deleting tar for products on update

app/models/product.rb

@@ -16,10 +16,26 @@ class Product < ActiveRecord::Base
 
   scope :recent, order("name ASC")
 
+  before_save :destroy_tar?
+
+  def delete_tar
+    @delete_tar ||= "0"
+  end
+
+  def delete_tar=(value)
+    @delete_tar = value
+  end
+
   protected
 
+    def destroy_tar?
+      self.tar.clear if @delete_tar == "1"
+    end
+
     def merge_tar_errors
       errors[:tar] += errors[:tar_content_type]
       errors[:tar_content_type] = []
     end
+
+
 end

app/views/products/_form.html.haml

@@ -14,8 +14,14 @@
   = f.label :menu, t("activerecord.attributes.product.menu"), :class => :label
   = f.text_area :menu, :class => 'text_field', :cols => 80
 .group
-  = f.label :tar, t("activerecord.attributes.product.tar"), :class => :label
-  = f.file_field :tar, :class => 'file_field'
+  %p
+    = f.label :tar, t("activerecord.attributes.product.tar"), :class => :label
+    = f.file_field :tar, :class => 'file_field'
+  %p
+  - if @product.tar?
+    = link_to @product.tar_file_name, @product.tar.url
+    = f.check_box :delete_tar
+    = f.label :delete_tar, t('layout.delete')
 
 .group.navform.wat-cf
   %button.button{:type => "submit"}