ActiveModel Serializers can do this. The problem is that the built-in association methods are to restrictive. Instead you must build up the links
& linked
parts manually.
(This answer refers to the stable 0.8.1 version of ActiveModel Serializers)
Here's a Gist with a complete JSON-API solution https://gist.github.com/mars/97a637560109b8ddfb27
Example:
class ExampleSerializer < JsonApiSerializer # see Gist for superclass
attributes :id, :name, :links
def links
{
things: object.things.map(&:id),
whatzits: object.whatzits.map(&:id)
}
end
def as_json(*args)
hash = super(*args)
hash[:linked] = {
things: ActiveModel::ArraySerializer.new(
object.things,
each_serializer: ThingsSerializer
).as_json,
whatzits: ActiveModel::ArraySerializer.new(
object.whatzits,
each_serializer: WhatzitsSerializer
).as_json
}
hash
end
end