Martin on Rails

Unfortunatly there seems to be a bug with justification in the PDF::Writer library, which I described in detail in a bug report on the PDF::Writer site. On the mailing list this was confirmed as a known bug.

Because I needed a solution I decided to have a look at the Ruby port of the well known PHP library FPDF, which is called Ruby FPDF by Olivier Plathey.

Justification works fine there, but there is no solution built in the base FPDF library to have justification with formatted text (some words in a flowing text which are bold, italic, have other font sizes, etc.). But there is a nice “flowing block” module by Damon Kohler for the PHP version of FPDF, which solves exactly this problem.

So I decided to to a Ruby port by my own, which is what I did and what I hope that you find useful as well. Here is an example how to use it:

require 'flowing_block'
 
pdf = PDF.new
 
pdf.AddPage()
pdf.newFlowingBlock( 40, 6, 0, 'L')
pdf.SetFont('Helvetica', 'B', 8)
pdf.WriteFlowingBlock('Bonjour Martin!')
pdf.finishFlowingBlock
 
pdf.newFlowingBlock( 40, 6, 0, 'J')
pdf.SetFont('Helvetica', 'B', 16)
pdf.WriteFlowingBlock('Hello ')
pdf.SetFont('Helvetica', 'I', 8)
pdf.WriteFlowingBlock('World! ')
pdf.SetFont('Times','',10)
pdf.WriteFlowingBlock('This is a test of the flowing block script.')
pdf.SetTextColor(255, 0, 0);  # red color.. ;-)
pdf.SetFont('Helvetica', 'B', 12)
pdf.WriteFlowingBlock('Rot! ')
pdf.SetTextColor(0, 255, 0);  # green color.. ;-)
pdf.SetFont('Helvetica','',10)
pdf.WriteFlowingBlock(' of this should be justified correclty. It is sooooo amazing!! It is sooooo amazing!! It is sooooo amazing!! ')
pdf.finishFlowingBlock
 
pdf.Output('test.pdf')

I have put the Ruby FPDF library and the flowing block extension in ZIP-File which can be downloaded here.

Please have in mind that I am a Ruby beginner and that it’s very likely that there are lots of bugs in it. It’s also a matter of fact that the port is pretty ugly, mainly because I did not know a Ruby equivalent for the PHP pointer like =& operator. (If somebody knows how one can do that in Ruby, please post a comment!).

So if you find a bug or a solution how to improve the code please do so – I will gladly post the update here!

Tags: Justification, PDF, Ruby

This entry was posted on Thursday, April 3rd, 2008 at 5:19 pm and is filed under Ruby Libraries. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.