Question

I got a little ruby app going and I’m having trouble with one part. When I invoke the create view I use a form which passes some parameters in a post request. The only parameter I care about is the id field which I then use in the code to do something useful in the model. The problem begins when I try to take the newly created object that is formed from the CREATE request and immediately call a class method on it. The class method I have made for the object is called create and I would like to call that method from the initialize method. When I remove the call to the create method from the initialize method everything runs smoothly which demonstrates that I’ve got it mostly right.

POST Request Parameters:

{"utf8"=>"✓",
 "authenticity_token"=>"fCQw3Pegyv069jO0tZ4eY5buslyAM/r8yrG7phyoJqI=",
 "id"=>"20110806",
 "commit"=>"Create"}

Relevant part of Reports controller

  def create
    @report = Report.new(params[:id], Time.now)
  end

Initialize method in the Report class which is also a model and is declared as a resource in the routes file with only show, new, create as controller actions

class Report
  attr_accessor :date, :file_path, :time_created
  REPORT_DIR = "/home/ben/Desktop"
  date_format = "%Y%m%d"

      def initialize(report_date, timestamp)
        @date = report_date
        @file_path = REPORT_DIR+"/#{date}-orders.txt"
        @time_created = timestamp
        create unless FileTest.exist?(@file_path)
      end

def create
  @orders = ShopifyAPI::Order.find(:all, :params => { :created_at_min => "#{@date} 00:00", :created_at_max => "#{@date} 23:59", :order => "created_at DESC" })

  File.open(@file_path, 'w') { |f| 

    @orders.each do |order|

      # begin line 1
      line1 = "850   00000000000"       # standard way to start the line
      line1 += order.id.to_s            # adding the order id
      oid_len = order.id.to_s.length        # calculating the length of the   order number to
      no_spaces = 22 - oid_len      # place the appropriate number of white space
      no_spaces.times do
        line1 += " "
      end
      line1+= "PO               "       # PO + 15 spaces
      line1+= "PARTNER KEY                   "# this line is 30 chars total, readjust when partner key comes in
      line1+= "0000020552078    0001     004010                     X X401                                        P P"
      f.write (line1+"\n")          # end of line 1

      # begin line 2
      line2 = "850   BEG0020000000NE"       # standard way to start the line
      line2 += order.id.to_s            # add the order id
      no_spaces = 52 - oid_len      # calculate the necessary amount of spaces
      no_spaces.times do
        line2 += " "
      end
      line2 += order.created_at.strftime(date_format) # add the order creation date
      f.write (line2+"\n")          # end of line 2

      # begin line 3
      line3 = "850   DTM017000000"      # standard way to start the line
      line3 += "02"             # standard
      line3 += order.created_at.strftime(date_format)   # order creation date
      f.write (line3+"\n")          # end of line 3

      # begin line 4
      line4 = "850   N1 04700000"       # standard way to start the line
      line4 += "ST "                # standard Ship to qualifier with a space
      full_name = order.customer.first_name+" "+ order.customer.last_name # get the customers full name
      name_len = full_name.length       # determine the length of the name
      no_spaces = 60 - name_len             # to calculate the number of spaces needed
      line4 += full_name
      no_spaces.times do
        line4 += " "
      end
      line4 += "9 "
      line4 += order.customer.id.to_s       # add the customer ID
      f.write (line4+"\n")          # end of line 4

      # begin line 5
      line5 = "850   N3 05000000"       # standard way to start the line
      line5 += order.shipping_address.address1 # add the first line of the billing address
      f.write (line5+"\n")          # end of line 5

      # begin line 6
      line6 = "850   N4 05100000"       # standard way to start the line
      line6 += order.shipping_address.city  # add the city
      city_len = order.shipping_address.city.length # get the length to calculate the needed white space
      no_spaces = 30 - city_len
      no_spaces.times do
        line6 += " "
      end
      line6 += order.shipping_address.province_code # add the province code
      line6 += order.shipping_address.zip   # add the zip/postal code
      f.write (line6+"\n")          # end of line 6

      # begin line 7 (this line repeats per line item)
      line_no = 0               # create a line counter
      order.line_items.each do |line_item|
        line_no = line_no + 1           # increment the line number
        line7 = "850   PO108300000"     # standard way to start the line
        line7 += line_no.to_s           # add the line number to the line
        no_spaces = 20 - line_no.to_s.length    # calculate the number of spaces to append
        no_spaces.times do
          line7 += " "
        end
        no_zeroes = 16 - line_item.quantity.to_s.length # prepend the quantity with zeroes
        no_zeroes.times do
          line7 += "0"
        end
        line7 += line_item.quantity.to_s    # add the quantity to the line
        line7 += "EA"               # standard symbols
        price = '%.2f' % line_item.price    # get the price formatted ##.##
        price_len = price.to_s.length - 1   # figure out how many chars the price is - the decimal
        price.to_s =~ /([0-9]+)\.([0-9]{2})/    # convert the price to a string and break it up
        dollars = $1                # get the dollar amount from the regex
        cents   = $2                        # get the cents amount from the regex
        no_zeroes = 17 - price_len      # calculate the number of zeroes to place after the 2 / before the price
        line7 += "2"                # 2 denotes the position of the decimal in the price
        no_zeroes.times do
          line7 += "0"          # add the zeroes in the middle
        end
        line7 += dollars            # add the dollar amount
        line7 += cents          # add the cent amount
        line7 += "  PI"         # standard symbols
        line7 += line_item.sku.to_s     # add the SKU
        no_spaces = 48 - line_item.sku.to_s.length # calculate the number of spaces needed
        no_spaces.times do
          line7 += " "
        end
        line7 += "VN"               # standard symbols
        line7 += line_item.sku.to_s     # add the SKU again
        f.write (line7+"\n")            
      end                   # end of the line item

      # begin line 8
      line8 = "850   CTT204"
      no_zeroes = 12 - line_no.to_s.length
      no_zeroes.times do
        line8 += "0"
      end
      line8 += line_no.to_s
      f.write(line8+"\n")

      # begin line 9
      line9 = "850   AMT20500000TT 2000000000000058151"
      f.write(line9+"\n")

    end     # end of the order
  }     # closing the file
  @time_created = Time.now
end     # end of create method
end

Error report:

Started POST "/reports" for 127.0.0.1 at 2011-08-09 02:40:17 -0400
  Processing by ReportsController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"fCQw3Pegyv069jO0tZ4eY5buslyAM/r8yrG7phyoJqI=", "id"=>"20110805", "commit"=>"Create"}
Completed 500 Internal Server Error in 9ms

NoMethodError (undefined method `path' for nil:NilClass):
  app/models/report.rb:35:in `create'
  app/models/report.rb:10:in `initialize'
  app/controllers/reports_controller.rb:8:in `new'
  app/controllers/reports_controller.rb:8:in `create'

Answer 1

I found the problem. Since the app is working within the framework of a shopify app the Reports controller needs an additional method to make sure the user is authenticated before requests can be made to the API. Very Shopify specific problem and I appreciate everyone for pitching in. Without your help I’d be nowhere, thanks for helping me reason.