app/views/admin/users/_add_role.html.erb
<div id="<%= role_class_name.downcase %>_role">
<h3><%= role_class_name %></h3>
<div class='text-center'>
<%= form_tag [:grant_user_role_admin,@user], remote: true, data: {success: "#role_list"}, class: 'form-inline remote-form' do -%>
<label for="role_authorizable_name"><%= role_class_name %> role</label>
<%= select "role", "authorizable_name", @all_roles, { prompt: true }, {class: 'form-control'} %>
<label for="role_authorizable_id">for <%= role_class_name %></label>
<%= select "role", "authorizable_id", authorizable_type.pluck(:name,:id), { prompt: true }, {class: 'form-control'} %>
<%= hidden_field_tag 'role[authorizable_type]', role_class_name %>
<%= submit_tag "Add #{role_class_name} role", class: 'btn btn-success' %>
<% end -%>
</div>
</div>