This version of will_paginate is optimized for Rails 5 on Ruby 2.2+ and compatibility with the Ransack search gem:

• Strings are now frozen to be immutable, to reduce object allocations and memory use.
• Rails 5 composes ActionController::Parameters as a HWIA instead of inheriting from Hash. Ransack needs nested options hashes in AC::Parameters to be parsed correctly. This is handled here.
• Legacy code for Rails 2 and 3 and Merb was removed to make the gem more lightweight.

Installation:

gem 'will_paginate', github: 'jonatack/will_paginate'

In the controller:

  # perform a paginated query
  @posts = Post.paginate(page: params[:page])

  # use an explicit "per page" limit
  Post.paginate(page: params[:page], per_page: 30)

  # will_paginate returns a chainable Active Record relation
  Post.where(published: true).paginate(page: params[:page]).order(id: :desc)

  # the new, shorter #page method
  Post.page(params[:page]).order(created_at: :asc)

In the view, to render pagination links:

  <%= will_paginate @posts %>

And that's it! You just need to add some CSS styles to make those pagination links prettier.

You can customize the default "per_page" value:

  # for the Post model
  class Post
    self.per_page = 10
  end

  # set per_page globally
  WillPaginate.per_page = 10

Happy paginating! ❤️