Devise Registration form on any page - ruby-on-rails

Question

I'm trying to allow users to sign up for the site on my home/landing page.
I've duplicated the devise registration form into my landing page view-
<%= form_for(resource, :as => resource_name, :url => registration_path(resource_name)) do |f| %>
<%= devise_error_messages! %>
<div><%= f.label :first_name %><br />
<%= f.text_field :first_name %></div>
<div><%= f.label :last_name %><br />
<%= f.text_field :last_name %></div>
<div><%= f.label :profile_name %><br />
<%= f.text_field :profile_name %></div>
<div><%= f.label :email %><br />
<%= f.email_field :email %></div>
<div><%= f.label :password %><br />
<%= f.password_field :password %></div>
<div><%= f.label :password_confirmation %><br />
<%= f.password_field :password_confirmation %></div>
<div><%= f.submit "Sign up" %></div>
<% end %>
<%= render "devise/shared/links" %>
And I've also added the helper methods in my application_controller.rb so that I properly define the resource-
class ApplicationController < ActionController::Base
protect_from_forgery
def resource_name
:user
end
def resource
#resource ||= User.new
end
def devise_mapping
#devise_mapping ||= Devise.mappings[:user]
end
end
However I'm still getting the error undefined local variable or method resource'for #<#:0x007fa816b4b750>`
What am I missing here to properly render a REGISTRATION form on my home landing page?

Answer 1

You need to declare those controller methods as helper methods to access them from the views:
helper_method :resource, :resource_name, :devise_mapping
Just add that line inside your ApplicationController after the methods are defined.
You'll notice that the link you provided actually mentions to put this code in the application helper, not the controller... You can avoid this helper_method declaration if you do it that way.