Wednesday, April 25, 2012

Axlsx 1.1.3 - Release Announcement: Conditional Formatting Excel with Ruby and Ruby on Rails

Contributors Rock

 This will be the first in a series of "Contributors Rock" posts where I hope I will be able to express my gratitude for those that have stepped up and added functionality as well as used the gem.

@scpike of #mom (hashtagmom)  and other things I am not allowed to talk about is one of those people.

A couple of months ago, after releasing the first version of axlsx, I started thinking about what else was really needed on the sharp edge. One of the things that came up was conditional formatting, so I tossed an issue into the repo: Implement Conditional Formatting for worksheet figuring I'd get around to it sometime in June. What came later was totally unexpected. @scpike piped in saying that he was interested in the feature and posted: "I started working on it in my fork (progress so far), but I have a couple of questions. "

I was mind blown. The code was clean, thoroughly documented, well tested and in line with the style of the rest of the gem. Hats off mate - I would have done a worse job of it myself.

 

The Business End

 So what is conditional formatting? In essence, it allows you to change the style for your cells based on the content of the worksheet. Show your rising profitability in smashing green, or your spiking operations costs in a jarring red. Let have a look at a simple example:

Hitting the high notes

The code for this example is available here
require 'axlsx' 
p = Axlsx::Package.new
p.workbook do |wb|
  # define your regular styles
  styles = wb.styles
  title = styles.add_style(:sz => 15, :b => true, :u => true)
  default = styles.add_style(:border => Axlsx::STYLE_THIN_BORDER)
  header = styles.add_style(:bg_color => '00', :fg_color => 'FF', :b => true)
  money = styles.add_style(:format_code => '#,###,##0'
                           :border => Axlsx::STYLE_THIN_BORDER)
  percent = styles.add_style(:num_fmt => Axlsx::NUM_FMT_PERCENT 
                             :border => Axlsx::STYLE_THIN_BORDER)


  # define the style for conditional formatting - its the :dxf bit that counts!
  profitable =  styles.add_style(:fg_color=> 'FF428751',  
                                 :sz => 12, :type => :dxf, :b => true)


  wb.add_worksheet('the high notes') do  |ws|
    ws.add_row ['A$$le Q1 Revenue Historical Analysis (USD)'], 
                :style => title
    ws.add_row
    ws.add_row ['Quarter', 'Profit', '% of Total'], :style => header
    ws.add_row ['Q1-2010', '15680000000', '=B4/SUM(B4:B7)'],  
                :style => [default, money, percent]
    ws.add_row ['Q1-2011', '26740000000', '=B5/SUM(B4:B7)'],  
                :style => [default, money, percent]
    ws.add_row ['Q1-2012', '46330000000', '=B6/SUM(B4:B7)'],  
                :style => [default, money, percent]
    ws.add_row ['Q1-2013(est)', '72000000000', '=B7/SUM(B4:B7)'],  
                :style => [default, money, percent]


    ws.merge_cells 'A1:C1'

    # Apply conditional formatting to range B4:B7 in the worksheet
    ws.add_conditional_formatting('B4:B7', { :type => :cellIs,
                                    :operator => :greaterThan,
                                    :formula => '27000000',
                                    :dxfId => profitable,
                                    :priority => 1 })
  end
end
p.serialize 'the_high_notes.xlsx'