trustieforge/app/views/messages/show.html.erb

<% if @project %>
    <%= render :partial => 'project_show', locals: {project: @project} %>
<% elsif @course %>
    <%= render :partial => 'course_show', locals: {course: @course} %>
<% else %>
    <%= render :partial => 'org_subfield_show', :locals => {:org_subfield => @org_subfield} %>
<% end %>