As I tried to break it down to send you an actual code sample so you could see how the ugly code works, which was doing a transform on the client, and see what I was trying to do with transforming on the server which wasn't working, I started to examine each object and each step and figure out it's purpose. I ultimately realized that while my attempt at transforming the document on the server to load in the client PreviewPanel wasn't getting any errors (or output), it was also missing some things and had some things which weren't even doing anything. I've debugged the disconnect and it works!
My print portion of the program is using the Fop class to connect everything. I create the Fop with a ByteArrayOutputStream. Then I create a SAXResult object using the Fop getDefaultHandler method. Then I pass that SAXResult as the output to the javax transform method and the Fop class links it back to put a finished document in the ByteArrayOutputStream. I get the bytes from that output stream to generate a ByteArrayInputStream which I pass as input to create a PDDocument object with the pdfbox project, which I can either save as a PDF file or pass to the printer using java's PrinterJob. Since that output is in byte[] form in between the output stream and the input stream, I can either create that PDF on the server or copy the bytes down to create it directly on the client. Now we get to how that all ties together. I checked the PreviewPanel and saw there is no way to pass the finished document. That document goes through the Renderer. I looked at AWTRenderer and saw the document can be passed in using the Renderable class. I couldn't figure out how to connect this to the Fop class which is generating the finished document in the previously described print portion, then I figured out this is just a convenience class to connect the transforming to the rendering. What I needed in order to use the Renderable class was the intermediate stage. I replaced the SAXResult output for the transform on the server with a StreamResult which can be tied to a file. This generated the FO file which is the transformed, unrendered document. The Java File is serializable, so I just copied that to the client for input to the cli InputHandler. Then I execute the InputHandler's renderTo and pass it to the AWTRenderer's setRenderable, and I have a finished document for the PreviewPanel. I still have to create the FopFactory, the FOUserAgent, and the AWTRenderer on the client, but leaving the XML, XSL, and the Transformer on the server saves a lot. -----Original Message----- From: Jeremias Maerki [mailto:d...@jeremias-maerki.ch] Sent: Friday, November 19, 2010 3:41 AM To: fop-users@xmlgraphics.apache.org Subject: Re: Renderable I think you have two options: 1. Create a bitmap (with PNGDocumentHandler (image/png)) on the server and send that to the client. But you will likely have to produce your own viewer and cannot reuse FOP's preview dialog. 2. Generate the IF XML format on the server, send that to the client and use the org.apache.fop.cli.IFInputHandler to render the IF XML file in FOP's preview dialog. That at least does the layout part on the server, but if your document contains SVGs or barcodes, that part will still be processed on the client-side FOP. Please note that FOP's Renderable class is not the same as AWT's Renderable. And FOP has multiple implementations of it own Renderable interface in the org.apache.fop.cli package. If you want to off-load as much as possible to the server, you should pursue option 1. On 17.11.2010 17:16:08 Eric Douglas wrote: > I'm creating an object of type > org.apache.fop.render.awt.viewer.PreviewPanel. > The constructor is (FOUserAgent foUserAgent, Renderable renderable, > AWTRenderer renderer). > I'm running a client-server program in webstart. > Of course the PreviewPanel must be created as a client object. > This works if I pass a null for Renderable, but also seems to require > that I tie my AWTRenderer to a client Fop object to do a client > transform. > The transform runs a lot faster on the server. > I was wondering if I can do the transform on the server and just pass > the result into the client. > That appears to be the purpose of the Renderable class. > I don't see any FOP classes which return or implement a Renderable. > How do I generate one? Jeremias Maerki --------------------------------------------------------------------- To unsubscribe, e-mail: fop-users-unsubscr...@xmlgraphics.apache.org For additional commands, e-mail: fop-users-h...@xmlgraphics.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: fop-users-unsubscr...@xmlgraphics.apache.org For additional commands, e-mail: fop-users-h...@xmlgraphics.apache.org
