# OmniAuth Identity
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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.
## Compatibility
This gem is compatible with, as of Feb 2021, version 3:
* Latest released version of omniauth, v2.0.2
* Ruby 2.4, 2.5, 2.6, 2.7, 3.0, ruby-head
## Installation
To acquire the latest release from RubyGems add the following to your `Gemfile`:
```ruby
gem 'omniauth-identity'
```
If the git repository has new commits not yet in an official release, simply specify the repo instead:
```ruby
gem 'omniauth-identity', git: 'https://github.com/intridea/omniauth-identity.git'
```
## Usage
This can be a bit hard to understand the first time. Luckily, Ryan Bates made
a [Railscast](http://railscasts.com/episodes/304-omniauth-identity) about it!
You use `omniauth-identity` just like you would any other OmniAuth provider: as a
Rack middleware. In rails, this would be created by an initializer, such as
`config/initializers/omniauth.rb`. The basic setup for a email/password authentication would look something like this:
```ruby
use OmniAuth::Builder do
provider :identity, #mandatory: tells OA that the Identity strategy is being used
model: Identity, # optional: specifies the name of the "Identity" model. Defaults to "Identity"
fields: %i[email custom1 custom2] # optional: list of custom fields that are in the model's table
end
```
Next, you need to create a model (called `Identity` by default, or specified
with `:model` argument above) 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.
```ruby
class Identity < OmniAuth::Identity::Models::ActiveRecord
auth_key :email # optional: specifies the field within the model that will be used during the login process
# defaults to email, but may be username, uid, login, etc.
# Anything else you want!
end
```
### Mongoid
Include the `OmniAuth::Identity::Models::Mongoid` mixin and specify
fields that you will need.
```ruby
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
Unfortunately MongoMapper is **not supported** in `omniauth-identity` from >= v2.0 as a result of it
not being maintained for several years.
It wasn't possible to include Mongoid *and* MongoMapper due to incompatible gem version
requirements. Therefore precedence was given to Mongoid as it is significantly more
popular and actively maintained.
### DataMapper
Include the `OmniAuth::Identity::Models::DataMapper` mixin and specify
fields that you will need.
```ruby
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.
```ruby
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.
```ruby
use OmniAuth::Builder do
provider :identity, fields: [:email], model: MyCustomClass
end
```
NOTE: In the above example, `MyCustomClass` must have a class method called `auth_key` that returns
the default (`email`) or custom `auth_key` to use.
## 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.
```erb
<%= form_tag '/auth/identity/register' do |f| %>
Create an Account
<%= 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](https://github.com/plataformatec/simple_form), then you
can avoid the params nesting by specifying `:input_html`.
```erb
<%= simple_form_for @identity, :url => '/auth/identity/register' do |f| %>
Create an Account
<%# 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'} %>
<% 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.
```ruby
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](http://library.edgecase.com/Rails/2011/01/04/rails-routing-and-rack-endpoints.html)
and
[ActionController::Metal](http://rubydoc.info/docs/rails/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:
```ruby
use OmniAuth::Builder do
provider :identity,
locate_conditions: ->(req) { { model.auth_key => req['auth_key'] } }
# ...
end
```
`locate_conditions` takes a `Proc` object, and must return a `Hash` object, which will be used
as the argument to the locate method for your ORM. The proc is evaluated in the
callback context, and has access to your `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) 2021 OmniAuth-Identity Maintainers
Copyright (c) 2020 Peter Boling, Andrew Roberts, and Jellybooks Ltd.
Copyright (c) 2010-2015 Michael Bleigh, and Intridea, Inc.