Question

It seems that when I run my application in production mode I am getting the following inside my console:

    /home/Desktop/Portal/app/mailers/holiday_mailer.rb:2:in 
`<class:HolidayMailer>': uninitialized constant HolidayMailer::DEFAULT_FROM (NameError)

I have looked at the following SO question Rails 3 Action Mailer uninitialized constant. It appears that I have not made that mistake as my set up is as followed:

environment.rb

require File.expand_path('../application', __FILE__)

# Initialize the rails application
Portal::Application.initialize!
ActionMailer::Base.delivery_method = :smtp
DEFAULT_FROM = "[e-mail]"

holiday mailer

class HolidayMailer < ActionMailer::Base
  default :from => DEFAULT_FROM

  def holiday_confirmation(holiday)
    @holiday = holiday
    mail(:to => holiday.user.email, :subject => "Your Absence Request")
  end
end

Holiday Controller

 def update()
    admin = User.find(current_user.role? :administrator)
    holiday = Holiday.find(params[:id])
    user = User.find(id = holiday.user_id)

    if holiday.update_attributes(params[:holiday])
      if holiday.state == "approved"
        user.absentdays = user.absentdays - (holiday.days_used).to_i
        user.save
      end
      redirect_to absence_path, :notice => "request updated!"
      #email the user to tell them the state of their holiday
      HolidayMailer.holiday_confirmation(holiday).deliver
    else
      render 'edit'
    end
  end

It seems though this is wrong

Answer 1

I don’t know why it is throwing an error in the production, but I can tell you how to fix this problem.

I replicated this scenario in my rails 3.2.11 app and I got the same error in production. There are two possible fixes.

1. Move the variable DEFAULT_FROM into environments/production.rb

2. Make an initializer file for mail settings (config/initializers/mail_settings.rb) and put this variable DEFAULT_FROM in that file.

   The second approach is neat, because its a configuration for mailer and the variable will be available in both development and production environments. Both these approaches would require you to restart your dev/deployment server.

   Hope this helps.