StandardEvaluationContextFactory.java

package fr.acxio.tools.agia.expression;

/*
 * Copyright 2014 Acxio
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.util.Map;

import org.springframework.context.expression.MapAccessor;
import org.springframework.expression.spel.support.StandardEvaluationContext;

/**
 * <p>
 * Standard implementation of the context factory.
 * </p>
 * <p>
 * This factory allows to add common variables to the context. These variables
 * are not set at the data level, which allows to inject for example converters
 * into the context.
 * </p>
 * 
 * @author pcollardez
 *
 */
public class StandardEvaluationContextFactory implements EvaluationContextFactory {

    private Map<String, Object> commonObjects;

    public void setCommonObjects(Map<String, Object> sCommonObjects) {
        commonObjects = sCommonObjects;
    }

    @Override
    public StandardEvaluationContext createContext(String sName, Object sValue, StandardEvaluationContext sContext) {
        StandardEvaluationContext aContext = sContext;
        if (sContext == null) {
            aContext = new StandardEvaluationContext();
            if (commonObjects != null) {
                aContext.setVariables(commonObjects);
            }
            aContext.addPropertyAccessor(new MapAccessor());
        }
        aContext.setVariable(sName, sValue);
        return aContext;
    }

}