FlyingSaucerInputRender.java

package com.wooki.services.export;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;

import javax.servlet.ServletContext;

import org.apache.tapestry5.ContentType;
import org.apache.tapestry5.EventConstants;
import org.apache.tapestry5.MarkupWriter;
import org.apache.tapestry5.SymbolConstants;
import org.apache.tapestry5.TapestryFilter;
import org.apache.tapestry5.internal.services.ArrayEventContext;
import org.apache.tapestry5.internal.services.HeartbeatImpl;
import org.apache.tapestry5.internal.services.RenderQueueImpl;
import org.apache.tapestry5.internal.services.RequestPageCache;
import org.apache.tapestry5.internal.structure.Page;
import org.apache.tapestry5.ioc.LoggerSource;
import org.apache.tapestry5.ioc.Registry;
import org.apache.tapestry5.ioc.internal.util.TapestryException;
import org.apache.tapestry5.ioc.services.SymbolSource;
import org.apache.tapestry5.ioc.services.TypeCoercer;
import org.apache.tapestry5.services.Environment;
import org.apache.tapestry5.services.Heartbeat;
import org.apache.tapestry5.services.MarkupWriterFactory;
import org.slf4j.Logger;
import org.springframework.web.context.ServletContextAware;

/**
 * Generate a representation to generate PDF through FlyingSaucer.
 * 
 * @author ccordenier
 */
public class FlyingSaucerInputRender implements ExportInputRenderer, ServletContextAware
{

    private ServletContext servletContext;

    private RequestPageCache pageCache;

    private TypeCoercer typeCoercer;

    private LoggerSource loggerSource;

    private MarkupWriterFactory factory;

    private Environment environment;

    private String encoding;

    private boolean initDone;

    /**
     * Init Tapestry registries and services.
     */
    private void init()
    {
        if (initDone) { return; }
        Registry tapestryRegistry = (Registry) this.servletContext
                .getAttribute(TapestryFilter.REGISTRY_CONTEXT_NAME);
        this.encoding = tapestryRegistry.getService(SymbolSource.class).valueForSymbol(
                SymbolConstants.CHARSET);
        this.environment = tapestryRegistry.getService(Environment.class);
        this.factory = tapestryRegistry.getService(MarkupWriterFactory.class);
        this.loggerSource = tapestryRegistry.getService(LoggerSource.class);
        this.pageCache = tapestryRegistry.getService(RequestPageCache.class);
        this.typeCoercer = tapestryRegistry.getService(TypeCoercer.class);
        this.initDone = true;
    }

    public InputStream exportBook(Long bookId)
    {

        this.init();

        MarkupWriter writer = factory.newMarkupWriter(new ContentType("text/xml", encoding));

        Page full = pageCache.get("book/fullFlyingSaucer");
        full.getRootElement().triggerContextEvent(
                EventConstants.ACTIVATE,
                new ArrayEventContext(typeCoercer, bookId),
                null);
        String name = "wooki.render." + full.getLogger().getName();
        Logger logger = loggerSource.getLogger(name);

        try
        {

            this.environment.push(Heartbeat.class, new HeartbeatImpl());
            RenderQueueImpl queue = new RenderQueueImpl(logger);
            queue.push(full.getRootElement());
            queue.run(writer);

            ByteArrayOutputStream dos = new ByteArrayOutputStream();
            PrintWriter printWriter = new PrintWriter(new OutputStreamWriter(dos, encoding));
            writer.toMarkup(printWriter);
            dos.flush();
            printWriter.flush();

            return new ByteArrayInputStream(dos.toByteArray());

        }
        catch (Exception ex)
        {
            logger.debug("Error while rendering book for FlyingSaucer", ex);
            throw new TapestryException("Error while rendering book for FlyingSaucer", ex);
        }
        finally
        {
            this.environment.pop(Heartbeat.class);
        }

    }

    public void setServletContext(ServletContext servletContext)
    {
        this.servletContext = servletContext;
    }
}