| /* |
| * $Id$ |
| * |
| * 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.template; |
| |
| import org.apache.tiles.Attribute; |
| import org.apache.tiles.AttributeContext; |
| import org.apache.tiles.Expression; |
| import org.apache.tiles.TilesContainer; |
| import org.apache.tiles.request.Request; |
| |
| /** |
| * The default implementation of AttributeResolver. |
| * |
| * @version $Rev$ $Date$ |
| * @since 2.2.0 |
| */ |
| public class DefaultAttributeResolver implements AttributeResolver { |
| |
| /** {@inheritDoc} */ |
| public Attribute computeAttribute(TilesContainer container, Attribute attribute, |
| String name, String role, boolean ignore, |
| Object defaultValue, String defaultValueRole, String defaultValueType, Request request) { |
| if (attribute == null) { |
| AttributeContext evaluatingContext = container |
| .getAttributeContext(request); |
| attribute = evaluatingContext.getAttribute(name); |
| if (attribute == null) { |
| attribute = computeDefaultAttribute(defaultValue, |
| defaultValueRole, defaultValueType); |
| if (attribute == null && !ignore) { |
| throw new NoSuchAttributeException("Attribute '" + name |
| + "' not found."); |
| } |
| } |
| } |
| if (attribute != null && role != null && !"".equals(role.trim())) { |
| attribute = new Attribute(attribute); |
| attribute.setRole(role); |
| } |
| return attribute; |
| } |
| |
| /** |
| * Computes the default attribute. |
| * |
| * @param defaultValue The default value of the attribute. |
| * @param defaultValueRole The default role of tha attribute. |
| * @param defaultValueType The default type of the attribute. |
| * @return The default attribute. |
| */ |
| private Attribute computeDefaultAttribute(Object defaultValue, |
| String defaultValueRole, String defaultValueType) { |
| Attribute attribute = null; |
| if (defaultValue != null) { |
| if (defaultValue instanceof Attribute) { |
| attribute = (Attribute) defaultValue; |
| } else if (defaultValue instanceof String) { |
| attribute = new Attribute(defaultValue, (Expression) null, |
| defaultValueRole, defaultValueType); |
| } |
| } |
| return attribute; |
| } |
| } |