This gem provides a simple value object for dealing with measures used in cooking and baking. Behind the scenes it uses unitwise. The main difference in behaviour is support for unitless measures which are often found in recipes, such as "2 eggs" or "1 large carrot".

Add this line to your application's Gemfile:

gem 'kitchen_measures'

And then execute:

$ bundle

Or install it yourself as:

$ gem install kitchen_measures

flour_measure = KitchenMeasures::Measure.with_unit(500, "g")
sugar_measure = KitchenMeasures::Measure.with_unit(2, "oz")
water_measure = KitchenMeasures::Measure.with_unit(1, "l")
eggs_measure = KitchenMeasures::Measure.without_unit(6)

flour_measure.to_s #=> 1000 g
sugar_measure.to_s #=> 2 oz
water_measure.to_s #=> 2 l
eggs_measure.to_s #=> 12

flour_measure.weight? #=> true
flour_measure.volume? #=> false
eggs_measure.weight? #=> false
eggs_measure.volume? #=> false
eggs_measure.volume? #=> false

flour_measure.comparable_with?(sugar_measure) #=> true
flour_measure.comparable_with?(water_measure) #=> false

KitchenMeasures isn't coupled to Rails, but there a couple of methods provided for convenience.

.from_db_attrs accepts a quantity, and an unit. If the unit is nil, the measure will be treated as unitless.

#to_db_attrs does the opposite. It converts a measure to has so that it can be persisted to the database. This will also ensure units are stored in a consistent way, e.g. "kg" instead of "kilogram".

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/andyw8/kitchen_measures.