Rails pass request.subdomain into a custom Devise mailer layout

Question

I need to adapt the forgot password instructions to handle a subdomain. I have followed the instructions on the devise site to override the mailer, controller and add a subdomain helper etc. as listed:

controllers/password_controller.rb

class PasswordsController < Devise::PasswordsController
  def create
    @subdomain = request.subdomain
    super
  end
end

routes.rb

devise_for :users, controllers: { passwords: 'passwords' }

devise.rb

config.mailer = "UserMailer"

mailers/user_mailer.rb

class UserMailer < Devise::Mailer
  helper :application # gives access to all helpers defined within `application_helper`.

  def confirmation_instructions(record, opts={})
    devise_mail(record, :confirmation_instructions, opts)
  end

  def reset_password_instructions(record, opts={})
    devise_mail(record, :reset_password_instructions, opts)
  end

  def unlock_instructions(record, opts={})
    devise_mail(record, :unlock_instructions, opts)
  end

end

views/user_mailer/reset_password_instructions.html.erb

<p>Hello <%= @resource.email %>!</p>

<p>Someone has requested a link to change your password. You can do this through the link below.</p>
<p><%= link_to 'Change my password', edit_password_url(@resource, :reset_password_token => @resource.reset_password_token, :subdomain => @subdomain) %></p>

<p>If you didn't request this, please ignore this email.</p>
<p>Your password won't change until you access the link above and create a new one.</p>

helpers/subdomain_helper.rb

module SubdomainHelper
  def with_subdomain(subdomain)
    subdomain = (subdomain || "")
    subdomain += "." unless subdomain.empty?
    host = Rails.application.config.action_mailer.default_url_options[:host]
    [subdomain, host].join
  end

  def url_for(options = nil)
    if options.kind_of?(Hash) && options.has_key?(:subdomain)
      options[:host] = with_subdomain(options.delete(:subdomain))
    end
    super
  end
end

application.rb

config.to_prepare do
  Devise::Mailer.class_eval do 
    helper :subdomain
  end
end

Now, this code is all working but it just can't get the value of @subdomain in the mailer view. If I replace @subdomain with a hard-coded string then the correct url is passed in the email so I know the code is all correct.

How do I get the instance variable @subdomain defined in the controller into the mailer view?

Answer 1

I've found a way. I will think if I can find a better way without having to monkey patch stuff and having to chain it up the subdomain.

Basically, I override the controller doing this:

class PasswordsController < Devise::PasswordsController
  def create
    subdomain = request.subdomain
    @user = User.send_reset_password_instructions(params[:user].merge(subdomain: subdomain))

    if successfully_sent?(@user)
      respond_with({}, :location => after_sending_reset_password_instructions_path_for(:user))
    else
      respond_with(@user)
    end
  end
end

Also, I had to monkey patch this methods on my user model:

def send_reset_password_instructions(subdomain)
  generate_reset_password_token! if should_generate_reset_token?
  send_devise_notification(:reset_password_instructions, subdomain: subdomain)
end

def self.send_reset_password_instructions(attributes={})
  recoverable = find_or_initialize_with_errors(reset_password_keys, attributes, :not_found)
  recoverable.send_reset_password_instructions(attributes[:subdomain]) if recoverable.persisted?
  recoverable
end

And finally, I had to monkey patch devise_mail methods, which lives inside Devise.

  Devise::Mailer.class_eval do
    def devise_mail(record, action, opts={})
      initialize_from_record(record)
      initialize_subdomain(opts.delete(:subdomain)) # do this only if the action is to recover a password.
      mail headers_for(action, opts)
    end

    def initialize_subdomain(subdomain)
      @subdomain = instance_variable_set("@subdomain", subdomain)
    end
  end

Doing this, the @subdomain variable appeared on the mailer template. I'm not happy with this solution, but this is a starting point. I will think on any improvements on it.

Answer 2

Here's an updated answer that I think solves your question nicely - https://github.com/plataformatec/devise/wiki/How-To:-Send-emails-from-subdomains

In my case my subdomain was stored in my Accounts table and here's what I did to allow me to use @resource.subdomain in my devise mailer views

class User < ActiveRecord::Base  
  belongs_to :account

  # This allows me to do something like @user.subdomain
  def subdomain
    account.subdomain
  end
end

class Account < ActiveRecord::Base
  has_many :users
end

Answer 3

For devise 3.1 the above monkey patching in user model can be like below. This in the case your subdomain is stored in a seperate model(say tenants) that has no relation to other models like accounts, users what ever it be..(find like current_tenant.subdomain)

def send_reset_password_instructions(subdomain)
  raw, enc = Devise.token_generator.generate(self.class, :reset_password_token)

  self.reset_password_token   = enc
  self.reset_password_sent_at = Time.now.utc
  self.save(:validate => false)

  send_devise_notification(:reset_password_instructions, raw, {subdomain: subdomain})
  raw
end

def self.send_reset_password_instructions(attributes={})
  recoverable = find_or_initialize_with_errors(reset_password_keys, attributes, :not_found)
  recoverable.send_reset_password_instructions(attributes[:subdomain]) if recoverable.persisted?
  recoverable
end