Draper CollectionDecorator and pagination with kaminari

I’m working with kaminari today, and I spent a bit of time getting Draper to co-operate with the pagination. This is a fairly well documented issue, but I figured I’d post about this for my own future reference.

The issue: getting kaminari methods (such as current_page, total_pages, etc) to work on a decorated collection.

The solution: We need to delegate the kaminari methods, so that Draper knows to ignore them.

How to do this?

1. Create a separate PaginatingDecorator that inherits from CollectionDraper, and delegate the kaminari methods.

	class PaginatingDecorator < Draper::CollectionDecorator
	delegate :current_page, :total_pages, :limit_value
	end

view raw paginating_decorator.rb hosted with ❤ by GitHub

1. In your ApplicationDecorator class, make sure that CollectionDecorator knows to look at PaginatingDecorator.

	class ApplicationDecorator < Draper::Decorator
	def self.collection_decorator_class
	PaginatingDecorator
	end
	end

view raw application_decorator.rb hosted with ❤ by GitHub

1. If it’s not already the case, make sure your decorator inherits from ApplicationDecorator

	class AnimalDecorator < ApplicationDecorator
	decorates :animal
	delegate_all
	...
	end

view raw animal_decorator.rb hosted with ❤ by GitHub