Feature-flag debates

app/controllers/concerns/feature_flags.rb

@@ -0,0 +1,25 @@
+module FeatureFlags
+  extend ActiveSupport::Concern
+
+  class_methods do
+    def feature_flag(name, *options)
+      before_filter(*options) do
+        check_feature_flag(name)
+      end
+    end
+  end
+
+  def check_feature_flag(name)
+    raise FeatureDisabled, name unless Setting["feature.#{name}"]
+  end
+
+  class FeatureDisabled < Exception
+    def initialize(name)
+      @name = name
+    end
+
+    def message
+      "Feature disabled: #{@name}"
+    end
+  end
+end