OmniAuth Identity

The OmniAuth Identity gem provides a way for applications to utilize a
traditional login/password based authentication system without the need
to give up the simple authentication flow provided by OmniAuth. Identity
is designed on purpose to be as featureless as possible: it provides the
basic construct for user management and then gets out of the way.

Usage

This can be a bit hard to understand the first time. Luckily, Ryan Bates made
a Railscast about it!

You use omniauth-identity just like you would any other OmniAuth provider: as a
Rack middleware. The basic setup for a email/password authentication would
look something like this:

use OmniAuth::Builder do
  provider :identity, :fields => [:email]
end

Next, you need to create a model (called Identity by default) that will be
able to persist the information provided by the user. Luckily for you, there
are pre-built models for popular ORMs that make this dead simple.

Note: OmniAuth Identity is different from many other user authentication
systems in that it is not built to store authentication information in your primary
User model. Instead, the Identity model should be associated with your
User model giving you maximum flexibility to include other authentication
strategies such as Facebook, Twitter, etc.

ActiveRecord

Just subclass OmniAuth::Identity::Models::ActiveRecord and provide fields
in the database for all of the fields you are using.

class Identity < OmniAuth::Identity::Models::ActiveRecord
  # Add whatever you like!
end

Mongoid

Include the OmniAuth::Identity::Models::Mongoid mixin and specify
fields that you will need.

class Identity
  include Mongoid::Document
  include OmniAuth::Identity::Models::Mongoid

  field :email, type: String
  field :name, type: String
  field :password_digest, type: String
end

MongoMapper

Include the OmniAuth::Identity::Models::MongoMapper mixin and specify
fields that you will need.

class Identity
  include MongoMapper::Document
  include OmniAuth::Identity::Models::MongoMapper

  key :email, String
  key :name, String
  key :password_digest, String
end

DataMapper

Include the OmniAuth::Identity::Models::DataMapper mixin and specify
fields that you will need.

class Identity
  include DataMapper::Resource
  include OmniAuth::Identity::Models::DataMapper

  property :id,              Serial
  property :email,           String
  property :password_digest, Text

  attr_accessor :password_confirmation

end

CouchPotato

Include the OmniAuth::Identity::Models::CouchPotatoModule mixin and specify fields that you will need.

class Identity
  include CouchPotato::Persistence
  include OmniAuth::Identity::Models::CouchPotatoModule

  property :email
  property :password_digest

  def self.where search_hash
    CouchPotato.database.view Identity.by_email(:key => search_hash)
  end

  view :by_email, :key => :email
end

Once you've got an Identity persistence model and the strategy up and
running, you can point users to /auth/identity and it will request
that they log in or give them the opportunity to sign up for an account.
Once they have authenticated with their identity, OmniAuth will call
through to /auth/identity/callback with the same kinds of information
it would had the user authenticated through an external provider.
Simple!

Custom Auth Model

To use a class other than the default, specify the :model option to a
different class.

use OmniAuth::Builder do
  provider :identity, :fields => [:email], :model => MyCustomClass
end

Customizing Registration Failure

To use your own custom registration form, create a form that POSTs to
'/auth/identity/register' with 'password', 'password_confirmation', and your
other fields.

<%= form_tag '/auth/identity/register' do, f, %>
  <h1>Create an Account</h1>
  <%= text_field_tag :email %>
  <%= password_field_tag :password %>
  <%= password_field_tag :password_confirmation %>
  <%= submit_tag %>
<% end %>

Beware not to nest your form parameters within a namespace. This strategy
looks for the form parameters at the top level of the post params. If you are
using simple_form, then you
can avoid the params nesting by specifying :input_html.

<%= simple_form_for @identity, :url => '/auth/identity/register' do, f, %>
  <h1>Create an Account</h1>
  <%# specify :input_html to avoid params nesting %>
  <%= f.input :email, :input_html => {:name => 'email'} %>
  <%= f.input :password, :as => 'password', :input_html => {:name => 'password'} %>
  <%= f.input :password_confirmation, :label => "Confirm Password", :as => 'password', :input_html => {:name => 'password_confirmation'} %>
  <button type='submit'>Sign Up</button>
<% end %>

Next you'll need to let OmniAuth know what action to call when a registration
fails. In your OmniAuth configuration, specify any valid rack endpoint in the
:on_failed_registration option.

use OmniAuth::Builder do
  provider :identity,
    :fields => [:email],
    :on_failed_registration => UsersController.action(:new)
end

For more information on rack endpoints, check out this
introduction
and
ActionController::Metal

Customizing Locate Conditions

You can customize the way that matching records are found when authenticating.
For example, for a site with multiple domains, you may wish to scope the search
within a particular subdomain. To do so, add :locate_conditions to your config.
The default value is:

:locate_conditions => lambda {, req, { model.auth_key => req['auth_key']} }

locate_conditions takes a Proc object, and must return a hash. The resulting hash is used
as a parameter in the locate method for your ORM. The proc is evaluated in the
callback context, and has access to the Identity model (using model) and receives the request
object as a parameter. Note that model.auth_key defaults to 'email', but is also configurable.

Note: Be careful when customizing locate_conditions. The best way to modify the conditions is
to copy the default value, and then add to the hash. Removing the default condition will almost
always break things!

License

MIT License. See LICENSE for details.

Copyright

Copyright (c) 2010-2015 Michael Bleigh, and Intridea, Inc.