org.apache.tiles.template.DefaultAttributeResolver Maven / Gradle / Ivy
/*
* 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.api.Attribute;
import org.apache.tiles.api.AttributeContext;
import org.apache.tiles.api.TilesContainer;
import org.apache.tiles.request.Request;
/**
* The default implementation of AttributeResolver.
*
* @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, null, defaultValueRole, defaultValueType);
}
}
return attribute;
}
}