Dashboard Images Revealed

Some interesting dashboard image facts:

You can embed images in your dashboards. OK, that's not news. Things you may not realize:

• You can embed images in your dashboards. OK, that's not news.
• You can specify a PDF as the image file, but Tableau won't produce an image.
  (you can embed the PDF in a Web Page component)
• Once you've inserted the image Tableau doesn't show you the image's source, so there's now way to tell what file is being shown.
• Tableau doesn't forget the images you've put in the Image component—if you add a second image, Tableau remembers the name of the first; add a third, the second is remembered, etc.
  So be careful about using placeholder images, their ghosts will be lurking about.

Revealing your Dashboards' Images

The Ruby script below will scan the current and all descendant directories for TWBs and for each one found will identify the images and report on them with the Workbook, Dashboard, and Image details. The information is captured as data in the CSV file "TCC_DI.csv", which you can analyze with Tableau.

---

# TCC_DI.rb - this Ruby script Copyright 2012, Christopher Gerrard
#           - show the images in the Workbooks' Dashboards


require 'nokogiri'
require 'open-uri'

$twbCnt, $twbNum, $recNum = 0, 0, 0

def init
    $f = File.open("TCC_DI.csv",'w')
    $f.puts 'Record #,Workbook,Workbook Dir,Dashboard,Image,Image Dir' unless $f.nil?
    print "\n\tScanning for Dashboard images\n\t"
end

def showImages twb
  doc = Nokogiri::XML(open(twb))
  $twbCnt += 1
  dashes = doc.xpath('//workbook/dashboards/dashboard' )
  if dashes.length > 0 then
    $twbNum += 1
    twbName = File.basename(twb)
    twbDir  = File.dirname(twb)
  end
  dashes.each do |d|
    dName  = d.xpath('./@name').text
    images = d.xpath('//zone[@type="bitmap"]')
    images.each do |i|
      iName = i.xpath('./@param').text
      print '.'
      imgName = File.basename(iName)
      imgDir  = File.dirname(iName)
      $f.puts "\"#{$recNum+=1}\",\"#{twbName}\",\"#{twbDir}\",\"#{dName.gsub('"','""')}\",\"#{imgName}\",\"#{imgDir}\""
      if $recNum.modulo(72) == 0 then print "\n\t" end
    end
  end
end

init

Dir.glob("**/*.twb") {|twb| showImages twb }

$f.close unless $f.nil?

plural = if $twbNum == 1 then '' else 's' end
puts "\n\tDone.\n\tFound #{$recNum} images in #{$twbNum} Workbook#{plural} of #{$twbCnt} Workbooks scanned"
if $recNum > 0 then
  puts "\tTCC_DI.csv contains the image names & the Dashboards containing them."
end

---

 

No Workbooks are harmed during the revealing of the Images.

Your workbooks are unaffected, nothing is done to them.

How to use TCC_DI.rb

• Prerequisites
• Minimal technical skills.
• Have Ruby installed and ready to run.
• Have the Nokogiri Ruby gem installed—it's used in the XML parsing.
• Have TCC_DI.rb in place—it doesn't matter where, or what name you use, as long as you know where it is.
  You can copy the code above and paste it into your favourite text editor.
• Running TCC_DI.rb
• Open a command prompt.
  (you can run it otherwise, but this is simple and straightforward)
• CD to the directory containing the Workbooks you're interested in.
• Run it: "[path to]\ruby    [path to]\TCC_DI.rb"
• Note, TCC_DI.rb also looks through all the directories below the current one.
• Presto. You now have a TCC_DI.csv file containing the information about your Dashboard images, if any.

The usual caveats.

TCC_DI.rb works fine with the limited testing it's been through, but it's definitely not bulletproof and hardened. It's only been run against Tableau v7 Workbooks, and it's entirely possible that images in other Tableau version Workbooks, or images coded in the TWBs in a manner other than the one in my sample TWBs not found might not be detected.

I hope it works for you, but make no guarantees. If you do use it and make improvements I hope that you'll post them back here as comments so I can learn from them, and hopefully other people can benefit from them too.