        ctx.set(varName, value);
046    }
047
048    @Override
049    public void undeclareVariable(final String varName) {
050        if (ctx.has(varName)) {
051            Context cctx = ctx;
052            while (!cctx.hasLocal(varName)) {
053                cctx = cctx.getParent();
054                if (cctx == null) {
055                    return;
056                }
057            }
058            cctx.getVars().remove(varName);
059        }
060    }
061}