How to deserialize parameters with relationships using ActiveModelSerializers?

Question

I used to code below to deserialize the JSON API data send from client,

def action_record_params
  ActiveModelSerializers::Deserialization.jsonapi_parse!(params)
end

When I pass the following data from the client, the deserializer cannot see relationships attributes.

Client send parameter

params = {"data": {"type": "action_record", "attributes": {"value": ""}}, "relationships": {"card": {"data": {"type": "card", "id": "#{card.id}"}}}}

Server deserialized data

{:value=>""}

How to deserialize parameters with relationships using ActiveModelSerializers?

Answer 1

Base on AMS documentation Deserialization section, which can be found below

https://github.com/rails-api/active_model_serializers/blob/master/docs/general/deserialization.md

The relationships can be extracted by via the option only: [:relatedModelName]. only is act as a whitelist in this case.

Sample Data

document = {
  'data' => {
    'id' => 1,
    'type' => 'post',
    'attributes' => {
      'title' => 'Title 1',
      'date' => '2015-12-20'
    },
    'relationships' => {
      'author' => {
        'data' => {
          'type' => 'user',
          'id' => '2'
        }
      },
      'second_author' => {
        'data' => nil
      },
      'comments' => {
        'data' => [{
          'type' => 'comment',
          'id' => '3'
        },{
          'type' => 'comment',
          'id' => '4'
        }]
      }
    }
  }
}

AMS deserialization with options

ActiveModelSerializers::Deserialization
  .jsonapi_parse(document, only: [:title, :date, :author],
                           keys: { date: :published_at },
                           polymorphic: [:author])

Output hash

# {
#   title: 'Title 1',
#   published_at: '2015-12-20',
#   author_id: '2',
#   author_type: 'user'
# }