Question

My app has a simple signup where the user types in his/her email address and POSTs the request. The request is then sent to my server using AJAX, an email is sent to the user’s email using ActionMailer, and a thank you message is rendered using jQuery. With the code I have currently, the thank-you message is rendered only AFTER the email is sent, so it takes some time for the thank-you message to show. However, I’d like the thank-you message to be rendered first, and the email to be sent to the user in the background, so that the user can immediately know that his/her email was saved. Is there a way to process email in the background with Rails?

Below is my current code.
In users_controller.rb

def create
  @user = User.new(params[:user])

  respond_to do |format|
    if @user.save
      format.html { redirect_to @user, notice: 'Thank you for signing up!' }
      format.js
      format.json { render json: @user, status: :created, location: @user }
      Notifier.email_saved(@user).deliver
    else
      format.html { render action: "new" }
      format.json { render json: @user.errors, status: :unprocessable_entity }
    end
  end
end

In mailers/notifier.rb

class Notifier < ActionMailer::Base
  default from: "First Last <[e-mail]>"

  def email_saved(user)
    @email = user.email
    mail to: @email, subject: 'Auto-Response: Thank you for signing up'
  end
end

In users/create.js.erb

$("<div class='alert alert-success'>Thank you for showing your interest! A confirmation email will be sent to you shortly.</div>").insertAfter("#notice");

Answer 1

If you want to send mail only, you should use better “Resque” or “Delayed Job” than “Ajax”.

#271 Resque – RailsCasts http://railscasts.com/episodes/271-resque

Delayed Job (DJ) | Heroku Dev Center https://devcenter.heroku.com/articles/delayed-job

But if you want to send mail using Ajax, please use below snippets as a reference.

#app/controllers/users_controller.rb
def create
  @user = User.new(params[:user])

  respond_to do |format|
    if @user.save
      format.html { redirect_to @user, notice: 'Thank you for signing up!', sign_up_flag: 1 }
      format.js
      format.json { render json: @user, status: :created, location: @user }
    else
      format.html { render action: "new" }
      format.json { render json: @user.errors, status: :unprocessable_entity }
    end
  end
end

def send_mail(user_id)
    begin
      user = User.find(user_id)
      Notifier.sign_up_mail(user.email).deliver
      render :nothing => true, :status => 200
    rescue
      render :nothing => true, :status => 500
    end
end



#app/mailers/notifier.rb
class Notifier < ActionMailer::Base
  default from: "First Last <[e-mail]>"

  def sign_up_mail(email)
    mail to: email, subject: 'Auto-Response: Thank you for signing up'
  end
end



#app/views/???.html.erb
<% if @sign_up_flag == 1 %>
  $(document).ready(function(){
    $.ajax({
      type: "POST",
      url:  "/sendmail",
      data: "",
      success : function(){},
      error : function() {}
    });
  });
<% end %>



#config/routes.rb
  post '/sendmail' => 'users#send_mail'

Thanks.