undefined method `will_paginate', Rails 3.1 / DataMapper

Question

Newly installed will_paginate 3.0.0

gem \'will_paginate\', \'~> 3.0.0\', :require=>\'will_paginate/data_mapper\'

Running a controller que

Answer 1

There is a similar question with an answer that indicates that auto-requiring here is the problem. See will_paginate undefined method. The Will_paginate gem appears to work though for the question and answer.

Answer 2

gem 'will_paginate', '~> 3.0.0', require: %w[
  will_paginate
  will_paginate/data_mapper
]

Answer 3

Don't use the :require option in the Gemfile, as you already figured out; instead require "will_paginate/data_mapper" somewhere in config/application.rb, for instance after the Bundler setup.