app/views/notifications/index.html.erb
<h1 style="font-size: 2rem">Your notifications</h1>
<% @notifications.each do |notification| %>
<%= link_to notification, class: 'black-text text-lighten-3' do %>
<div class="hoverable card <%= 'blue lighten-5' unless notification.viewed_at? %>">
<div class="card-content">
<div class="card-title">
<i class="material-icons left <%= notification.icon_color %>-text"><%= notification.icon %></i>
<%= notification.message_html.html_safe %>
</div>
<div>
<small class="grey-text"><%= time_ago_in_words notification.happened_at %> ago</small>
</div>
</div>
</div>
<% end %>
<% end %>
<% if @notifications.empty? %>
<div class="card-panel">
Notifications will appear here whenever you receive any. You'll also be able to view them directly from the bell dropdown at the top of the page.
</div>
<% end %>