Keep your value objects from setting into their final output format.
When formatting values in decorator objects we often want to have a default format for their string output, but we also want to access the original values to do arithmetic or other operations. Liquefied lets you have it both ways:
price = Liquefied.new(12.999) { |val| "$%.2f USD" % val }
price.zero? # false
price > 10 # true
price + 1 # 13.999
price.to_s # "$12.99 USD"
puts price # $12.99 USD
The method that invokes the block is a finalizer, which unwraps the liquefied
value to its output format. The default finalizer is to_s, which makes this
pattern helpful for implicit formatting in templates, so <%= price %>
outputs the formatted value.
The finalizer can be set to any other method you want.
Casting to the same type as the original will unwrap the original object:
count = Liquefied.new(1234) { "1,234" }
count.to_i # 1234
ActiveSupport extends core Ruby classes with a format option on to_s, which
enables a simplified usage pattern instead of specifying a block:
require 'active_support/core_ext'
date = Date.new(2016, 1, 1)
date.to_s # "2016-01-01"
date.to_s(:long) # "January 1, 2016"
date = Liquefied.new(date, :long)
date.to_s # "January 1, 2016"
date.to_s(:short) # "Jan 1, 2016"
Add this line to your application's Gemfile:
gem 'liquefied'And then execute:
$ bundle
Or install it yourself as:
$ gem install liquefied
Bug reports and pull requests are welcome on GitHub at https://github.com/avit/liquefied.
The gem is available as open source under the terms of the MIT License.