Implements the HasFilters controller concern

app/controllers/concerns/has_filters.rb

@@ -0,0 +1,13 @@
+module HasFilters
+  extend ActiveSupport::Concern
+
+  class_methods do
+    def has_filters(valid_filters, *args)
+      before_filter(*args) do
+        @valid_filters = valid_filters
+        @current_filter = params[:filter]
+        @current_filter = @valid_filters.first unless @valid_filters.include?(@current_filter)
+      end
+    end
+  end
+end