Class: ActiveNutrition::Utilities::UnitConverter

Inherits:
Object
  • Object
show all
Defined in:
lib/active_nutrition/utilities/unit_converter.rb

Constant Summary collapse

CONVERSIONS = 
{
  :oz =>     { :lb => 16.0 },  # i.e. to convert from pounds to ounces, multiply by 16 (because there are 16 ounces per pound)
  :lb =>     { :oz => 1.0/16.0 },
  :tsp =>    { :tbsp => 3.0,      :cup  => 48.0,      :pint => 96.0,    :quart => 192.0,  :gallon => 768.0 },
  :tbsp =>   { :tsp => 1.0/3.0,   :cup  => 16.0,      :pint => 32.0,    :quart => 64.0,   :gallon => 256.0 },
  :cup =>    { :tsp => 1.0/48.0,  :tbsp => 1.0/16.0,  :pint => 2.0,     :quart => 4.0,    :gallon => 16.0 },
  :pint =>   { :tsp => 1.0/96.0,  :tbsp => 1.0/32.0,  :cup => 1.0/2.0,  :quart => 2.0,    :gallon => 8.0 },
  :quart =>  { :tsp => 1.0/192.0, :tbsp => 1.0/64.0,  :cup => 1.0/4.0,  :pint => 1.0/2.0, :gallon => 4.0 },
  :gallon => { :tsp => 1.0/768.0, :tbsp => 1.0/256.0, :cup => 1.0/16.0, :pint => 1.0/8.0, :quart => 1.0/4.0 }
}

Class Method Summary collapse

Class Method Details

.convert(value, options = {}) ⇒ Object 



18
19
20
21
22
23
24
 
# File 'lib/active_nutrition/utilities/unit_converter.rb', line 18

def convert(value, options = {})
  unless supported_conversion?(options)
    raise "Conversion not supported - are you trying to convert weight to volume?"
  end

  value * CONVERSIONS[options[:to]][options[:from]]
end

.supported_conversion?(options = {}) ⇒ Boolean

Returns:

  • (Boolean) 


26
27
28
 
# File 'lib/active_nutrition/utilities/unit_converter.rb', line 26

def supported_conversion?(options = {})
  CONVERSIONS.include?(options[:to]) && CONVERSIONS[options[:to]].include?(options[:from])
end