| /* |
| * $Id$ |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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. |
| */ |
| |
| package org.apache.tiles.mvel; |
| |
| import java.util.Map; |
| |
| import org.apache.tiles.context.TilesRequestContext; |
| import org.apache.tiles.context.TilesRequestContextHolder; |
| import org.apache.tiles.evaluator.AbstractAttributeEvaluator; |
| import org.mvel2.MVEL; |
| import org.mvel2.integration.VariableResolverFactory; |
| |
| /** |
| * Allows to use MVEL as the language to evaluate attribute values. |
| * |
| * @version $Rev$ $Date$ |
| * @since 2.2.0 |
| */ |
| public class MVELAttributeEvaluator extends AbstractAttributeEvaluator { |
| |
| /** |
| * Holds the Tiles request context of the current thread. |
| */ |
| private TilesRequestContextHolder requestHolder; |
| |
| /** |
| * Resolves variables when starting from the root. |
| * |
| * @since 2.2.0 |
| */ |
| private VariableResolverFactory variableResolverFactory; |
| |
| /** |
| * Constructor. |
| * |
| * @param requestHolder The object that holds the Tiles request context of |
| * the current thread. |
| * @param variableResolverFactory The resolver factory to use. |
| * @since 2.2.0 |
| */ |
| public MVELAttributeEvaluator(TilesRequestContextHolder requestHolder, |
| VariableResolverFactory variableResolverFactory) { |
| this.requestHolder = requestHolder; |
| this.variableResolverFactory = variableResolverFactory; |
| } |
| |
| /** {@inheritDoc} */ |
| public void init(Map<String, String> initParameters) { |
| // Does nothing. |
| } |
| |
| /** {@inheritDoc} */ |
| public Object evaluate(String expression, TilesRequestContext request) { |
| if (expression == null) { |
| throw new IllegalArgumentException("The expression parameter cannot be null"); |
| } |
| requestHolder.setTilesRequestContext(request); |
| return MVEL.eval(expression, variableResolverFactory); |
| } |
| } |