scinote-web/app/views/shared/navigation/_breadcrumbs.html.erb

<% if @breadcrumbs_items&.length %>
  <% shortened = @breadcrumbs_items.length > 4 %>

  <% if shortened %>
    <% first_breadcrumb_item = @breadcrumbs_items.shift
      last_breadcrumb_items = @breadcrumbs_items.pop(2) %>
    <%= link_to(first_breadcrumb_item[:label], first_breadcrumb_item[:url],
                  class: "breadcrumbs-link #{first_breadcrumb_item[:class]}",
                  title: first_breadcrumb_item[:label],
                  data: first_breadcrumb_item[:data]) %>
    <span class="delimiter">&gt;</span>
    <span class="breadcrumbs-collapsed-container">
        <span class="show-breadcrumbs" data-toggle="dropdown" title="<%= t('projects.index.breadcrumbs_collapsed') %>">
          •••
          <span class="caret pull-right"></span>
        </span>
        <ul class="dropdown-menu breadcrumbs-dropdown" role="menu">
          <% @breadcrumbs_items.each do |item| %>
            <li>
              <%= link_to(item[:label] + ' >', item[:url],
                          data: item[:data]) %>
            </li>
          <% end %>
        </ul>
    </span>
    <span class="delimiter">&gt;</span>
    <% item = last_breadcrumb_items.first %>
    <%= link_to(item[:label], item[:url],
                class: "breadcrumbs-link #{item[:class]}",
                title: item[:label],
                data: item[:data]) %>
    <span class="delimiter">&gt;</span>
    <% last_item = last_breadcrumb_items.last %>
    <span class="breadcrumbs-link <%= last_item[:class] %>" title="<%= last_item[:label] %>">
      <%= last_item[:label] %>
    </span>
  <% else %>
    <% last_item = @breadcrumbs_items.pop %>
    <% @breadcrumbs_items.each do |item| %>
      <%= link_to(item[:label], item[:url],
                  class: "breadcrumbs-link #{item[:class]}",
                  title: item[:label],
                  data: item[:data]) %>
      <span class="delimiter">&gt;</span>

    <% end %>
    <span class="breadcrumbs-link <%= last_item[:class] %>" title="<%= last_item[:label] %>">
      <%= last_item[:label] %>
    </span>
  <% end %>
<% end %>