How to Generate PDF in Ruby on Rails(HowtoGeneratePDFs) ZT

时间：2023-02-05 22:50:59
This howto covers seven approaches to generating a PDF document with Rails.
  • HTMLDOC
  • PdfWriter
  • PDF::Writer (Austin Ziegler)
  • Ruby FPDF
  • JasperReports
  • PDF Form Fill
  • PDFlib and PDFlib-Lite
  • Rfpdf

Using HTMLDOC

The sample code below requires HTMLDOC.

  #in controller
  def pdf
    @article = Article.find(@params["id"])
    add_variables_to_assigns

    generator = IO.popen("htmldoc -t pdf --path \".;http://#{@request.env["HTTP_HOST"]}\" --webpage -", "w+")
    generator.puts @template.render("article/pdf")
    generator.close_write

    send_data(generator.read, :filename => "#{@article.title}.pdf", :type => "application/pdf")
  end

If you’re using Windows, you may have problems unless you add the following after generator = IO.popen…. 

generator.binmode

PdfWriter

Alternatively if you want more control over where everything is written/drawn onto the page James Hollingshead has put some code up at http://www.hollo.org/pdfwriter . It also generates everything in a single pass so no need for temporary files. It is very lightweight and all in a single file that can be copied to the lib directory and required. Using it is as simple as:

  #in controller
  def pdf
    send_data gen_pdf, :filename => "something.pdf", :type => "application/pdf" 
  end

 private
  def gen_pdf
      pdf = PdfWriter.new
      pdf.newPage
          pdf.writeText(10, 200, 'Text to write', :fontsize => 18)
          pdf.writeLine(0, 0, 100, 100) #Draw line
      pdf.newPage
          pdf.writeText(10, 210, 'Now on page 2')
      pdf.writeEnd
  end

PDF::Writer (Austin Ziegler)

http://rubyforge.org/projects/ruby-pdf/

(Instructions updated by Austin Ziegler.)

Install PDF::Writer (and dependencies) with \RubyGems:

gem install pdf-writer

One way is to create a .pdf file in public/pdf and send it to the browser with a redirect, as shown below:

  #in controller
  require 'pdf/writer'

  def pdf
    gen_pdf
    redirect_to("#{@request.relative_url_root}/pdf/hello.pdf")
  end

  private
  def gen_pdf
    pdf = PDF::Writer.new
    pdf.select_font "Times-Roman" 
    pdf.text "Hello, Ruby.", :font_size => 72, :justification => :center

    pdf.save_as("public/pdf/hello.pdf")
  end

Alternately, generate the document and send it directly to the browser:

 # in controller
 require 'pdf/writer'

 def pdf
   _p = PDF::Writer.new
   _p.select_font 'Times-Roman'
   _p.text "Hello, Ruby.", :font_size => 72, :justification => :center
   send_data _p.render, :filename => filename, :type => "application/pdf" 
 end

This is the preferred way to send documents, as the documents will be sent inline and two requests won’t step on each others’ generated documents. There will be further details on what is possible in an upcoming Ruby Code & Style article that I’m writing.

Another alternative method is to create a template handler to handle, say, rpdf files with :


ActionView::Base.register_template_handler 'rpdf', ActionView::PDFRender

in your config/environment.rb file, and put the following somewhere in the lib directory :


module ActionView # :nodoc:
  class PDFRender
    PAPER = 'A4'
    include ApplicationHelper

    def initialize(action_view)

      @action_view = action_view
    end

    # Render the PDF
    def render(template, local_assigns = {})
      @action_view.controller.headers["Content-Type"] ||= 'application/pdf'

      # Retrieve controller variables
      @action_view.controller.instance_variables.each do |v|
        instance_variable_set(v, @action_view.controller.instance_variable_get(v))
      end

      pdf = ::PDF::Writer.new( :paper => PAPER )
      pdf.compressed = true if RAILS_ENV != 'development'
      eval template, nil, "#{@action_view.base_path}/#{@action_view.first_render}.#{@action_view.pick_template_extension(@action_view.first_render)}" 

      pdf.render
    end
  end
end

And in your app/views/foo/bar.rpdf file you put


pdf.select_font "Times-Roman" 
pdf.text "Hello, Ruby.", :font_size => 72, :justification => :center

If you want to use ActionView helpers via this method, just use the @action_view instance variable:


pdf.text "Price is:" 
pdf.text @action_view.number_to_currency(500)

Check you’re not using a layout for actions rendering an rpdf template

Note: if you’re on a Mac and you get ‘JPEG marker not found’ or ‘undefined method `unpack’ for nil:\NilClass (\NoMethodError)’ errors with the above, this seems to be a problem with Apple’s version of Ruby on Tiger. See this thread: http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/145411

Installing Ruby with \DarwinPorts is one possible solution.

If you would like to have the user prompted to download the file instead of displaying it within the window (can be useful for handling validation prior to download), then add the following to your PDFRender class:


@action_view.controller.headers["Content-Disposition"] ||= 'attachment'

Ruby FPDF

An other alternative is Ruby FPDF, a port of PHP FPDF. It’s just one small Ruby file, which can be dropped in your Rails application “lib” folder. Download at http://brian.imxcc.com/fpdf/ (moved to http://zeropluszero.com/software/fpdf/ ?). Many examples, plus a font generator, are included.

  #in controller
  def pdf
    send_data gen_pdf, :filename => "something.pdf", :type => "application/pdf" 
  end

 private
  def gen_pdf
    pdf=FPDF.new
    pdf.AddPage
    pdf.SetFont('Arial','B',16)
    pdf.Cell(40,10,'Hello World!')
    pdf.Output 
  end

Here is an example of using content stored in a database and generating a PDF with FPDF.
Here is a problem that occurs, when trying to include JPGs or PNGs into the PDF on Mac OS: ErrorUsingFPDFWithJPGOrPNGOnMacOS

Fpdf::Table allows easy adding tables to Ruby FPDF.

JasperReports

JasperReports is a powerful—and even more important—well known open source Java reporting tool that has the ability to deliver rich content in formats such as PDF, RTF, HTML, CSV and XML. Read HowtoIntegrateJasperReports into Rails.

Notes

Headers for Internet Explorer

Note that you may have to play around a bit to get send_data to work with Internet Explorer. The following lines worked wonders for me (see the API docs for more info on send_data):


  if @request.env['HTTP_USER_AGENT'] =~ /msie/i
    @headers['Pragma'] = ''
    @headers['Cache-Control'] = ''
  else
    @headers['Pragma'] = 'no-cache'
    @headers['Cache-Control'] = 'no-cache, must-revalidate'
  end

Do not use a layout

If you are not using send_data, make sure you disable layout for your pdf method. Note: This can also be accomplished by render_without_layout

class YourController < ApplicationController
  layout "layouts/yourLayout" ,  :except => :yourPdfMethod

  def yourPdfMethod
     ..
  end
end

PDF Form Fill

Using all the tools listed above to create a nice looking pdf file will take you a lot of time to learn how to do. The easier way is to create a form using Adobe Acrobat. Simply use the text field tool to create where dynamic text should be entered in at and give them variable names. Now use this script to create an FDF compatible file…

def createFDF(info)
    data = "%FDF-1.2\x0d%\xe2\xe3\xcf\xd3\x0d\x0a"; # header
    data += "1 0 obj\x0d<< " # open the Root dictionary
    data += "\x0d/FDF << " # open the FDF dictionary
    data += "/Fields [ " # open the form Fields array

      info.each { |key,value|
          if value.class == Hash
              value.each { |sub_key,sub_value|
                  data += '<< /T (' + key + '_' + sub_key + ') /V '
                  data += '(' + sub_value.to_s.strip + ') /ClrF 2 /ClrFf 1 >> '
              }
          else
              data += '<< /T (' + key + ') /V (' + value.to_s.strip + ') /ClrF 2 /ClrFf 1 >> '
          end
      }

    data += "] \x0d" # close the Fields array
    data += ">> \x0d" # close the FDF dictionary
    data += ">> \x0dendobj\x0d" # close the Root dictionary

    # trailer note the "1 0 R" reference to "1 0 obj" above
    data += "trailer\x0d<<\x0d/Root 1 0 R \x0d\x0d>>\x0d" 
    data += "%%EOF\x0d\x0a" 
    afile = File.new("/tmp/rails_" + rand.to_s, "w") << data
    afile.close
    return afile
  end

This function will return your fdf temp file, Now to enter that info into a pdf you will need pdftk found at http://www.accesspdf.com/pdftk/

Once that is installed you can do something like this…

u = User.find(:first)

fdf = createFDF(u.attributes)

pdf_output = `pdftk ./user_info.pdf fill_form #{fdf.path} output - flatten`
File.delete(fdf.path)

Next just pass the pdf_output to the browser for the user to get the pdf file, or save it in the database.

Happy hacking! – Chief

PDFlib and PDFlib-Lite

PDFlib newest release contains Ruby bindings. PDFlib and PDFlib-Lite is one of the fastest PDF generation libraries in production. This is a commercial library though (unless you meet their strict requirements for their opensource license).

For installation and usage information, you can view this 2 part series by Bob Silva

Generating PDFs in Rails – Part I – Installing
Generating PDFs in Rails – Part II - Real World Usage

Comments:
Disclaimer: Personal Opinion. One of the things that is holding Rails away from the enterprise is its reporting solutions (or lack of). There’s no tool in the neatness of JasperReports (yet). – Tamer Salama

Comments:
Regarding PDF FORM FILL - Where would you put the script to create the FDF file? In the controller?

Rfpdf Plugin

I am a long time user of PDFlib. When I started working with Ruby on Rails, like Ruby on Rails I searched for a free PDF capable solution. I tried RTex with mixed results – sometimes it worked sometimes it didn’t. Then I found Ruby on FPDF. I have been very pleased.

I did like the template view capability of RTex, which accommodated embedding the ruby code in files with .rtex extensions.

I also had a client that needed Chinese, Japanese and Korean support. These languages were supported in the PHP version of FPDF but only Chinese had been ported and that port didn’t work properly so I spent the weekend porting these three languages to Ruby from PHP.

The Rfpdf Plugin incorporates: Ruby FPDF, e-ruby template view support (.rfpdf files) and additional Asian support for Chinese, Japanese and Korean languages.

Download it at http://rubyforge.org/projects/rfpdf/ or see
the other install/example details at Rfpdf Plugin.

From: http://wiki.rubyonrails.com/rails/pages/HowtoGeneratePDFs

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