Prince is a command line program, available for whatever platform you’re probably running.
It can take a variety of inputs including files on disk, or even HTTP urls.
Here is a very simple Ruby library to call Prince and a helper module to include on my Rails controllers. I store them both in the lib folder of my Rails application.
Here’s the full helper, slightly modified for simplicity:
Code:
# We use this chunk of controller code all over to generate PDF files.
#
# To stay DRY we placed it here instead of repeating it all over the place.
#
module PdfHelper
require 'prince'
private
# Makes a pdf, returns it as data...
def make_pdf(template_path, pdf_name, landscape=false)
prince = Prince.new()
# Sets style sheets on PDF renderer.
prince.add_style_sheets(
"#{RAILS_ROOT}/public/stylesheets/application.css",
"#{RAILS_ROOT}/public/stylesheets/print.css",
"#{RAILS_ROOT}/public/stylesheets/prince.css"
)
prince.add_style_sheets("#{RAILS_ROOT}/public/stylesheets/prince_landscape.css") if landscape
# Render the estimate to a big html string.
# Set RAILS_ASSET_ID to blank string or rails appends some time after
# to prevent file caching, ****ing up local - disk requests.
ENV["RAILS_ASSET_ID"] = ''
html_string = render_to_string(:template => template_path, :layout => 'document')
# Make all paths relative, on disk paths...
html_string.gsub!("src=\"", "src=\"#{RAILS_ROOT}/public")
# Send the generated PDF file from our html string.
return prince.pdf_from_string(html_string)
end
# Makes and sends a pdf to the browser
#
def make_and_send_pdf(template_path, pdf_name, landscape=false)
send_data(
make_pdf(template_path, pdf_name, landscape),
:filename => pdf_name,
:type => 'application/pdf'
)
end
end
This simple module has two methods. Both take an ERB template path as an argument, then a pdf file name.
Make_pdf renders the template to a string, then does some modifications to make all requests within local.
When it’s done it returns the PDF file as data. Nothing is rendered to disk. This method is useful for not only sending the PDF file to the client (as in make_and_send_pdf), but when generating PDF files for email attachments.
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