how to enable only authenticated users to create new users - ruby-on-rails

Question

I guess the title is self explanatory...how do I make only authenticated users to create a user with devise?
when I try to add a new one (when authenticated), devise says that I'm alreade authenticated
any workaround for this?
thanks a lot
edit: as requested, my code
user form
<% if #user == current_user %>
<i class="icon-info-sign"> </i><i>Após alterar seus dados, você terá de fazer login novamente</i>
<% end %>
<%= form_for(#user, :html => { :class => "well form-horizontal"}) do |f| %>
<% if #user.errors.any? %>
<div class="alert alert-error">
<h2><%= pluralize(#user.errors.count, "erro") %>
<% if #user.errors.count == 1 %> impede
<% else %>
impedem
<% end %>
a continuação:</h2>
<ul>
<% #user.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<label>Nome</label><%= f.text_field :nome %>
<label>E-mail</label><%= f.email_field :email %>
<% if #user == current_user or #user.created_at == nil%>
<label>Senha</label><%= f.password_field :password %>
<% end %>
<div>
<br />
<button class="btn" type="submit">
Salvar alterações
</button>
</div>
<% end %>
part of users controller
before_filter :authenticate_user!
def index
#users = User.all
respond_to do |format|
format.html # index.html.erb
format.json { render json: #users }
end
end
# GET /users/1
# GET /users/1.json
def show
#user = User.find(params[:id])
respond_to do |format|
format.html # show.html.erb
format.json { render json: #user }
end
end
# GET /users/new
# GET /users/new.json
def new
#user = User.new
respond_to do |format|
format.html # new.html.erb
format.json { render json: #user }
end
end
# GET /users/1/edit
def edit
#user = User.find(params[:id])
end
# POST /users
# POST /users.json
def create
#user = User.new(params[:user])
respond_to do |format|
if #user.save
format.html { redirect_to #user, notice: 'User was successfully created.' }
format.json { render json: #user, status: :created, location: #user }
else
format.html { render action: "new" }
format.json { render json: #user.errors, status: :unprocessable_entity }
end
end
end
# PUT /users/1
# PUT /users/1.json
def update
#user = User.find(params[:id])
respond_to do |format|
if #user.update_attributes(params[:user])
format.html { redirect_to #user, notice: 'User was successfully updated.' }
format.json { head :no_content }
else
format.html { render action: "edit" }
format.json { render json: #user.errors, status: :unprocessable_entity }
end
end
end
application controller
class ApplicationController < ActionController::Base
protect_from_forgery
def after_sign_in_path_for(resource)
return request.env['omniauth.origin'] || stored_location_for(resource) || painel_path
end
end
part of routes
App::Application.routes.draw do
resources :acampantes
devise_for :users, :skip => [:registrations]
resources :profiles
resources :eventos do
resources :acampantes
end
# aqui tem um has_many, mas não precisa de nested routes
resources :noticias
resources :users#, :as => "usuarios"

Answer 1

The ideal way to do it would be to override registrations_controller.rb (as shown here) and skipping the before_filter check for the new and create action. I tried to do it myself, but unfortunately, I couldn't get it right.
Another way to do it, which worked for me, would be to create a separate User controller aside from the Registrations controller provided by Devise:
class UsersController < ApplicationController
before_filter :authenticate_user!
def new
#user = User.new
end
def create
#user = User.new(params[:user])
if #user.save
flash[:success] = "User saved"
redirect_to #user
else
render 'new'
end
end
end
# routes.rb
ApplicationName::Application.routes.draw do
devise_for :users
resources :users, :only => [:new, :create]
end
Then make a form for the new action:
# app/views/users/new.html.erb
<%= form_for(#user) do |f| %>
<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 %>
The problem with this approach is that the routes provided by Devise for signing-up still exists. A solution for that would be to prevent Devise from generating routes involving registration:
# routes.rb
devise_for :users, :skip => [:registrations]
This means that you are going to ignore the Registrations module completely and make your own. I got this idea from the Bare-bone, stripped-down Devise tutorial. Take note that you should make the controller actions and views to replace the ones provided by the registrations module of Devise. This includes new, edit, create, update, and destroy.