Destroying Sessions Issue Rails 4 - ruby-on-rails

Question

I'm having problems destroying the session, the link doesn't seem to work, the URL changes in the address bar from /dashboard to /log_out but the page does not redirect to the log in page. I'm rather baffled at this.
Dashboard View:
<% if logged_in? %>
<% if request.env['mobvious.device_type'] == :mobile %>
<div class="container" style="width: 90%" >
<table>
<tr>
<td class="dash_cont">
<%= link_to "Logout", log_out_path %>
</td>
</tr>
<tr>
<td class="dash_cont">
<h1 class="form-signin-heading" >Welcome to your personal Twitter Manager!</h1>
<p>Use this site to keep track of your followers, see how many posts they've made and many more features!</p>
<p>It's a really cool site, check it out! It's free!</p><br/><br/>
</td>
</tr>
</table>
</div>
<% elsif request.env['mobvious.device_type'] == :desktop %>
<div class="container" style="width: 70%;" >
<table>
<tr>
<td class="dash_cont">
<%= link_to "Logout", log_out_path %>
</td>
</tr>
<tr>
<td class="dash_cont">
<h1 class="form-signin-heading" >Welcome to your personal Twitter Manager!</h1>
<p>Use this site to keep track of your followers, see how many posts they've made and many more features!</p>
<p>It's a really cool site, check it out! It's free!</p><br/><br/>
</td>
</tr>
</table>
</div>
<% end %>
<% else %>
<script type="text/javascript">
window.location.href="/" // put your correct path in a string here
</script>
<% end %>
Log In View:
<% if logged_in? %>
<script type="text/javascript">
window.location.href="/dashboard" // put your correct path in a string here
</script>
<% else %>
<% if request.env['mobvious.device_type'] == :mobile %>
<div class="container" style="width: 90%" >
<table>
<tr class="login-cont">
<td class="login-tcell">
<h1 class="form-signin-heading" >Log in</h1>
<%= form_tag sessions_path, class: "form-signin" do %>
<%= text_field_tag :email, params[:email], class: "form-control", autofocus: "", required: "", placeholder: "Email address" %>
<%= password_field_tag :password, nil, class: "form-control", required: "", placeholder: "Password" %></br>
<p class="button"><%= submit_tag "Log in", class: "btn btn-lg btn-primary btn-block" %></p>
<% end %>
<%= link_to "Register", "/sign_up" %>
<% if defined?(#error) %>
<div class="error">
<%= "*" + #error %>
</div>
<% end %>
<% if defined?(#notice) %>
<div class="error">
<%= "*" + #notice %>
</div>
<% end %>
</td>
</tr>
</table>
</div>
<% elsif request.env['mobvious.device_type'] == :desktop %>
<div class="container" style="width: 70%" >
<table>
<tr class="login-cont">
<td class="login-tcell">
<h1 class="form-signin-heading" >Log in</h1>
<%= form_tag sessions_path, class: "form-signin" do %>
<%= text_field_tag :email, params[:email], class: "form-control", autofocus: "", required: "", placeholder: "Email address" %>
<%= password_field_tag :password, nil, class: "form-control", required: "", placeholder: "Password" %></br>
<p class="button"><%= submit_tag "Log in", class: "btn btn-lg btn-primary btn-block" %></p>
<% end %>
<%= link_to "Register", "/sign_up" %>
<% if defined?(#error) %>
<div class="error">
<%= "*" + #error %>
</div>
<% end %>
<% if defined?(#notice) %>
<div class="error">
<%= "*" + #notice %>
</div>
<% end %>
</td>
<td class="welcome-msg white">
<br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/>
<h1 class="form-signin-heading" >Welcome to your personal Twitter Manager!</h1>
<p>Use this site to keep track of your followers, see how many posts they've made and many more features!</p>
<p>It's a really cool site, check it out! It's free!</p><br/><br/>
</td>
</tr>
</table>
</div>
<% end %>
<% end %>
Dashboard Controller:
class DashboardController < ApplicationController
helper_method :logged_in?
def new
end
def logged_in?
if defined? session[:user_id]
true
else
false
end
end
end
Sessions Controller:
class SessionsController < ApplicationController
helper_method :logged_in?
# Use this to detect device type:
# request.env['mobvious.device_type']
def new
end
def create
user = User.authenticate(params[:email], params[:password])
if user
session[:user_id] = user.id
#notice = "Logged in!"
redirect_to "/dashboard"
else
#error = "Invalid email or password"
render "new"
end
end
def destroy
session[:user_id] = nil
redirect_to root_url, :notice => "Logged out!"
end
def logged_in?
if defined? session[:user_id]
redirect_to "/dashboard"
else
redirect_to "/"
end
end
end
Routes:
TwitterApp::Application.routes.draw do
get "dashboard/new"
get "users/new"
get "sessions/new"
get "log_out" => "sessions#destroy", :as => "log_out"
get "" => "sessions#new", :as => "log_in"
get "sign_up" => "users#new", :as => "sign_up"
get "dashboard" => "dashboard#new", :as => "dashboard"
root :to => "sessions#new"
resources :users
resources :sessions
end

Answer 1

Don't use defined? to check for the presence of hash values. It will always return a non false value:
some_hash = { :some_key => nil }
defined? some_hash[:some_key] # => "method"
defined? some_hash[:i_dont_exist] # => "method"
See the docs on this for more info.
In rails you can use session[:user_id].present?. This will check that the value at that key is not blank or nil. Also a better way to delete from the session is to call delete on it: session.delete(:user_id) or session.clear if you want to wipe everything.