Question

I am new to Ruby on Rails(rails 3). I am having a form with three fields and among these three field, one field is to upload files(rar/tar/zip). I would like to know the way to validate (server side) such form that allow user:-

1. Fill in all three fields.
2. Uploaded file should be either rar/tar/zip.
3. Uploaded file should not exceed 2MB in size.

Answer 1

U can use the paperclip gem for uploading a file.

class User < ActiveRecord::Base
  attr_accessible :avatar
  has_attached_file :avatar, :styles => { :medium => "300x300>", :thumb => "100x100>" }
end

there are validations like

validates_attachment :avatar, :presence => true,
  :content_type => { :content_type => "image/jpg" },
  :size => { :in => 0..10.kilobytes}

see https://github.com/thoughtbot/paperclip for more info.