a few things remain

A few things left to do:

* Ability to add default options for each PDF, rather than having to pass it to each generate_* method call

* Doesn't check if the pdf already exists. By default, which should it do?
  - Overwrite the existing file. Let your users decide what they'd like to do here. 

* Consider the inclusion of css, or even generated css templates using pre existing libraries (lesscss or yerk – sass.)

Anything else?

notifier.rb

class Notifier < ActionMailer::Base
  def terms_of_service
    PdfGenerator.generate_terms_of_service('tos.pdf', :page_layout => :portrait) # or landscape
    # attach pdf to email
  end
end


Notifier.deliver_terms_of_service

pdf_generation.rb

class PdfGeneration

  def self.method_missing(method_symbol, *parameters, &block)
    if method_symbol.to_s =~ /^generate_(\w+)$/
      filename, options = *parameters
      raise "ERROR: PdfGeneration requires a filename string be set as the first parameter" unless filename && filename.is_a?(String)
      new_pdf = new((options || {}))
      new_pdf.send($1)
      new_pdf.save(filename)
    else
      super
    end
  end

  def initialize(options = {})
    @options = options
    @pdf = Prawn::Document.new(@options)
  end

  def method_missing(method_symbol, *parameters, &block)
    if @pdf.respond_to?(method_symbol)
      @pdf.send(method_symbol, *parameters, &block)
    else
      super
    end
  end

  def save(filename)
    @pdf.render_file(filename)
  end

end

pdf_generator.rb

# A PDF generation class that acts like action mailer in that you can call
# generate_* but drop generate_ on the method definition
class PdfGenerator < PdfGeneration
  def terms_of_service
    text "Terms Of Service"
    # any other prawn method can be called here and be called on the pdf object behind the scenes
  end
end