Existence is a simple Ruby library that exposes Active Support's present? and blank? methods to the following classes:

• Array
• FalseClass
• Hash
• NilClass
• String
• TrueClass

It is intended to provide these helper methods to projects that do not include ActiveSupport. It is tested against the latest patch release for each minor version of Ruby 2.

In your Gemfile, include the existence gem and then bundle install.

gem 'existence'

The same patterns used in ActiveSupport can be expected with Existence.

• An array is present if it has elements, and blank if it does not.

  [].present? # => false
  [].blank? # => true
  ['test'].present? # => true
  ['test'].blank? # => false

• false is never present and always blank.

  false.present? # => false
  false.blank? # => true

• A hash is present if it contains values, and blank if it does not.

  {}.present? # => false
  {}.blank? # => true
  { test: true }.present? # => true
  { test: true }.blank? # => false

• nil is never present and always blank.

  nil.present? # => false
  nil.blank? # => true

• A string is present if it contains non-whitespace characters, and blank if it does not.

  ''.present? # => false
  ''.blank? # => true
  'test'.present? # => true
  'test'.blank? # => false

• true is always present and never blank.

  true.present? # => true
  true.blank? # => false