Rake task to export default settings as seeds

db/seeds/templates/units.erb

@@ -0,0 +1,9 @@
+Unit.transaction do
+  Unit.defaults.delete_all
+<% Unit.defaults.ordered.each do |unit| %>
+<%= "\n" if unit.base.nil? %>
+  unit_<%= unit.symbol %> =
+    Unit.create symbol: "<%= unit.symbol %>",<% unless unit.base.nil? %> base: unit_<%= unit.base.symbol %>, multiplier: <%= unit.multiplier.to_scientific %>,<% end %>
+                description: "<%= unit.description %>"
+<% end %>
+end

db/seeds/units.rb

@@ -0,0 +1,36 @@
+Unit.transaction do
+  Unit.defaults.delete_all
+
+  unit_1 =
+    Unit.create symbol: "1",
+                description: "dimensionless, one"
+  unit_ppm =
+    Unit.create symbol: "ppm", base: unit_1, multiplier: 1e-6,
+                description: "parts per million"
+  unit_‱ =
+    Unit.create symbol: "‱", base: unit_1, multiplier: 1e-4,
+                description: "basis point"
+  unit_‰ =
+    Unit.create symbol: "‰", base: unit_1, multiplier: 1e-3,
+                description: "promille"
+  unit_% =
+    Unit.create symbol: "%", base: unit_1, multiplier: 1e-2,
+                description: "percent"
+
+  unit_g =
+    Unit.create symbol: "g",
+                description: "gram"
+  unit_ug =
+    Unit.create symbol: "ug", base: unit_g, multiplier: 1e-6,
+                description: "microgram"
+  unit_mg =
+    Unit.create symbol: "mg", base: unit_g, multiplier: 1e-3,
+                description: "milligram"
+  unit_kg =
+    Unit.create symbol: "kg", base: unit_g, multiplier: 1e3,
+                description: "kilogram"
+
+  unit_kcal =
+    Unit.create symbol: "kcal",
+                description: "kilocalorie"
+end