songkick/oauth2-provider

<h3>Sign in</h3>

<p>Who are you? We&rsquo;d ask for a password usually, but seeing as it&rsquo;s
  <em>you</em>&hellip;</p>

<form method="post" action="/login">
  <% @oauth2.params.each do |key, value| %>
    <input type="hidden" name="<%= key %>" value="<%= value %>">
  <% end %>

  <fieldset>
    <label for="username">Username</label>
    <input type="text" name="username" id="username">
  </fieldset>

  <fieldset>
    <input type="submit" value="Sign in">
  </fieldset>
</form>