ruby on rails - How to render a view from a view using a condition? -

i'm testing out ror , trying figure out functionality allows users valid session skip logging in.

the login button prompts login page, whereas want make people session skip , redirected show view using conditional statement. (checks via current_user) (if need other code comment)

here's login view

<%= form_for :session, url: '/login' |s| %> <%= s.text_field :username, :placeholder => 'username' %> <%= s.password_field :password, :placeholder => 'password' %> <%= s.submit "login" %>  <% if current_user %>     <!-- write here? -->     <!-- maybe should put in controller? -->     <% end %>  <% if flash[:notice] && current_user %>     <div class="notice"><%= flash[:notice] %></div> <% end %> 

here's application controller containing current_user function. (just in case)

class applicationcontroller < actioncontroller::base protect_from_forgery with: :exception  helper_method :current_user   def current_user    @current_user ||= user.find_by(id: session[:id]) if session[:id]  end end 

not sure sessionscontroller looks like, add this:

class sessionscontroller < actioncontroller::base   before_action :check_current_user    def check_current_user     redirect_to :root, success: "you logged in." if current_user   end end 

then can remove if current_user statement in login view. , login links write:

<%= link_to 'login', new_session_path unless current_user %> 

this way login button shows if current_user nil.

also, take @ rails tutorial chapter 8: basic login more information