Paginate an existing resultset

Sometimes you have a resultset that you can’t use with the built-in Rails pagination tool. This code below will fix the issue for you.

  # Place this in application.rb

  # Paginate an existing resultset.
  # Example:
  #   @pages, @users = paginate_collection User.find_custom_query, :page => @params[:page]
  
  def paginate_collection(collection, options = {})
    default_options = {:per_page => 10, :page => 1}
    options = default_options.merge options
    
    pages = Paginator.new self, collection.size, options[:per_page], options[:page]
    first = pages.current.offset
    last = [first + options[:per_page], collection.size].min
    slice = collection[first...last]
    return [pages, slice]
  end