/*
* Copyright 2011-2013 HTTL Team.
*
* 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.
*/
package httl.spi.interceptors;
import httl.Context;
import httl.Engine;
import httl.Template;
import httl.spi.Interceptor;
import httl.spi.Listener;
import httl.spi.methods.FileMethod;
import httl.spi.translators.templates.ListenerTemplate;
import httl.util.Optional;
import httl.util.StringUtils;
import httl.util.UrlUtils;
import java.io.IOException;
import java.text.ParseException;
/**
* Extends Interceptor. (SPI, Singleton, ThreadSafe)
*
* @see httl.spi.translators.CompiledTranslator#setInterceptor(Interceptor)
* @see httl.spi.translators.InterpretedTranslator#setInterceptor(Interceptor)
*
* @author Liang Fei (liangfei0201 AT gmail DOT com)
*/
public class ExtendsInterceptor extends FirstInterceptor {
private final FileMethod fileMethod = new FileMethod();
private Engine engine;
private String extendsDirectory;
private String extendsDefault;
private String extendsNested;
private String extendsVariable;
/**
* httl.properties: engine=httl.spi.engines.DefaultEngine
*/
public void setEngine(Engine engine) {
this.engine = engine;
fileMethod.setEngine(engine);
}
/**
* httl.properties: extends.directory=layouts
*/
public void setExtendsDirectory(String extendsDirectory) {
this.extendsDirectory = UrlUtils.cleanDirectory(extendsDirectory);
if ("/".equals(this.extendsDirectory)) {
this.extendsDirectory = null;
}
fileMethod.setExtendsDirectory(extendsDirectory);
}
/**
* httl.properties: extends.default=default.httl
*/
@Optional
public void setExtendsDefault(String extendsDefault) {
this.extendsDefault = extendsDefault;
}
/**
* httl.properties: extends.variable=layout
*/
@Optional
public void setExtendsVariable(String extendsVariable) {
this.extendsVariable = extendsVariable;
}
/**
* httl.properties: extends.nested=nested
*/
public void setExtendsNested(String extendsNested) {
this.extendsNested = extendsNested;
}
public void doRender(Context context, Listener listener) throws IOException, ParseException {
String extendsName = null;
// extends.varibale=layout
// 如果上下文中有指定要继承的模板，则自动继承它。
// 注意：此模板是从继承模板目录中查找的，即实际为：template.directory + extends.directory + context.get(extends.varibale)
if (StringUtils.isNotEmpty(extendsVariable)) {
extendsName = (String) context.get(extendsVariable);
}
// extends.default=default.httl
// 如果默认模板存在，则继承默认模板。
// 注意：默认模板是从继承模板目录中查找的，即实际为：template.directory + extends.directory + extends.default
Template template = context.getTemplate();
if (StringUtils.isEmpty(extendsName) && StringUtils.isNotEmpty(extendsDefault)) {
String templateName = template.getName();
String name = UrlUtils.relativeUrl(extendsDefault, templateName);
if (StringUtils.isNotEmpty(extendsDirectory)) {
name = extendsDirectory + name;
}
if (! name.equals(templateName) && engine.hasResource(name)) {
extendsName = extendsDefault;
}
}
if (StringUtils.isNotEmpty(extendsName)) {
// extends.nested=nested
Object oldNested = null;
if (StringUtils.isNotEmpty(extendsNested)) {
oldNested = context.put(extendsNested, new ListenerTemplate(template, listener));
}
try {
Template extend = fileMethod.$extends(extendsName, template.getLocale(), template.getEncoding());
extend.render(context.getOut());
} finally {
if (StringUtils.isNotEmpty(extendsNested)) {
if (oldNested != null) {
context.put(extendsNested, oldNested);
} else {
context.remove(extendsNested);
}
}
}
} else {
listener.render(context);
}
}
}