Adding Social Login With OmniAuth

Bumbled around a bit with this video because I didn't RTFM as I should have. It's critical to read through everything, as there are quite a few moving pieces you need to set up.

The Routes

The first thing to do is to let Devise know about our omniauth controller. In routes.rb, add this:

 devise_for <span class="hljs-symbol">:users</span>,
    <span class="hljs-symbol">controllers:</span> { 
      <span class="hljs-symbol">sessions:</span> <span class="hljs-string">&quot;users/passwordless&quot;</span>, 
      <span class="hljs-symbol">omniauth_callbacks:</span> <span class="hljs-string">&#x27;users/omniauth_callbacks&#x27;</span>
    }

The Controller

The controller itself is reasonably straightforward, but I redid the forwarding paths:

<span class="hljs-keyword">class</span> <span class="hljs-title class_">Users::OmniauthCallbacksController</span> &lt; <span class="hljs-title class_ inherited__">Devise::OmniauthCallbacksController</span>

  <span class="hljs-keyword">def</span> <span class="hljs-title function_">github</span>
    <span class="hljs-comment"># You need to implement the method below in your model (e.g. app/models/user.rb)</span>
    <span class="hljs-variable">@user</span> = <span class="hljs-title class_">User</span>.from_omniauth(request.env[<span class="hljs-string">&quot;omniauth.auth&quot;</span>])

    <span class="hljs-keyword">if</span> <span class="hljs-variable">@user</span>.persisted?
      sign_in_and_redirect <span class="hljs-variable">@user</span>, <span class="hljs-symbol">event:</span> <span class="hljs-symbol">:authentication</span> <span class="hljs-comment"># this will throw if <span class="hljs-doctag">@user</span> is not activated</span>
      set_flash_message(<span class="hljs-symbol">:notice</span>, <span class="hljs-symbol">:success</span>, <span class="hljs-symbol">kind:</span> <span class="hljs-string">&quot;GitHub&quot;</span>) <span class="hljs-keyword">if</span> is_navigational_format?
    <span class="hljs-keyword">else</span>
      session[<span class="hljs-string">&quot;devise.github_data&quot;</span>] = request.env[<span class="hljs-string">&quot;omniauth.auth&quot;</span>].except(<span class="hljs-symbol">:extra</span>) <span class="hljs-comment"># Removing extra as it can overflow some session stores</span>
      redirect_to new_user_session_url
    <span class="hljs-keyword">end</span>
  <span class="hljs-keyword">end</span>

  <span class="hljs-keyword">def</span> <span class="hljs-title function_">failure</span>
    redirect_to root_path
  <span class="hljs-keyword">end</span>
<span class="hljs-keyword">end</span>

The Model

The User model needs a way to find the user, and it's imperative you don't double up on emails! 

<span class="hljs-keyword">class</span> <span class="hljs-title class_">User</span> &lt; <span class="hljs-title class_ inherited__">ApplicationRecord</span>
  <span class="hljs-comment"># Include default devise modules. Others available are:</span>
  <span class="hljs-comment"># :confirmable, :lockable, :timeoutable, :trackable and :omniauthable</span>
  devise <span class="hljs-symbol">:magic_link_authenticatable</span>, <span class="hljs-symbol">:validatable</span>, <span class="hljs-symbol">:rememberable</span>,
    <span class="hljs-symbol">:omniauthable</span>, <span class="hljs-symbol">omniauth_providers:</span> %i[github]

  <span class="hljs-keyword">def</span> <span class="hljs-title function_">is_admin?</span>
    <span class="hljs-keyword">return</span> <span class="hljs-literal">true</span> <span class="hljs-keyword">if</span> email ==<span class="hljs-string">&quot;robconery@gmail.com&quot;</span>
  <span class="hljs-keyword">end</span>

  <span class="hljs-keyword">def</span> <span class="hljs-title function_">self</span>.from_omniauth(auth)
    user = <span class="hljs-title class_">User</span>.find_by(<span class="hljs-symbol">email:</span> auth.info.email)
    <span class="hljs-keyword">unless</span> user
      user = <span class="hljs-title class_">User</span>.create!(
        <span class="hljs-symbol">email:</span> auth.info.email,
        <span class="hljs-symbol">provider:</span> auth.provider, 
        <span class="hljs-symbol">uid:</span> auth.uid,
        <span class="hljs-symbol">name:</span> auth.info.name
      )
    <span class="hljs-keyword">end</span>
    user
  <span class="hljs-keyword">end</span>

<span class="hljs-keyword">end</span>