using scopes on ransack search and sort

gistfile1.rb

#paste this code in your ransack.rb initializer
#if you want to use scopes on search or sort please use Class.ransack_with_scopes instead of Class.search
Ransack::Adapters::ActiveRecord::Base.class_eval do
	def ransack(params = {}, options = {}, scope_used_on_sort = false)
		Ransack::Search.new(self, params, options, scope_used_on_sort)
	end
	def ransack_with_scopes(params = {}, options = {})
		scope_used_on_sort = false
		ransack_scope = self
		ransack_params = {}
		(params||{}).each_pair do |k,v|
			if ransack_scope.respond_to?(k)
				ransack_scope = (v == true) ? ransack_scope.send(k) : (ransack_scope.method(k.to_sym).arity <= 0 ? ransack_scope.send(k) : ransack_scope.send(k, v))
			else
				#maybe its a s parameter for sorting
				scope_name = "sort_by_" + v.to_s.gsub(" ", "_")
				if ransack_scope.respond_to?(scope_name)
					ransack_scope = ransack_scope.send(scope_name)
					scope_used_on_sort = true
				end
				ransack_params.merge!(k => v)
			end
		end 
		ransack_scope.ransack(ransack_params, options, scope_used_on_sort)
	end
end

Ransack::Search.class_eval do
	def initialize(object, params = {}, options = {}, scope_used_on_sort = false)
		@scope_used_on_sort = scope_used_on_sort
		(params ||= {}).delete_if { |k, v| v.blank? && v != false }
		@context = Ransack::Context.for(object, options)
		@context.auth_object = options[:auth_object]
		@base = Ransack::Nodes::Grouping.new(@context, 'and')
		build(params.with_indifferent_access)
	end
	def scope_used_on_sort?
		@scope_used_on_sort
	end
end

Ransack::Adapters::ActiveRecord::Context.class_eval do
	def evaluate(search, opts = {})
		viz = Ransack::Visitor.new
		relation = @object.where(viz.accept(search.base))
		if search.sorts.any? && !search.scope_used_on_sort?
			relation = relation.except(:order).reorder(viz.accept(search.sorts))
		end
		opts[:distinct] ? relation.select("DISTINCT #{@klass.quoted_table_name}.*") : relation
	end
end

Thanks for this patch it is ok for my project!