mailing list using JQuery, Sinatra, HAML fails with "undefined" email address

Question

Somehow, a simple form I have to sign up for a mailing list (which adds an email to a Google Apps Group, using gdatav2rubyclientlib) seems to fail occasionally. The form is submitted via POST through jQuery, and the Sinatra app (running on nginx/Passenger) handles the POST and emails me a confirmation. Occasionally, I get emails that "undefined" signed up. Somehow, the value the user types in is getting lost, but I'm not sure how or why. . .

Here's the HAML form from which the POST originates:

%li.sidebar-section
  %span#mailing-list-slug
    get on our mailing list
    <br/>
  %form{:id => "mailing_list_signup", :method => "post", :action => "/mailinglist/signup/the.grapevine"}
    %input{:type => 'text', :name => 'email', :value => "enter your email&hellip;", :id => 'mailing-list-signup'}
    %input{:id => "mailing_list_signup_button", :type => 'submit', :value => 'sign up'}
    #thanks
      thanks!  you're in!

Here's the Javascript that makes the POST: $('#mailing_list_signup_button').click(function () { var email_address = $('input#mailing-list-signup').val();

  $.ajax({  
    type: "POST",  
    url: "/mailinglist/signup/the.grapevine",
    data: "email=" + email_address,
    success: function() {
      $('#thanks').show('slow');
    }
  });

  var email_address = $('input#email').val();

  $.post("/mailinglist/signup/the.grapevine", 
    $('form#mailing_list_signup').serialize(), function(result){alert(email_address);});
    return false; });
  });

Here's my route handler for the POST request

post '/mailinglist/signup/:list' do
  adminuser = "ADMINUSERNAME"
  password  = "PASSWORD"
  email = params[:email]
  mailing_list = params[:list]
  myapps = ProvisioningApi.new(adminuser,password)
  myapps.add_member_to_group(email, mailing_list)
  gmail(:to => 'MYEMAIL', :subject => "HEY HEY GUESS WHAT, #{params[:email]} JUST SIGNED UP FOR #{params[:list]}!", :body => "Totally not joking--")
end

Any thoughts would be appreciated!

Answer 1

I would add validation to the email address field on the server side at least, but you can do initial verification on the client side as well (using a regex or jQuery Validation).

If the email field does not contain a valid email address, do not submit the request to add the member.