Problem generating pdfs with acts_as_flying_saucer_问答_开发者

I'm using the rails plugin acts_as_flying_saucer to generate a pdf, but the pdf doesn't work: i can save it ok, but when i try to open it i get this error message:

Unable to open document
File type SOR File (text/plain) is not supported

Here's my set up. I'm using rails 2.3.4 and the latest version of the acts_as_flying_saucer plugin. I have this route:

  map.all_help '/help/all.:format', :controller => "help", :action => "all"

which goes to this controller action:

class HelpController < ApplicationController
  acts_as_flying_saucer    

  def all
    respond_to do |format|
      format.html {
        render :action => "all", :layout => "help_pdf"
      }
      format.js
      format.pdf {
        render_pdf :template => 'help/all.html.erb', 
                   :layout => "help_pdf",
               :send_file => { :filename => "my-filename.pdf",  :type => "application/pdf"}      
      }
    end    
  end

end

and i also have this mime type defined:

 Mime::Type.register "application/pdf", :pdf

When i go to the page, /help/all.pdf, it generates a 0 byte pdf (which i can save ok) and i get the error message from the top of this post when i try to open it.

Going to the standard web page version of the page (/help/all) works fine. I thought maybe my java vm wasn't set up but it seems to be fine:

max-laptop:millionaire[subjects]$ java -version
java version "1.6.0_20"
Java(TM) SE Runtime Environment (build 1.6.0_20-b02)
Java HotSpot(TM) Client VM (build 16.3-b01, mixed mode, sharing)

I'm out of ideas at this point...grateful for any advice! max

EDIT: Just noticed that a bunch of error output is in my mongrel-running tab:

ERROR:  'Premature end of file.'
Exception in thread "main" org.xhtmlrenderer.util.XRRuntimeException: Can't load the XML resource (using TRaX transformer). org.xml.sax.SAXParseException: Premature end of file.
    at org.xhtmlrenderer.resource.XMLResource$XMLResourceBuilder.createXMLResource(XMLResource.java:191)
    at org.xhtmlrenderer.resource.XMLResource.load(XMLResource.java:71)
    at org.xhtmlrenderer.swing.NaiveUserAgent.getXMLResource(NaiveUserAgent.java:205)
    at org.xhtmlrenderer.pdf.ITextRenderer.loadDocument(ITextRenderer.java:102)
    at org.xhtmlrenderer.pdf.ITextRenderer.setDocument(ITextRenderer.java:106)
    at Xhtml2Pdf.main(Xhtml2Pdf.java:19)
Caused by: javax.xml.transform.TransformerException: org.xml.sax.SAXParseException: Premature end of file.
    at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:719)
    at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:313)
    at org.xhtmlrenderer.resource.XMLResource$XMLRes开发者_高级运维ourceBuilder.createXMLResource(XMLResource.java:189)
    ... 5 more
Caused by: org.xml.sax.SAXParseException: Premature end of file.
    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1231)
    at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transformIdentity(TransformerImpl.java:636)
    at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:707)
    ... 7 more

I'm wondering now if there's something wrong with the page i'm trying to convert to pdf. I ran the html version of the page past the w3c validator and the page validates ok. So now i'm stumped again...

EDIT 2: i think i'm getting closer now: looking in my log, i see

Rendering help/all.html.erb
html file: /tmp/ff4c8ff01d544500ea4bfea43e6108c1.html
Sending X-Sendfile header /tmp/ff4c8ff01d544500ea4bfea43e6108c1.pdf

So, i'd expect /tmp/ff4c8ff01d544500ea4bfea43e6108c1.html to have the html version of my page in it, but it's just a four line empty text file. No wonder flying saucer can't convert it. I don't know why it's saving an empty html file though.

EDIT 3: here's the html i'm currently trying to convert

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
  <head>
      <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
      <title>Help for Millionaire For Schools</title>
  </head>

  <body class="pdf">
        <div id="bgeffect"></div>        

    <div id="pageWrapper" class="mainHelpPages">

      <div id="helpContent">
        <div id="helpPane">
          <div class="inner">
            <p>Welcome to my pdf</p>
          </div>
        </div>
      </div>      
    </div> 

  </body>

</html>

Didn't you solve this problem a year ago by setting x_sendfile to false?

I solved this, it turned out to be really simple (and dumb). The problem was this: i was pointing to the layout i wanted to use in the normal railsy way,