pdflatex.rb

require 'erb'
require 'tempfile'

class Pdflatex

  TEMPLATE_DIR = File.join(RAILS_ROOT, 'app', 'views', 'tex')

  def self.run(template_path, locals = nil)
    template = File.new(template_path).read
    erb = ERB.new(template)
    tex = Tempfile.new('pdflatex', WORK_DIR)
    tex.puts erb.result(binding)
    tex.flush
    cmd = "pdflatex -interaction batchmode " +
          " -output-directory #{File.dirname(tex.path)} #{tex.path}"
    res = `#{cmd}`
    unless (0 == $?.to_i)
      raise "could not transform using #{cmd}: #{res}"
    end
    tex.path + '.pdf'
  end

end