Unitize

Unitize is gem for Rails inspired by the marvelous Unitwise gem, with the only expection that all measurement units are saved on your database. Do you have a weird non-linear measurement unit conversion that you want to add to your collection at runtime? With Unitize you can!

Compatibility

This gem has been tested only on postgresql. sqlite won't work for now as remarked in issue #1.

Usage

# Create a measurement type:
m_type = Unitize::MeasurementType.create({name: "length"})

# Create a foundamental measurement unit: 
f_unit = Unitize::MeasurementUnit.create({
	name: "meter", 
	measurement_type: m_type, 
	code: "m", 
	symbol: "m"
})

# Create a measurement prefix:
prefix = Unitize::MeasurementPrefix.create({
	name: "centi", 
	symbol: "c", 
	code: "c", 
	scalar: "0.01"
})

# Create a derived measurement unit (note that is not derived from the meter, m, but from the centimeter, cm):
d_unit = Unitize::MeasurementUnit.create({
	name: "inch", 
	measurement_type: m_type, 
	code: "in", 
	symbol: "inch", 
	scale_value: "2.539998", 
	scale_unit_code: "cm"
})

# Create a weird special measurement unit:
my_weird_unit = Unitize::MeasurementUnit.create({
	name: "weird length from meter", 
	measurement_type: m_type, 
	code: "wl", 
	symbol: "wl", 
	scale_value: "1", 
	scale_unit_code: "m", 
	scale_function_from: "100+x/2", 		# this should be the inverse function of scale_function_to
	scale_function_to: "2*x-200", 			# this should be the inverse function of scale_function_from
	special: true
})

# It's time to use it:
meter = Unitize(12, "m")
to_centimeter = meter.to("cm")
to_inch = meter.to("in")
to_weird_unit = meter.to("wl")

puts meter.to_s(:name)                   # => 12 meter
puts to_centimeter.to_s(:name)           # => 1200 centimeter
puts inch.to_s(:name)                    # => 39.37 inch
puts to_weird_unit.to_s(:name)           # => -176 weird length from meter
puts to_weird_unit.to("m").to_s(:name)   # => 12 meter

All other functionalities have been copied from Unitwise gem. Check it out: https://github.com/joshwlewis/unitwise

Installation

Add this line to your application's Gemfile:

# add the gem to your Gemfile
gem 'unitize', git: 'https://github.com/pinkynrg/Unitize.git'

# bundle it
bundle install

# install the gem
rails g unitize:install

# migrate new tables
rails db:migrate

# if you want import 300+ measurement units from UCUM list execute this command too:
rake unitize:import

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

License

The gem is available as open source under the terms of the MIT License.