Add possibility to add an attachment to an invoice #345

app/models/invoice.rb

@@ -1,3 +1,5 @@
+require 'filemagic'
+
 class Invoice < ActiveRecord::Base
 
   belongs_to :supplier
@@ -7,12 +9,27 @@ class Invoice < ActiveRecord::Base
 
   validates_presence_of :supplier_id
   validates_numericality_of :amount, :deposit, :deposit_credit
+  validate :valid_attachment
 
   scope :unpaid, -> { where(paid_on: nil) }
 
+  attr_accessor :delete_attachment
+
   # Replace numeric seperator with database format
   localize_input_of :amount, :deposit, :deposit_credit
 
+  def attachment=(incoming_file)
+    self.attachment_data = incoming_file.read
+    self.attachment_mime = FileMagic.new(FileMagic::MAGIC_MIME).buffer(self.attachment_data)
+  end
+
+  def delete_attachment=(value)
+    if value == '1'
+      self.attachment_data = nil
+      self.attachment_mime = nil
+    end
+  end
+
   def user_can_edit?(user)
     user.role_finance? || (user.role_invoices? && !self.paid_on && self.created_by.id == user.id)
   end
@@ -21,4 +38,15 @@ class Invoice < ActiveRecord::Base
   def net_amount
     amount - deposit + deposit_credit
   end
+
+  protected
+
+  def valid_attachment
+    if attachment_data
+      mime = MIME::Type.simplified(attachment_mime)
+      unless ['application/pdf', 'image/jpeg'].include? mime
+        errors.add :attachment, I18n.t('model.invoice.invalid_mime', :mime => mime)
+      end
+    end
+  end
 end