agenda-libre-ruby/app/views/regions/_selector.haml

%nav.region_selector
  -# Display the currently selected region
  %h3
    - if params[:region]
      = Region.find params[:region]
      %em.fa.fa-chevron-down
    - else
      %span.placeholder
        =t '.all_regions'
        %em.fa.fa-chevron-down

  -# Choose a region to filter events with
  %ul
    %li
      = link_to t('.all_regions'), region: nil,
        start_date: params[:start_date],
        year: params[:year],
        tag: params[:tag]

    - Region.all.each do |region|
      %li
        = link_to region, region: region.id,
          start_date: params[:start_date],
          year: params[:year],
          tag: params[:tag]