Check image dimensions using the Dimensions gem.

image_dimensions.rb

require 'json'

class ImageDimensions < Sinatra::Base
  get "/" do
    'API: GET /[ur_product_id].json'
  end

  get /(\d{6})\.json/ do |ur_product_id|
    content_type :json
    data = { exists: false }

    ['jpg', 'png'].each do |e|
      p = path(ur_product_id, e)

      data = {
        exists: true, ext: e, url: url(p),
        width:  Dimensions.width(p),
        height: Dimensions.height(p)
      } if File.exists? p
    end

    JSON.dump(data)
  end

  def root_path
    "/var/www/apps/ur-image-manager/shared/system/data"
  end

  def path(ur_product_id, ext = 'jpg')
    "#{root_path}/#{ur_product_id}/original/1.#{ext}"
  end

  def url(path)
    path.gsub "#{root_path}", 'http://bilduppladdning-data.ur.se'
  end
end