23 April 2008 Export, FO, Handler, HowTo, nFop, PDF, Xml, XSLT Robert Muehsig

My college Oliver Guhr wroted a nice blogpost about PDF creation with nFop. The post is in german - but just scroll down to download the soure code.

Today I wanted to show you, how you could create a PDF by just clicking a link on a webpage. Oliver helped me again and wrote the source code of this blog post:

First step: J# dlls

I only have Visual Studio 2008 installed - without the Visual J# library - the "vjslib.dll". You need this dll for nFop. If you don´t have this dll, just download it here: Visual J# Redistributable Packages

The solution: A generic handler

It´s a bit tricky to write the PDF content in the context - here is the complete source code from my ASHX:

<%@ WebHandler Language="C#" Class="PdfHandler" %>

using System;
using System.Data;
using System.Web;
using System.Collections;
using System.Web.Services;
using System.Web.Services.Protocols;
using java.io;
using org.xml.sax;
using org.apache.fop.apps;
using System.IO;


[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public class PdfHandler : IHttpHandler
{

    public void ProcessRequest(HttpContext context)
    {
        context.Response.ContentType = "application/pdf";                     
        FileInputStream input = new FileInputStream(context.Request.PhysicalApplicationPath+"helloworld.fo");
        InputSource source = new InputSource(input);

        java.io.ByteArrayOutputStream output = new ByteArrayOutputStream();

        Driver driver = new Driver(source, output);
        driver.setRenderer(Driver.RENDER_PDF);
        driver.run();
        output.close();

        sbyte[] Pdf = output.toByteArray();
        BinaryWriter bw = new BinaryWriter(context.Response.OutputStream);           
        for (int i = 0; i < Pdf.Length; i++)
        {
            bw.Write(Pdf[i]);
        }

        bw.Close();
    }

    public bool IsReusable
    {
        get
        {
            return false;
        }
    }
}


A look into the solution explorer:

image

The helloworld.fo:

<?xml version="1.0" encoding="utf-8"?>
<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
  <fo:layout-master-set>
    <fo:simple-page-master  master-name="A4"³
                            page-width="210mm" page-height="297mm">
      <fo:region-body region-name="xsl-region-body"  margin="2cm"/>
    </fo:simple-page-master>
  </fo:layout-master-set>

  <fo:page-sequence  master-reference="A4"³>
    <!- (in Versionen <2.0 "master-name") ->
    <fo:flow flow-name="xsl-region-body">
      <fo:block>Hallo Welt!</fo:block>   
    </fo:flow>
  </fo:page-sequence>

</fo:root>

Now you can create the "helloworld" PDF by just clicking this link:
http://localhost:56602/Pdf/PdfHandler.ashx

Easy :)

[ Download Democode ]


Written by Robert Muehsig

Software Developer - from Dresden, Germany, now living & working in Switzerland. Microsoft MVP & Web Geek.
Other Projects: KnowYourStack.com | ExpensiveMeeting | EinKofferVollerReisen.de

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