3scale utility to export invoice data into an XML file

invoices3scale.rb

require 'restclient'
require 'nokogiri'

# Access details to the 3scale API are grabbed from environment variables for security
DOMAIN = ENV['DOMAIN']                # Admin domain in the form: mydomain-admin.3scale.net
PROVIDER_KEY = ENV['PROVIDER_KEY']    # From your 3scale account page in the admin console

def invoices_for_month(month)

  done = false
  res = String.new
  page = 1

  while !done               # iterate over all pages for this month

    puts "Page #{page}"     # this can take a while so give updates on where we are
    url = "https://#{DOMAIN}/api/invoices.xml?provider_key=#{PROVIDER_KEY}&month=#{month}&page=#{page}&per_page=20"
    page += 1

    response = RestClient.get url
    raise Exception.new("Wrong response code (#{response.code}) in request #{url}") if response.code!=200

    document = Nokogiri::XML(response.to_str)     # this could also be refactored to use Regex and eliminate use of Nokogiri
    done = document.xpath("//pagination/@current_page").text == document.xpath("//pagination/@total_pages").text

    response_string=response.to_str.delete("\n")    # strip any newlines which would screw up the .split operation

    # we cannot just concatenate results from the pagination because the metadata would mess up the xml schema
    # strip out the metadata, from the raw invoice content

    parsed_response=response_string.split(/(<\?xml version=\"1.0\" encoding=\"UTF-8\"\?><invoices version=\"1.0\"><pagination.*?\/>)(.*)(<\/invoices>)\z/)
    invoice_content= parsed_response[2]         # grab the raw invoice content from the .split operation

    res << invoice_content                      # concatenate with results from previous pages
  end

  return res

end

def save_month(month, invoices)                 # option for intermediate save of a single month of results in case of any network issues
  File.open( "#{month}.xml" , "w" ) do |file|
    file.puts "<invoices>#{invoices}</invoices>"
  end
end

##----------------------------------------------------------
##--Export invoice date from 3scale for multiple months-----
##--Save to an XML file which can easily be read------------
##--into Microsoft Excel------------------------------------
##----------------------------------------------------------

puts "May"                                       # give a progress update since this will take a while
invoices_may = invoices_for_month '2014-05'      # get invoices for desired month
save_month "may", invoices_may                   # do an intermediate save

puts "Jun"
invoices_jun = invoices_for_month '2014-06'
save_month "jun", invoices_jun

puts "Jul"
invoices_jul = invoices_for_month '2014-07'
save_month "jul", invoices_jul

puts "Done"

# after all months are processed contactenate them and write them out to file as XML
# note we need to create the root element for valid XML

File.open( "output.xml" , "w" ) do |file|
  file.puts "<invoices>#{invoices_may}#{invoices_jun}#{invoices_jul}</invoices>"
end