A link renderer for WillPaginate that converts your pagination to a hash for rendering in Json

index.json.rabl

object false

child @products => 'products' do
  attributes :name, :description, :id
end

node(:pagination) { will_paginate(@products, :renderer => JsonRenderer) }

JsonRenderer.rb

class JsonRenderer < WillPaginate::ViewHelpers::LinkRendererBase
  
  def prepare(collection, options, context)
    super(collection, options)
    @context = context
  end
  
  def to_json
    {
      :next_page => url(next_page),
      :previous_page => url(previous_page)
    }
  end
  alias :to_html :to_json
  
  private 
    def url(page)
      return nil unless page
      @context.url_for(:page => page, :per_page => @collection.per_page)
    end
  
    def previous_page
      @collection.current_page > 1 && @collection.current_page - 1
    end

    def next_page
      @collection.current_page < @collection.total_pages && @collection.current_page + 1
    end
  
end

class Hash
  def html_safe
    self
  end
end

ProductsController.rb

class ProductsController < ApplicationController
  include WillPaginate::ViewHelpers

  def index
    @products = Product.paginate(:page => params[:page], :per_page => params[:per_page])
    
    render :json => { :products => @products, :pagination => will_paginate(@products, :renderer => JsonRenderer) }
  end
  
end