Rails ActiveModel :: Serializers中的JSON API样式侧载

Question

I'm trying to build a JSON API style API using AM::Serializer. I'm running into an issue with sideloading.

I want to be able to build JSON that looks like:

{
    "primaries": [{
        "id": 123,
        "data": "Hello world.",
        "links": {
            "secondaries": [ 1, 2, 3 ]
        }
    }],
    "linked" : {
        "secondaries": [
            {
                "id": 1,
                "data": "test1"
            },
            {
                "id": 2,
                "data": "test2"
            },
            {
                "id": 3,
                "data": "test3"
            }
        ]
    }
}

The code I've been able to come up with looks like:

class PrimarySerializer < ActiveModel::Serializer
  attributes :id, :data

  has_many :secondaries, key: :secondaries, root: :secondaries
  embed :ids, include: true
end

Which generates JSON that looks like:

{
    "primaries": [{
        "id": 123,
        "data": "Hello world.",
        "secondaries": [ 1, 2, 3 ]
    }],
    "secondaries": [
        {
            "id": 1,
            "data": "test1"
        },
        {
            "id": 2,
            "data": "test2"
        },
        {
            "id": 3,
            "data": "test3"
        }
    ]
}

Is there a way to override the location of the in-element secondaries and sideloaded secondaries such that they live in child nodes link and linked ?

The above code is an abstraction of the actual code and may not work. Hopefully it illustrates the point sufficiently.

Thanks!

Answer 1

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