Creating Reports in Silverlight (either as PDF or send it off to a printer)

Question

I have recently attempted to generate reports in Silverlight 4. In my problem domain, these reports either need to go directly to the printer and/or the client-side SL application creates a PDF and allows the user to store it somewhere.

As for the report, it's roughly composed of 50% flow text (incl. enumerations), 30% tables and 20% charts. The flow text part makes it slighty more challenging, as proper line breaking would have to take place.

So far, I have tried the following approaches - each with its own shortcomings that make them not so much feasible:

• Silverlight's own PrintDocument: technically, there are two major concerns. For one, getting page breaks to work and printing UIElements on it with proper layout is a bit of a dirty hackjob and full of compromises; thankfully that's the part I've managed to get working so far. However, the PrintDocument class always renders all visuals as bitmaps before sending them off; this is not so much fun, if one uses a PDF printer and hopes to still be able to search in / select text. David Poll's approach in "Silverlight and Beyond" [1] wasn't that helpful as well as it inherently follows the same approach and thus suffers from very similar issues.

• silverPDF [2]: a barely documented library that requires to do most of the layout manually (the former approach at least allowed me to re-use Silverlight's layouting engine). So far, I see no way to (for instance) measure paragraphs and the only sample with long flowtext uses hardcoded absolute values for layout rectangles. Also, the developing party seems to be inactive.

Personally, I'm now thinking of following an entirely different strategy: simply generate HTML documents. But I was hoping that the community here might have hints for the two approaches above or know other good approaches.

Thanks in advance, ~Manny

Answer 1

Do you need to generate the report on the client, or can you get the server to generate it? Your options are better if you can generate it on the server. Personally, I think the way Silverlight printing works at the moment is pretty poor for report usage (sending each page to the printer as raster rather than vector, resulting in potentially huge amounts of data travelling through the network, and lower printing quality output). I've found the best strategy is to generate the PDF on the server (enabling you to take advantage of a reporting engine), and display it in your application. There are also a few commercial products (such as Telerik's Silverlight Report Viewer, Report Sharp Shooter, or even First Floor Software's Document Toolkit). If a client side solution is really required, perhaps one of these might be the best option (although the printing quality will still be poor). Note that Silverlight 5 is supposed to have support for vector printing, but it's another 6 months or more away from release. Yet another option is Pete Brown and David Poll's open source reporting framework here: http://silverlightreporting.codeplex.com/.

If you want to take the option of generating the report on the server as a PDF and displaying it in your application, I've written an article on doing so here: http://www.silverlightshow.net/items/Building-a-Silverlight-Line-Of-Business-Application-Part-6.aspx. This doesn't work for OOB applications, but the source code accompanying my book (Pro Business Applications with Silverlight 4) does: apress.com/book/view/9781430272076.

Hope this helps...

Chris Anderson