title: (J)Ruby in Action: Generating PDF Documents from HTML Templates

(J)Ruby in Action: Generating PDF Documents from HTML Templates

Agenda

HTML Print Pilot Demo
HTML Templates w/ Embedded Ruby (Conditions, Loops, Methods)
Ruby in Action
- Reading XML Documents Using xml_simple Library
- OpenStructs
- Open Class Concept
- method_missing
- Using Embedded Ruby Templates (ERB)
Ruby in a Java World - jruby-complete.jar
HTML to PDF Conversion
- wkhtmltopdf and Alternatives
- HTML5 Goodies for Print
- CSS3 Paged Media and Alternatives
The End

Dynlang/Scripting Profile Questions – Ice Breakers

Are you using any Scripting Languages for Java?
What? Python? Groovy? Ruby?
Why? / What for? -> Production? Testing? Configuration? Templates? Other?

Bonus: Have you developed a web application in a scripting language on a Java infrastructure/stack? (e.g. JRuby on Rails, Google App Engine w/ Groovy, etc.)

Sample:

Yes / Many
Ruby, Groovy
Production, Templates, Testing

No / Zero
10000 % Java!! Java Rules!! Java Java

HTML Print Pilot

Idea: Make design of documents as easy as possible

Use HTML for document templates (use CSS for styling and positioning)
Use a scripting language for conditions, placeholders, loops, etc. (-> Ruby)

HTML Print Pilot in Action

Command Line:

$ jruby print.rb samples/BUFT/BUFT_Angebot_Master.html samples/BUFT/BUFT1.xml > o/BUFT1.html
$ jruby print.rb samples/BUFT/BUFT_Angebot_Master.html samples/BUFT/BUFT2.xml > o/BUFT2.html

Result:

HTML to PDF Conversion

$ wkhtmltopdf --use-print-stylesheet o/BUFT1.html o/BUFT1.pdf

Result:

HTML Templates Using Embedded Ruby (`erb`) - 1st Impression

Example: QP_Antrag.html

<ul class="bindestrich">Mein mobiles ServicePaket:</p>
  <li><b>Portal mySanssouci:</b> Jederzeit online Zugriff auf alle Informationen rund
  um meine QualitätsPartnerschaft</li>
  <li><b>Sanssouci Unwetterwarnung:</b> Örtlich und zeitlich exakte Vorhersagen per SMS
  und/oder E-Mail</li>
</ul>

<p>Ich beantrage die QualitätsPartnerschaft und bitte um Verrechnung meiner
Versicherungsverträge, bei denen ich alleiniger Prämienzahler und Verbraucher im Sinne
des Konsumentenschutzgesetzes (KSchG) bin, über das PartnerConto und nehme zustimmend
zur Kenntnis, dass bei Umstellung auf die QualitätsPartnerschaft die Serviceleistungen
aus einem eventuell vorhandenen StarConto, mit Ausnahme der Verrechnungsfunktion für
Verträge von Kooperationsunternehmen, durch die Serviceleistungen der
QualitätsPartnerschaft ersetzt werden.
</p>

<p>Ich beauftrage
  <% if benutzer.geschlecht == 1 %>
    Herrn
  <% end %>
  <% if benutzer.geschlecht == 2 %>
    Frau
  <% end %>
<%= benutzer.titel %> <%= benutzer.vorName %> <%= benutzer.zuName %>
mich als persönlicher Betreuer in sämtlichen Versicherungsangelegenheiten meiner Verträge
des ExklusivVertriebs zu beraten, zu betreuen und zu unterstützen. Ich ermächtige sie/ihn
hiermit gleichzeitig, alle dafür relevanten Vertrags- und Schadendaten in meinem Namen
zu erheben bzw. in diese Einsicht zu nehmen.</p>

Why Ruby? Why Not Groovy?

Ruby Pros:

Write Ruby Once, Runs Anywhere! .Net Runtime – Yes, Java Runtime – Yes, C-Runtime – Yes
Easier To Use and Learn for Non-Java Programmers (e.g. Casual Developers such as Designers/Analysts)
Better Documentation (More Books, etc.)
More Innovations (Different Culture – Enterprise-y? Ethos -Programmer Happiness, Simple, etc.)
Works Great as Template Language e.g. for Web Views (No {}, method () optional, etc.)
Better Meta-Progamming
Much More!

Groovy Pros:

Better Java Integration
Easier To Use and Learn for Java Programmers

HTML Templates – Conditions, Loops

Conditions (if):

<% if o.sparten.registrierungUnwetter.vorhanden? %>
  <td style="text-align: right">ja</td>
<% else %>
  <td style="text-align: right">nein</td>
<% end %>

Loops (each):

<% o.vertraegeUntergeordnet.each do |qpsub| %>
  <tr>
    <td><%= qpsub.vereinbarungQP.status %></td>
    <td><%= qpsub.vereinbarungQP.polizzenNr %></td>
    <td><%= qpsub.vereinbarungQP.antragsID %></td>
    <td><%= qpsub.vereinbarungQP.prodkurzname %></td>
    <td><%= qpsub.vereinbarungQP.praemieAlt %></td>
    <td><%= qpsub.vereinbarungQP.praemieNeu %></td>
    <td><%= qpsub.vereinbarungQP.praemieDiff %></td>
  </tr>
<% end %>

HTML Templates – Macros, Functions

Definition:

<%
def vertragVorhanden?
  o.vertraegeUntergeordnet.each do |v|
    vQP = v.vereinbarungQP
    if vQP.markierungCode == 1 || vQP.markierungCode == 2
      return true
    end
  end
  false
end
%>

Usage:

<% if vertragVorhanden? %>
  <b>Verträge/Anträge, die nur über das PartnerConto verrechnet werden und nicht zur
  Bereichswertung zählen</b><br />
  (alle Prämien in EUR, inkl. Steuern, exkl. motorbezogener Versicherungssteuer)
<% end %>

Easy XML Data Access Using Dot-Notation

Access XML Data using Dot-Notation (C-Struct-Like):

o.besondereHinweise
o.sparten.registrierungUnwetter.registrierungMobil.firma

Define Short-Cuts:

sparten = o.vereinbarung.sparten
vn = sparten.versichertePersonBuft.vereinbarungZuPartner.find{ |v| v.zuordnungsTyp == 1801 }.partner
pz = vn

Using Short-Cuts:

vn.hauptWohnsitz.strasse
pz.bankverbindungen.bankKontoNr

Arrays:

vn.kuvPartnerInnen[0].vertriebsKuv.kundenverbindung.vtbSchiene

Ruby in Action - Reading XML Documents Using `xml_simple` Library

XML Source:

<SystemMandant value="" type="java.lang.Object" desc="null">
  <vereinbarung value="" type="java.lang.Object" desc="null">
    <systemKlasse value="" type="java.lang.Object" desc="null">
      <vpmsModellVersNr value="20100312" type="java.lang.Object" desc="null">
      </vpmsModellVersNr>
    </systemKlasse>
    <vereinbarungTyp value="163" type="java.lang.Object" desc="null">
    </vereinbarungTyp>
    <sparten value="" type="java.lang.Object" desc="null">
      <versichertePersonBuft value="" type="java.lang.Object" desc="null">
        <vereinbarungZuPartner value="" type="java.lang.Object" desc="null">
  <partner value="" type="java.lang.Object" desc="null">
    <geburtsDatum value="12.11.1970" type="java.lang.Object" desc="null">
    </geburtsDatum>
    <geschlecht value="2" type="java.lang.Object" desc="null">
      <choice>
        <item key="0" value="Organisation"/>
        <item key="1" value="männlich"/>
        <item key="2" value="weiblich"/>
      </choice>
    </geschlecht>
    <berufsTitel value="" type="java.lang.Object" desc="null">
      <choice>
        <item key="44" value="Dipl.Arch. Dkfm."/>...
      </choice>
    </berufsTitel>
    <berufsTitelZwei value="" type="java.lang.Object" desc="null">
      ...
    </berufsTitelZwei>
    <hauptWohnsitz value="" type="java.lang.Object" desc="null">
      ...

Ruby Code – xml_simple Library in Action:

# step 1: read xml soruce into memory as string

  xml = File.read( 'samples/BUFT/BUFT1.xml' )

# step 2: parse xml using XmlSimple Lib (result stored in variable @o)

  @o = XmlSimple.xml_in( xml )

# step 3: pretty print (dump) internal structure

  pp @o

Internal Structure (JSON-like; just Values, Arrays and Hashes):

{"value"=>"",
  "type"=>"java.lang.Object",
  "desc"=>"null",
  "vereinbarung"=>
    {"value"=>"",
     "type"=>"java.lang.Object",
     "desc"=>"null",
     "systemKlasse"=>
      {"value"=>"",
       "type"=>"java.lang.Object",
       "desc"=>"null",
       "vpmsModellVersNr"=>
        {"value"=>"20100312",
         "type"=>"java.lang.Object",
         "desc"=>"null",
         "text"=>"\n\t\t\t"}},
     "vereinbarungTyp"=>
      {"value"=>"163",
       "type"=>"java.lang.Object",
       "desc"=>"null",
       "text"=>"\n\t\t"},
     "sparten"=>
      {"value"=>"",
       "type"=>"java.lang.Object",
       "desc"=>"null",
       "versichertePersonBuft"=>
        {"value"=>"",
         "type"=>"java.lang.Object",
         "desc"=>"null",
         "vereinbarungZuPartner"=>
          [{"index"=>"0",
            "value"=>"",
            "type"=>"java.lang.Object",
            "desc"=>"null",
            "partner"=>
             {"index"=>"0",
              "value"=>"",
              "type"=>"java.lang.Object",
              "desc"=>"null",
              "geburtsDatum"=>
               {"index"=>"0",
                "value"=>"12.11.1970",
                "type"=>"java.lang.Object",
                "desc"=>"null",
                "text"=>"\n\t\t\t\t\t\t"},
                "geschlecht"=>
                 {"index"=>"0",
                  "value"=>"2",
                  "type"=>"java.lang.Object",
                  "desc"=>"null",
                  "choice"=>
                   {"item"=>
                     [{"key"=>"0", "value"=>"Organisation"},
                      {"key"=>"1", "value"=>"m\303\244nnlich"},
                      {"key"=>"2", "value"=>"weiblich"}]}},
                "berufsTitel"=>
                 {"index"=>"0",
                  "value"=>"",
                  "type"=>"java.lang.Object",
                  "desc"=>"null",
                  "choice"=>
                   {"item"=>
                     [{"key"=>"44", "value"=>"Dipl.Arch. Dkfm."},

Allows Access Using Hash:

@o['vereinbarung']['systemKlasse']['vmpsModellVersNr']['value'] => 20100312
@o['vereinbarung']['sparten']['versichertePersonBuft']['vereinbarungZuPartner']['partner']['geburtsDatum'] => 12.11.1970

Ruby in Action – OpenStructs – Easy Dot Access

Convert Hash Access to Dot Access Using OpenStructs

Classic Access using Hash Access:

@o['vereinbarung']['systemKlasse']['vmpsModellVersNr']['value'] => 20100312
@o['vereinbarung']['sparten']['versichertePersonBuft']['vereinbarungZuPartner']['partner']['geburtsDatum'] => 12.11.1970

Easy Dot-Access using OpenStruct:

@o.vereinbarung.systemKlasse.vmpsModellVersNr.value => 20100312
@o.vereinbarung.sparten.versichertePersonBuft.vereinbarungZuPartner.partner.geburtsDatum => 12.11.1970

What is an OpenStruct?

Usage:

hash = { "key"=>"0", "value"=>"Organisation" }
item = OpenStruct.new(hash)
item.key => "0"
item.value => "Organisation"

Ruby in Action – Open Class Concept – Extend Existing Classes

Let's make the conversion recursive (that is, for complete parsed data tree):

class Object
  def to_openstruct
    self
  end
end

class Array
  def to_openstruct
    map{ |el| el.to_openstruct }
  end
end

class Hash
  def to_openstruct
    mapped = {}
    each{ |key,value| mapped[key.to_s] = value.to_openstruct }
    OpenStruct.new(mapped)
  end
end

That’s it. Usage:

@o = @o.to_openstruct

Ruby in Action - `method_missing` - Accessing Non-Existing Fields

Accessing Non-Existing Fields in OpenStruct:

class MyOpenStruct
  def initialize( hash )
    @hash = hash
  end
  ...
  def method_missing(mn,*a)
    mn = mn.to_s
    if @hash.has_key?(mn)
      @hash[mn]
    else
      STDERR.puts "*** warning: field '#{mn}' not found in hash; returning OpenStructNil"
      MyOpenStructNil.new( self, mn )
    end
  end

Accessing Non-Existing Fields in Non-Existing Hash:

class MyOpenStructNil
  def initialize( parent, field )
    @parent = parent
    @field = field
  end
  ...
  def method_missing(mn,*a)
    mn = mn.to_s
    STDERR.puts "*** warning: field '#{mn}' not found (parent is nil)"
    MyOpenStructNil.new( self, mn )
   end

Ruby in Action - Using Embedded Ruby Templates (ERB)

# step 1: read template source into memory as string
  
  rhtml = File.read( 'samples/BUFT/BUFT_Master.html' )

# step 2: make string into a template object

  template = ERB.new( rhtml )

# step 3: merge (fill in) template using variables from binding

  result = template.result( binding() )

# step 4: write out results in new file

  File.open( 'o/BUFT1.html', 'w') {|f| f.write( result ) }

Ruby in a Java World - `jruby-complete.jar`

Command Line:

$ jruby print.rb samples/BUFT/BUFT_Angebot_Master.html samples/BUFT/BUFT1.xml > o/BUFT1.html

Using jruby-complete.jar:

$ java -jar jruby-complete.jar print.rb samples/BUFT/BUFT_Angebot_Master.html samples/BUFT/BUFT1.xml > o/BUFT1.html

What is jruby-complete.jar?

All-in-one Java-Archive (jar) for JRuby (also includes Ruby standard libs plus some extras).
No installation needed; just add jruby-complete.jar to your classpath.

HTML to PDF Conversion - `wkhtmltopdf`

What is wkhtmltopdf?

Open Source C++ Code
Builds on Qt Library and WebKit (wk)
Adds some extras for page breaking, headers & footers, table of contents, etc.

More Info, Source

Example:

$ wkhtmltopdf --use-print-stylesheet o/BUFT1.html o/BUFT1.pdf

HTML to PDF Conversion – Options/Alternatives

HTML/CSS Parser using iText API - Flying Saucer - 100 % Java (Open Source) - More Info, Article

HTML to FO (using XSLT-Templates)

HTML plus CSS3 (plus Paged Media!) - PrinceXML (Commercial, $3000/license) - More Info

HTML5 Goodies for Print

CSS3:

@font-face
multi columns
table layout using CSS
backgrounds, gradients
much more

SVG:

Scalable Vector Graphics (SVG)

CSS3 Paged Media Module:

Not (yet) supported in any browser (planned for Google Chromium Milestone 6!)
Supported by commercial HTML to PDF converter (PrinceXML)

What is the CSS3 Page Media Module About?

Page Breaking
Page Layout (Headers, Footers, Size)
Page Counter
And More

Example:

@page {
  size: 210mm 297mm; /* A4 */
  margin: 27mm 16mm 27mm 16mm; /* top, right, bottom, left */
}
@page :left {
  @top-left {
    content: "HTML Print Pilot";
  }
  @bottom-left {
   content: counter(page);
  }
}
@page :right {
  @top-right {
   content: string(header);
  }
}

More Info, Article

CSS3 Paged Media Alternative - Use JavaScript

Use JavaScript for Breaking Document into Pages (Pagination)
Use JavaScript for Adding Headers & Footers to Pages and Replace Place Holders such as {page}/{pages}

In HTML Print Pilot less than 100 lines of JavaScript (using jQuery Library)

Page Breaking Plus Adding Headers & Footers:

var pages = 1; // page counter
var runHeight = 0; // in pixel
var pageHeight = 580; // in pixel

// find header and footer
var header = $('.kopf:first');
var footer = $('.fuss:first');

var buildAll    = $( "<div id='seiten'></div>" );
var buildPage   = buildNewPage( header, footer ).appendTo( buildAll );
var buildAntrag = buildPage.find( '.angebot:first' );

$( '.angebot' ).children().each( function() {
  var width = $(this).width();
  var height = $(this).height();

  debug( runHeight + ' - tag:' + this.tagName + '['+ width + ' x ' + height +']' );

  if( (runHeight+height) > pageHeight )
  {
    debug( '** adding page break' );
    runHeight = 0;
    pages += 1;
    buildAll.append( "<div class='break'></div>" );
    buildPage = buildNewPage( header, footer ).appendTo( buildAll );
    buildAngebot = buildPage.find( '.angebot:first' );
  }
  runHeight += height;
  buildAngebot.append( $(this).clone() );
});

Replace Variables/Place Holders in Headers & Footers:

var page = 1;
buildAll.find( '.seitea4' ).each( function() {
  debug( '** processing page ' + page + '/' + pages );
  var header = $(this).find( '.kopf:first' );
  var footer = $(this).find( '.fuss:first' );
  header.html( header.html().replace( '{{page}}', page ).replace( '{{pages}}', pages ) );
  footer.html( footer.html().replace( '{{page}}', page ).replace( '{{pages}}', pages ) );
  page += 1;
});

The End - Q&A – Thanks

Ruby Books

Ruby:

Programming Ruby 1.9: The Pragmatic Programmers’ Guide, by Dave Thomas, Chad Fowler, and Andy Hunt, 2009
The Ruby Programming Language by David Flanagan (O’Reilly), 2008
Ruby Cookbook (O’Reilly), by Lucas Carlson and Leonard Richardson 2006
Practical Ruby Gems by David Berube (Apress), 2007
Many Others

JRuby (Ruby Meets Java):

Using JRuby: Bringing Ruby to Java by Charles O Nutter, Thomas Enebo, Nick Sieger, Ola Bini, and Ian Dees, 2010
JRuby Cookbook (O’Reilly) by JRuby Cookbook by Justin Edelson and Henry Liu, 2008

Getting Started - Installing JRuby - 1-2-3 Steps

Download and unzip JRuby archive from jruby.org/download
Set JRUBY_HOME environment variable
Add %JRUBY_HOME%/bin to PATH

Hello Ruby

$ jruby -v

=> jruby 1.5.0 (ruby 1.8.7 patchlevel 249) (2010-05-12 6769999) (Java HotSpot(TM) Client VM 1.6.0_14) [x86-java]

$ jruby -S gem list

=> *** LOCAL GEMS ***
=>
=> columnize (0.3.1)
=> rake (0.8.7)
=> rspec (1.3.0)
=> ruby-debug (0.10.3)
=> ruby-debug-base (0.10.3.2)
=> sources (0.0.1)

$ jruby -e "puts 'Ruby Meets Java'"

=> Ruby Meets Java

hello.rb:

puts 'Ruby Meets Java'

$ jruby hello.rb

=> Ruby Meets Java

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

jruby_html_print.md

jruby_html_print.md

(J)Ruby in Action: Generating PDF Documents from HTML Templates

Agenda

Dynlang/Scripting Profile Questions – Ice Breakers

HTML Print Pilot

HTML Print Pilot in Action

HTML to PDF Conversion

HTML Templates Using Embedded Ruby (`erb`) - 1st Impression

Why Ruby? Why Not Groovy?

HTML Templates – Conditions, Loops

HTML Templates – Macros, Functions

Easy XML Data Access Using Dot-Notation

Access XML Data using Dot-Notation (C-Struct-Like):

Define Short-Cuts:

Using Short-Cuts:

Arrays:

Ruby in Action - Reading XML Documents Using `xml_simple` Library

Ruby in Action – OpenStructs – Easy Dot Access

Ruby in Action – Open Class Concept – Extend Existing Classes

Ruby in Action - `method_missing` - Accessing Non-Existing Fields

Ruby in Action - Using Embedded Ruby Templates (ERB)

Ruby in a Java World - `jruby-complete.jar`

HTML to PDF Conversion - `wkhtmltopdf`

HTML to PDF Conversion – Options/Alternatives

HTML5 Goodies for Print

CSS3 Paged Media Alternative - Use JavaScript

The End - Q&A – Thanks

Ruby Books

Getting Started - Installing JRuby - 1-2-3 Steps

Hello Ruby

Files

jruby_html_print.md

Latest commit

History

jruby_html_print.md

File metadata and controls

(J)Ruby in Action: Generating PDF Documents from HTML Templates

Agenda

Dynlang/Scripting Profile Questions – Ice Breakers

HTML Print Pilot

HTML Print Pilot in Action

HTML to PDF Conversion

HTML Templates Using Embedded Ruby (erb) - 1st Impression

Why Ruby? Why Not Groovy?

HTML Templates – Conditions, Loops

HTML Templates – Macros, Functions

Easy XML Data Access Using Dot-Notation

Access XML Data using Dot-Notation (C-Struct-Like):

Define Short-Cuts:

Using Short-Cuts:

Arrays:

Ruby in Action - Reading XML Documents Using xml_simple Library

Ruby in Action – OpenStructs – Easy Dot Access

Ruby in Action – Open Class Concept – Extend Existing Classes

Ruby in Action - method_missing - Accessing Non-Existing Fields

Ruby in Action - Using Embedded Ruby Templates (ERB)

Ruby in a Java World - jruby-complete.jar

HTML to PDF Conversion - wkhtmltopdf

HTML to PDF Conversion – Options/Alternatives

HTML5 Goodies for Print

CSS3 Paged Media Alternative - Use JavaScript

The End - Q&A – Thanks

Ruby Books

Getting Started - Installing JRuby - 1-2-3 Steps

Hello Ruby

HTML Templates Using Embedded Ruby (`erb`) - 1st Impression

Ruby in Action - Reading XML Documents Using `xml_simple` Library

Ruby in Action - `method_missing` - Accessing Non-Existing Fields

Ruby in a Java World - `jruby-complete.jar`

HTML to PDF Conversion - `wkhtmltopdf`