app/views/admin/attributes.html.erb
<div class="row">
<div class="col s12">
<h1>Attributes</h1>
</div>
</div>
<div class="row">
<div class="col s4">
<h2>Attributes per user</h1>
<%= column_chart User.joins(:attribute_fields).group(:user_id).count().group_by { |n| n.last }.each_with_object({}) { |(content_count, ids), h| h[content_count] = ids.count } %>
</div>
<%# TODO: attributes per each content type %>
<div class="col s4">
<h2>Attribute privacy</h1>
<%= pie_chart AttributeField.where.not(privacy: "").group(:privacy).count() %>
</div>
</div>