Make long pre-reqs/learning objectives expandable. Fixes #1096

Author: fbacall

app/helpers/materials_helper.rb

@@ -101,7 +101,7 @@ def display_difficulty_level(resource)
     end
   end
 
-  def display_attribute(resource, attribute, show_label: true, title: nil, markdown: false, list: false)
+  def display_attribute(resource, attribute, show_label: true, title: nil, markdown: false, list: false, expandable: false)
     return if [
       TeSS::Config.feature['disabled'].include?(attribute.to_s),
       (TeSS::Config.feature['materials_disabled'].include?(attribute.to_s) && resource.is_a?(Material)),
@@ -120,6 +120,9 @@ def display_attribute(resource, attribute, show_label: true, title: nil, markdow
           string << "<li>#{block_given? ? yield(v) : v}</li>"
         end
         string << '</ul>'
+      elsif expandable
+        height_limit = expandable.is_a?(Numeric) ? expandable : nil
+        string << "<div class=\"tess-expandable\"#{" data-height-limit=\"#{height_limit}\"" if height_limit}>" + value.to_s + '</div>'
       else
         string << value.to_s
       end

app/views/common/_extra_metadata.html.erb

@@ -68,8 +68,8 @@
 <% if resource.is_a?(LearningPath) %>
   <%= display_attribute(resource, :status) { |value| material_status_title_for_label(value) } %>
   <%= display_attribute(resource, :target_audience) { |values| values.map { |x| target_audience_title_for_label(x) }.join(', ') } %>
-  <%= display_attribute(resource, :prerequisites, markdown: true) %>
-  <%= display_attribute(resource, :learning_objectives, markdown: true) %>
+  <%= display_attribute(resource, :prerequisites, markdown: true, expandable: 150) %>
+  <%= display_attribute(resource, :learning_objectives, markdown: true, expandable: 150) %>
 <% end %>
 
 <% if resource.respond_to?(:operations) -%>