// Copyright 2007, 2008 The Apache Software Foundation
//
// 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 org.apache.tapestry5.internal.services;
import org.apache.tapestry5.MarkupWriter;
import org.apache.tapestry5.dom.Element;
import org.apache.tapestry5.internal.structure.Page;
import org.apache.tapestry5.ioc.LoggerSource;
import org.apache.tapestry5.ioc.ScopeConstants;
import org.apache.tapestry5.ioc.annotations.Scope;
import org.apache.tapestry5.ioc.internal.util.CollectionFactory;
import org.apache.tapestry5.ioc.internal.util.Defense;
import org.apache.tapestry5.ioc.util.Stack;
import org.apache.tapestry5.json.JSONObject;
import org.apache.tapestry5.runtime.RenderCommand;
import org.apache.tapestry5.services.PartialMarkupRenderer;
import org.apache.tapestry5.services.PartialMarkupRendererFilter;
import org.slf4j.Logger;
/**
* This services keeps track of the page being rendered and the root command for the partial render, it is therefore
* request/thread scoped. There's a filter pipeline around the rendering, and that gets to be stateless because this
* service, at the end of the pipeline, is stateful.
*/
@Scope(ScopeConstants.PERTHREAD)
public class PageRenderQueueImpl implements PageRenderQueue
{
private final LoggerSource loggerSource;
private Page page;
private RenderCommand rootCommand;
private final Stack<PartialMarkupRendererFilter> filters = CollectionFactory.newStack();
private static class Bridge implements PartialMarkupRenderer
{
private final PartialMarkupRendererFilter filter;
private final PartialMarkupRenderer delegate;
private Bridge(PartialMarkupRendererFilter filter, PartialMarkupRenderer delegate)
{
this.filter = filter;
this.delegate = delegate;
}
public void renderMarkup(MarkupWriter writer, JSONObject reply)
{
filter.renderMarkup(writer, reply, delegate);
}
}
public PageRenderQueueImpl(LoggerSource loggerSource)
{
this.loggerSource = loggerSource;
}
public void initializeForCompletePage(Page page)
{
this.page = page;
rootCommand = page.getRootElement();
}
public void setRenderingPage(Page page)
{
Defense.notNull(page, "page");
this.page = page;
}
public boolean isPartialRenderInitialized()
{
return rootCommand != null;
}
public void initializeForPartialPageRender(RenderCommand rootCommand)
{
Defense.notNull(rootCommand, "rootCommand");
if (page == null) throw new IllegalStateException("Page must be specified before root render command.");
this.rootCommand = rootCommand;
}
public RenderCommand getRootRenderCommand()
{
return rootCommand;
}
public Page getRenderingPage()
{
return page;
}
public void render(MarkupWriter writer)
{
String name = "tapestry.render." + page.getLogger().getName();
Logger logger = loggerSource.getLogger(name);
RenderQueueImpl queue = new RenderQueueImpl(logger);
queue.push(rootCommand);
// Run the queue until empty.
queue.run(writer);
}
public void addPartialMarkupRendererFilter(PartialMarkupRendererFilter filter)
{
Defense.notNull(filter, "filter");
filters.push(filter);
}
public void renderPartial(MarkupWriter writer, JSONObject reply)
{
PartialMarkupRenderer terminator = new PartialMarkupRenderer()
{
public void renderMarkup(MarkupWriter writer, JSONObject reply)
{
render(writer);
}
};
PartialMarkupRenderer delegate = terminator;
while (!filters.isEmpty())
{
PartialMarkupRendererFilter filter = filters.pop();
PartialMarkupRenderer bridge = new Bridge(filter, delegate);
delegate = bridge;
}
// The partial will quite often contain multiple elements (or just a block of plain text),
// so those must be enclosed in a root element.
Element root = writer.element("ajax-partial");
// The initialize methods will already have been invoked.
delegate.renderMarkup(writer, reply);
writer.end();
String content = root.getChildMarkup().trim();
reply.put("content", content);
}
}