pdf_generator.rb

require 'fileutils'
require 'logger'
require 'erb'

# Pdf generation service based on wkhtmltopdf.

class PdfGenerator
  class WkhtmltopdfError < RuntimeError; end

  DPI = 96 # Pixels in inch
  DPC = (DPI / 2.54) # = 37.795 Pixels in centimeter

  # See http://madalgo.au.dk/~jakobt/wkhtmltoxdoc/wkhtmltopdf-0.9.9-doc.html
  #
  # Options without argument just take true, rest should have string as value.
  # To disable option set it to false.
  PDF_OPTIONS = {
    'quiet'         => true,

    # Header is disabled.
    # 'header-html' => 'header.html',
    # 'footer-html' => 'footer.html',

    'print-media-type' => true,
    # 'disable-smart-shrinking' => true,

    'page-size'     => 'A4',
    'margin-top'    => '0.5cm',
    'margin-right'  => '0.5cm',
    'margin-bottom' => '1cm',
    'margin-left'   => '0.5cm',
    'encoding'      => "UTF-8",
  }

  PDF_DIR = 'pdfs'
  FileUtils.mkdir_p(PDF_DIR)

  attr_accessor :error_message
  attr_accessor :note

  def logger
    defined?(Rails) ? Rails.logger : (@logger ||= Logger.new($stdout))
  end

  def pdf_options
    PDF_OPTIONS
  end

  def note_url
    'index.html'
  end

  def pdf_path
    File.join(PDF_DIR, "ramki.pdf")
  end

  def wkhtmltopdf
    @wkhtmltopdf ||= begin
      pdf_command = [
        `ls -1 bin/wkhtmltopdf* 2>/dev/null`.split("\n").last,
        `which wkhtmltopdf`
      ].detect{|c| !c.nil? }

      raise("Cannot locate wkhtmltopdf in #{Dir.pwd} or $PATH") if pdf_command.nil?

      pdf_command.strip
    end
  end

  def xvfb_wrapper
    "" #'xvfb-run -s "-screen 0, 1600x1200x24"'
  end

  # wkhtmltopdf [OPTIONS]... <input file> [More input files] <output file>
  def pdf_command
    normalized_options = pdf_options.map{|k, v|
      v ? "--#{k} #{v == true ? "" : v}" : nil
    }.compact.join(" ")

    "#{xvfb_wrapper} #{wkhtmltopdf} #{normalized_options} #{note_url} #{pdf_path}"
  end

  def render
    File.open('index.html', 'w') do |f|
      f.write ERB.new(File.read('index.html.erb')).result
    end
  end

  # Generates a pdf.
  def generate
    render
    perform
  end

  # Performs a pdf generation.
  def perform
    logger.debug "Running: " + pdf_command

    # See http://mentalized.net/journal/2010/03/08/5_ways_to_run_commands_from_ruby/
    redirection = " 2>&1"
    @out = IO.popen(pdf_command + redirection, "wb+") do |pdf|
      pdf.close_write
      pdf.gets(nil)
    end
    
    unless $? == 0
      self.error_message = "Failed to generate pdf via: #{wkhtmltopdf}. Exit code: #{$?}."
      raise(WkhtmltopdfError, error_message, caller[1..-1])
    end
  end
end

if __FILE__ == $0
  PdfGenerator.new.generate
end

print.css

/*
 * Printing styles based on HTML5 Boilerplate
 *
 * What follows is the result of much research on cross-browser styling.
 * Credit left inline and big thanks to Nicolas Gallagher, Jonathan Neal,
 * Kroc Camen, and the H5BP dev community and team.
 *
 * Additional modifications and printing classes by Marcin Raczkowski
 */

/* ==========================================================================
   Base styles: opinionated defaults + Print styles.
   Inlined to avoid required HTTP connection: h5bp.com/r
   ========================================================================== */

html,
body,
button,
input,
select,
textarea {
    color: #000;/* Black prints faster: h5bp.com/s */
    background-color: #fff;
}

html, body {
    font-size: 9pt;
    line-height: 1.4;
    font-family: Georgia, serif;
}

@media screen {
    html, body {
        font-size: 10px;
    }
}

body {
    /* Print related */
    box-shadow: none !important;
    text-shadow: none !important;
}

a,
a:visited {
    text-decoration: underline;
}

a[href]:after {
    content: " (" attr(href) ")";
}

abbr[title]:after {
    content: " (" attr(title) ")";
}

/*
 * Don't show links for images, or javascript/internal links
 */

.ir a:after,
a[href^="javascript:"]:after,
a[href^="#"]:after {
    content: "";
}

pre,
blockquote {
    border: 1px solid #999;
    page-break-inside: avoid;
}

thead {
    display: table-header-group; /* h5bp.com/t */
}

tr,
img {
    page-break-inside: avoid;
}

img {
    max-width: 100% !important;
}

p,
h2,
h3 {
    orphans: 3;
    widows: 3;
}

h2,
h3 {
    page-break-after: avoid;
}



/*
 * A better looking default horizontal rule
 */

hr {
    display: block;
    height: 1px;
    border: 0;
    border-top: 1px solid #ccc;
    margin: 1em 0;
    padding: 0;
}

/*
 * Remove the gap between images and the bottom of their containers: h5bp.com/i/440
 */

img {
    vertical-align: middle;
}

/*
 * Remove default fieldset styles.
 */

fieldset {
    border: 0;
    margin: 0;
    padding: 0;
}

/*
 * Allow only vertical resizing of textareas.
 */

textarea {
    resize: vertical;
}


/* ==========================================================================
   Additional print styles. Usefull for previews & document authoring.
   ========================================================================== */

body {
  margin: 0 auto;
  position: relative;
}

body.vertical {
  width: 21cm; /* A4 sized page with 0.5 cm margin/padding */
  padding: 0.5cm 0.5cm 1cm; /* USe these values if smart shrinking is disabled,they must mach margins */
}

body.horizontal {
  width: 29.7cm; /* A4(210x297) sized page with 0.5 cm margin top & 1cm margin bottom */
  padding: 0.5cm 0.5cm 1cm;
}

body.vertical .page {
    width: 20cm; /* A4 sized page with 0.5 cm margin */
    height: 28.1cm; /* 29.7 height - 0.5 top margin - 1cm bottom margin - 0.1 for rounding errors.  */
}

body.horizontal .page {
    width: 29.7cm; /* A4 sized page with 0.5 cm margin */
    height: 19.4cm; /* 21 (A4 H) - 0.5 (top margin) - 1 (bottom margin) - 0.1(rounding errors) */
}

/* gives us roughly 200x287 or 287x200 cm working area */
body .page {
  position: relative;
  margin: 0;
  page-break-inside: avoid;
}

@media screen {
  body .page {
    overflow: hidden;

    padding: 2px;
    outline: black 1px solid;
    outline-offset: 0.5cm;
    margin-top: 1cm;
    margin-bottom: 1.5cm;
  }
}

/* Compact definition list */

dl.compact {
  margin: 0;
  font-size: 0.9em;
  width: 5cm;
}

dl.compact dt {
  font-weight: bold;
  clear: left; float: left;

  width: 2.25cm;
  white-space: nowrap;
  overflow: hidden;
}
dl.compact dd {
  float: left;
  margin: 0 0 0 20px;
  white-space: nowrap;
  overflow: hidden;
}

/* Fixed width tables + some default table styles */

table.fixed {
  table-layout: fixed;
}

table.fixed td, 
table.fixed th {
  white-space: nowrap;
  overflow: visible;
  word-break: break-all;
}

table td,
table th {
  padding: 0.3em 0.6em;
  border: 1px solid black;
  white-space: nowrap;
}

table th {
  padding: 0.3em 0;
  text-align: center;
}

table.zebra { 
  width: 100%;
  border: 2px solid black;
}

table.zebra th { background-color: #aaa !important; }
table.zebra td { background-color: #fff !important; }
table.zebra td:nth-child(2n) { background-color: #ccc !important; }

/* ==========================================================================
   Helper classes
   ========================================================================== */

.hidden {
    display: none !important;
    visibility: hidden;
}

/*
 * Hide visually and from screenreaders, but maintain layout
 */

.invisible {
    visibility: hidden;
}

/*
 * Clearfix: contain floats
 *
 * For modern browsers
 * 1. The space content is one way to avoid an Opera bug when the
 *    `contenteditable` attribute is included anywhere else in the document.
 *    Otherwise it causes space to appear at the top and bottom of elements
 *    that receive the `clearfix` class.
 * 2. The use of `table` rather than `block` is only necessary if using
 *    `:before` to contain the top-margins of child elements.
 */

.clearfix:before,
.clearfix:after {
    content: " "; /* 1 */
    display: table; /* 2 */
}

.clearfix:after {
    clear: both;
}

/*
 * For IE 6/7 only
 * Include this rule to trigger hasLayout and contain floats.
 */

.clearfix {
    *zoom: 1;
}

.ruler {
  border-left: 1px solid black;
  border-bottom: 1px solid black;
  border-right: 1px solid black;
}