1 files changed, 85 insertions, 0 deletions
diff --git a/app/controllers/concerns/sorting_preference.rb b/app/controllers/concerns/sorting_preference.rb
new file mode 100644
index 00000000000..a51b68147d5
--- /dev/null
+++ b/app/controllers/concerns/sorting_preference.rb
@@ -0,0 +1,85 @@
+# frozen_string_literal: true
+
+module SortingPreference
+  include SortingHelper
+  include CookiesHelper
+
+  def set_sort_order
+    set_sort_order_from_user_preference || set_sort_order_from_cookie || params[:sort] || default_sort_order
+  end
+
+  # Implement sorting_field method on controllers
+  # to choose which column to store the sorting parameter.
+  def sorting_field
+    nil
+  end
+
+  # Implement default_sort_order method on controllers
+  # to choose which default sort should be applied if
+  # sort param is not provided.
+  def default_sort_order
+    nil
+  end
+
+  # Implement legacy_sort_cookie_name method on controllers
+  # to set sort from cookie for backwards compatibility.
+  def legacy_sort_cookie_name
+    nil
+  end
+
+  private
+
+  def set_sort_order_from_user_preference
+    return unless current_user
+    return unless sorting_field
+
+    user_preference = current_user.user_preference
+
+    sort_param = params[:sort]
+    sort_param ||= user_preference[sorting_field]
+
+    return sort_param if Gitlab::Database.read_only?
+
+    if user_preference[sorting_field] != sort_param
+      user_preference.update(sorting_field => sort_param)
+    end
+
+    sort_param
+  end
+
+  def set_sort_order_from_cookie
+    return unless legacy_sort_cookie_name
+
+    sort_param = params[:sort] if params[:sort].present?
+    # fallback to legacy cookie value for backward compatibility
+    sort_param ||= cookies[legacy_sort_cookie_name]
+    sort_param ||= cookies[remember_sorting_key]
+
+    sort_value = update_cookie_value(sort_param)
+    set_secure_cookie(remember_sorting_key, sort_value)
+    sort_value
+  end
+
+  # Convert sorting_field to legacy cookie name for backwards compatibility
+  # :merge_requests_sort => 'mergerequest_sort'
+  # :issues_sort => 'issue_sort'
+  def remember_sorting_key
+    @remember_sorting_key ||= sorting_field
+      .to_s
+      .split('_')[0..-2]
+      .map(&:singularize)
+      .join('')
+      .concat('_sort')
+  end
+
+  # Update old values to the actual ones.
+  def update_cookie_value(value)
+    case value
+    when 'id_asc'             then sort_value_oldest_created
+    when 'id_desc'            then sort_value_recently_created
+    when 'downvotes_asc'      then sort_value_popularity
+    when 'downvotes_desc'     then sort_value_popularity
+    else value
+    end
+  end
+end