Simple Auth

SimpleAuth is an authentication library to be used when everything else is just too complicated.

This library only handles session. You have to implement the authentication strategy as you want (e.g. in-site authentication, OAuth, etc).

Rails 4.2+ running over Ruby 2.1+ is required.

Installation

Just the following line to your Gemfile:

gem "simple_auth"

Then run rails generate simple_auth:install to copy the initializer file.

Usage

The initializer will install the required helper methods on your controller. So, let's say you want to support user and admin authentication. You'll need to specify the following scope.

# config/initializers/simple_auth.rb
SimpleAuth.setup do |config|
  config.scopes = %i[user admin]
  config.login_url = proc { login_path }
  config.logged_url = proc { dashboard_path }

  config.install_helpers!
end

Session is valid only when Controller#authorized_#{scope}? method returns true, which is the default behavior. You can override these methods with your own rules; the following example shows how you can authorize all e-mails from @example.com to access the admin dashboard.

class Admin::DashboardController < ApplicationController
  private
  def authorized_admin?
    current_user.email.match(/@example.com\z/)
  end
end

So, how do you set up a new user session? That's really simple, actually.

class SessionsController < ApplicationController
  def new
  end

  def create
    @user = User.find_by_email(params[:email])

    if @user.try(:authenticate, params[:password])
      SimpleAuth::Session.create(scope: "user", session: session, record: @user)
      redirect_to return_to(dashboard_path)
    else
      flash[:alert] = "Invalid username or password"
      render :new
    end
  end

  def destroy
    reset_session
    redirect_to root_path
  end
end

First thing to notice is that simple_auth doesn't care about how you authenticate. You could easily set up a different authentication strategy, e.g. API tokens. The important part is assign the record: and scope: options. The return_to helper will give you the requested url (before the user logged in) or the default url.

Same thing applies to destroying a session. You can just reset it, calling reset_session.

You can restrict access by using 2 macros. Use redirect_logged_#{scope} to avoid rendering a page for logged user.

class SignupController < ApplicationController
  before_action :redirect_logged_user
end

Use require_logged_#{scope} to enforce authenticated access.

class DashboardController < ApplicationController
  before_action :require_logged_user
end

"So which helpers are defined?", you ask. Just three simple helpers.

#{scope}_logged_in?    # e.g. user_logged_in? (available in controller & views)
current_#{scope}       # e.g. current_user    (available in controller & views)
#{scope}_session       # e.g. user_session    (available in controller & views)

Translations

These are the translations you'll need:

en:
  simple_auth:
    user:
      need_to_be_logged_in: "You need to be logged"
      not_authorized: "You don't have permission to access this page"

If you don't set these translations, a default message will be used.

Maintainer

• Nando Vieira (http://nandovieira.com)

License:

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.