// 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.tapestry.internal.services;
import org.apache.tapestry.MarkupWriter;
import org.apache.tapestry.dom.Element;
import org.apache.tapestry.internal.structure.Page;
import static org.apache.tapestry.ioc.IOCConstants.PERTHREAD_SCOPE;
import org.apache.tapestry.ioc.annotations.Scope;
import org.apache.tapestry.ioc.internal.util.Defense;
import org.apache.tapestry.json.JSONObject;
import org.apache.tapestry.runtime.RenderCommand;
/**
* 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(PERTHREAD_SCOPE)
public class PageRenderQueueImpl implements PageRenderQueue
{
private Page _page;
private RenderCommand _rootCommand;
public void initializeForCompletePage(Page page)
{
_page = page;
_rootCommand = page.getRootElement();
}
public void setRenderingPage(Page page)
{
Defense.notNull(page, "page");
_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.");
_rootCommand = rootCommand;
}
public RenderCommand getRootRenderCommand()
{
return _rootCommand;
}
public Page getRenderingPage()
{
return _page;
}
public void render(MarkupWriter writer)
{
RenderQueueImpl queue = new RenderQueueImpl(_page.getLogger());
queue.push(_rootCommand);
// Run the queue until empty.
queue.run(writer);
}
public void renderPartial(MarkupWriter writer, JSONObject reply)
{
// 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.
render(writer);
writer.end();
String content = root.getChildMarkup().trim();
reply.put("content", content);
}
}