In my research, there are two main ways to generate a PDF:

 1. use an html -> pdf generator such as wkhtmltopdf or princexml (and 
 invoke the command line from ruby)

 2. use another library (Prawn seems to be the big one for ruby). You'll 
 have to learn the markup syntax for Prawn, but I think if you're willing 
 to get over that hurdle then you have more control than if you used an 
 html-> pdf generator.

 -Kristina

 On Wed, 14 Dec 2011 05:47:36 +0900, Dan Quach wrote:
> I want to generate a pdf calendar, and I have incoming calendar data
> from a json interface.  Any advice on things I should investigate to
> implement this?