app/views/catalog/_embedded_mirador3.html.erb
<% if document.manifest_url.present? %>
<% manifest_url = document.manifest_url.starts_with?('/') ? root_url + document.manifest_url.slice(1..-1) : document.manifest_url %>
<%= content_tag :iframe, '',
src: "#{Settings.iiif_embed.url}?#{{ url: manifest_url }.to_query}",
allowfullscreen: true,
class: 'mirador-embed-wrapper',
frameborder: 0,
marginwidth: 0,
marginheight: 0,
scrolling: 'no',
width: '100%'
%>
<%= iiif_drag_n_drop(manifest_url) %>
<% end %>