Basic structure of a Rails API with Backbone frontend

gistfile1.rb

###
# Rails Controller to manage an NFL team's fans
# from a email signup form
###
class FansController < ActionController::Base
    
  def create
    @fan = Fan.new(fan_params)

    respond_to do |format|
      if @fan.save
        format.json { render json: :success }
      else
        format.json { render json: @fan.errors, status: :unprocessable_entity }
      end
    end
  end
  
  private
    def fan_params
      params.require(:fan).permit(:email, :zip)
    end
end

###
# Backbone model and view to interact with the Rails API
###
$(function() {
  var Fan = Backbone.Model.extend({
    defaults: {
      email: '',
      zip: ''
    },
    urlRoot: '/fan',
    updateAttrs: function(attrs, callbacks) {
      this.save(attrs, callbacks);
    },
    errors: [],
    validate: function(attrs, options) {
      this.errors = [];
      if (!(/\S+@\S+/.test(attrs.email))) {
        this.errors.push({name: 'email', message: 'Please enter a valid email address'});
      }
      if (!(/[\w\s]{5,10}/.test(attrs.zip))) {
        // we'll quietly accept Canadian codes too
        this.errors.push({name: 'zip', message: 'Please enter a valid zip code'});
      }
      return this.errors.length > 0 ? this.errors : false;
    }
  });

  var fan = new Fan();

  var FanView = Backbone.View.extend({
    initialize: function() {
      this.model.on('invalid', this.callbacks.error, this);
    },
    render: function() {
      var attrs = this.model.toJSON();
      var source = $('#fan-template').html();
      var template = Handlebars.compile(source);
      var html = template(attrs);
      this.$el.html(html);
      return this;
    },
    events: {
      'submit form': 'createFan'
    },
    createFan: function(e) {
      e.preventDefault();
      var email = this.$('#email').val();
      var zip = this.$('#zip').val();
      this.model.updateAttrs({email: email, zip: zip}, this.callbacks);
    },
    callbacks: {
      success: function() {
        $('#success').show();
        $('#fail').hide();
      },
      error: function(results, errors) {
        $('#success').show();
        $('#fail').hide();
      }
    }
  });

  var fanView = new FanView({model: fan});
  var $fanForm = $('#fan-form-container');
  $fanForm.html(fanView.render().el);
});

###
# handlebars template (in Jade)
###
script(id="fan-template", type="text/x-handlebars-template")
  form(action='/fan', method='post')
    input.txt(name='email', id='email', type='email', required, placeholder='your email address')
    input.txt(name='zipcode', id='zip', type='text', size='5', maxlength='10', required, placeholder='your zipcode *')
    input.submit-form(type='submit', value='sign me up!')
  #success.hidden.alert.alert-error
    Success!
  #fail.hidden.alert.alert-success
    Oops, there was a problem
    

###
# template view
###
body
  #fan-form-container