The certificate layout

We will do some refactoring of the certificate layout. We will use a background and move place the text in the right place to make it look good.

Let's start with getting the image we'll use as the document background.

cd in to the pdf folder and download the certificate layout file from the workshop-assets repository. Again, we are going to use subversion:

svn export https://github.com/MakersSweden/workshop-assets/trunk/templates

Now we want to use the layout file as a background and make some changes to where we place the student and course information.

We need to make the following changes to the CertificateGenerator:

# lib/certificate_generator.rb

module CertificateGenerator

  def self.generate(certificate)
    details = {name: certificate.student.full_name,
               date: certificate.delivery.start_date.to_s,
               course_name: certificate.delivery.course.title,
               course_desc: certificate.delivery.course.description}
    output = "pdf/#{details[:name]}-#{details[:date]}.pdf"
    image = File.absolute_path('./pdf/templates/certificate_tpl.jpg')
    url = "http://my_domain.com/verify/#{certificate.identifier}"
    File.delete(output) if File.exist?(output)
    Prawn::Document.generate(output,
                             page_size: 'A4',
                             background: image,
                             background_scale: 0.8231,
                             page_layout: :landscape,
                             left_margin: 30,
                             right_margin: 40,
                             top_margin: 7,
                             bottom_margin: 0,
                             skip_encoding: true) do |pdf|
      pdf.move_down 245
      pdf.font 'assets/fonts/Gotham-Bold.ttf'
      pdf.text details[:name], size: 44, color: '009900', align: :center
      pdf.move_down 20
      pdf.font 'assets/fonts/Gotham-Medium.ttf'
      pdf.text details[:course_name], indent_paragraphs: 150, size: 20
      pdf.text details[:course_desc], indent_paragraphs: 150, size: 20
      pdf.move_down 95
      pdf.text " #{details[:date]}", indent_paragraphs: 135, size: 12
      pdf.move_down 65
      pdf.text "To verify this certificate, visit: #{url}", indent_paragraphs: 100, size: 8
    end
  end

end

1. We set the page size to A4 in landscape.

2. We set the background and scale it to fit the page

3. We make use of the fonts that we downloaded with our assets

4. We place the relevant information on the page

Run all your specs now. If you want to actually have a look at one of the certificates, you need to use your debugger and set a break point on one of the specs in your certificate_spec.rb

# spec/certificate_spec.rb

...
it 'adds an identifier after create' do
  expect(@certificate.identifier.size).to eq 64
end
...

The way we have set up the application and our testing frameworks, we will loose out generated certificates every time we run our test suite. That is not a behavior we desire. One way to fix that is to separate the folders in which we save the certificates depending on the environment we are in.

Go back to your certificate_generator.rb and add a Constant on top of the CertificateGenerator module and modify the output variable:

# lib/certificate_generator.rb

module CertificateGenerator

  ENV_PATH = ENV['RACK_ENV'] || 'development'

...

output = "pdf/#{ENV_PATH}/#{details[:name]}-#{details[:date]}.pdf"
...

You will need to manually create the 3 folders in your pdf folder:

$ mkdir -p pdf/production
$ mkdir -p pdf/development
$ mkdir -p pdf/test

We need to modify the cleaning strategy we configured a while back so that only the pdf/test folder is cleaned:

# features/support/database_cleaner.rb

...
Around do |scenario, block|
  DatabaseCleaner.cleaning(&block)
  FileUtils.rm_rf Dir['pdf/test/**/*.pdf']
end
...

And we also need to update our after block in the certificate_spec.rb:

# spec/certificate_spec.rb

...
describe 'Creating a Certificate' do
...
  after { FileUtils.rm_rf Dir['pdf/test/**/*.pdf'] }
...

Finally, we need to do a small refactoring in application_steps.rb, adding the subfolder /test to the path:

# features/step_definitions/application_steps.rb

...
Then(/^([^"]*) certificates should be generated$/) do |count|
  pdf_count = Dir['pdf/test/**/*.pdf'].length
  expect(pdf_count).to eq count.to_i
end
...

When you run your test now, the generated pdf's will be saved in the pdf/test folder. Your actual certificates will be saved in the pdf/development or the pdf/production folders, depending on what environment your server is running on.