Attribute Boolean

The purpose of this gem is to provide an attr_boolean shortcut to classes. This shortcut creates accessors that, when assigned to with a variety of "falsey" or "truthy" data, can be interpreted as intended.

Installation

Add this line to your application's Gemfile:

gem 'attribute_boolean'

And then execute:

$ bundle

Or install it yourself as:

$ gem install attribute_boolean

Usage

In a standard Ruby class, you might have something like this:

class Calculation

  include AttributeBoolean

  attr_boolean :complete

end

This provides you with the "#{attr}=" and "#{attr}?" methods:

c = Calculation.new

c.complete = "1"
c.complete? #=> true

c.complete = "0"
c.complete? #=> false

c.complete = "yes"
c.complete? #=> true

c.complete = "no"
c.complete? #=> false

The default values that are interpreted as false is:

[ false, 0, '0', 'f', 'F', 'false', 'FALSE', 'off', 'OFF', 'n', 'N', 'no', 'NO' ]

This can be customized globally like this:

AttributeBoolean.false_values = [ "dunno", -1, :negative ]
AttributeBoolean.false_values += [ "no way", 0 ]

Or the false_values list can be set individually per attr_boolean call. Using this option will replace the global list for that attribute.

attr_boolean :complete, false_values: [ 'it is not complete', 'not completed', :nope ]
attr_boolean :in_progress, false_values: Set.new(:no, 'nope')

Specify a default value for the attribute that will be used if it (1) hasn't been set, or (2) has been set to nil. The value passed to default is casted to a boolean using !!default.

attr_boolean :complete, default: true

AttributeBoolean converts all symbols to strings when evaluating truthiness:

obj.complete = :no
obj.complete? #=> false

obj.complete = :yes
obj.complete? #=> true

Rails

If Rails is loaded when this gem loads, it will automatically inject the AttributeBoolean module into ActiveRecord::Base, preventing the need to call include AttributeBoolean on ActiveRecord classes.

Contributing

1. Fork it ( https://github.com/[my-github-username]/attribute_boolean/fork )
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 a new Pull Request