ruby on rails - Returning count of child in json.rabl -

i have location model render in json format using rabl. index.json.rabl looks way :

object false collection @locations  attributes :id, :name, :address, :rating 

:rating integer calculated records in rating model (a location has_many rating, rating belongs_to location). retrieve in rabl file number of line of rating model used calculate value.

i tried :

child :ratings     attributes :count end 

and

node(:ratings_count) { |m| @ratings.count } 

but doesn't work... me there ?

thanks !

if don't misunderstand mean. think want use rating.count in rabl.

you have closed answer using "node".

node(:ratings_count) { |l| l.ratings.count }  

in block of node, local variable "l" 1 object of collection above.