Deserializing Json-Api with Rails Strong Parameters - active-model-serializers

Question

I am using Active Model Serializers 0.10.x with EmberCLI and Rails while trying to have the Json-Api as the Adapter. GET requests are working, but deserialization for the Active Model is not even though I tried to implement the rails strong_parameters solution described by jimbeaudoin here.
My latest attempt in saving a comment:
Payload:
{"data":{
"attributes": {"soft_delete":false,"soft_delete_date":null,"text":"hjfgfhjghjg","hidden":false,"empathy_level":0},
"relationships":{
"user":{"data":{"type":"users","id":"1"}},
"post":{"data":{"type":"posts","id":"1"}}},"type":"comments"}}
Console Output:
Completed 400 Bad Request in 13ms (ActiveRecord: 8.6ms)
ActionController::ParameterMissing (param is missing or the value is empty: data):
Comments Controller:
class Api::V1::CommentsController < MasterApiController
respond_to :json
...
def create
render json: Comment.create(comment_params)
end
...
def comment_params
#Deserialization issues... Waiting for #950 https://github.com/rails-api/active_model_serializers/pull/950
params.require(:data).require(:attributes).permit(:text, :user_id, :post_id, :empathy_level, :soft_delete_date, :soft_delete, :hidden)
end
end
Noting that if I set the parameters to only params.permit(...), the server saves it with everything null (I did not set any constraints on the comments model for now):
data: {id: "9", type: "comments",…}
attributes: {soft_delete: null, soft_delete_date: null, text: null, hidden: null, empathy_level: null}
id: "9"
relationships: {post: {data: null}, user: {data: null}}
type: "comments"
You can access the full code here.

Answer 1

Update #2: For AMS >= 0.10.2, please check other answers.
Update #1: Answer is still valid for AMS 0.10.1.
If you use 0.10.0.rc4, you can now use the Deserialization implementation described on Active Model Serializers #1248.
def post_params
ActiveModel::Serializer::Adapter::JsonApi::Deserialization.parse(params.to_h)
// or (params.to_unsafe_h) in some cases like in my example below...
end
Bonus: If you use Ember Data, then you can see an example implementation on my Fakktion Github repo.

Answer 2

For AMS >= 0.10.2
In 0.10.2 there was a cleanup so after 0.10.2 use:
def post_params
ActiveModelSerializers::Deserialization.jsonapi_parse(params)
end
Reference:
https://github.com/rails-api/active_model_serializers/commit/252f9c4ae932e6280dfe68605d495b208fe22ba7

Answer 3

With AMS 0.10.2+
Use only hash to create a parameter whitelist,
def post_params
ActiveModelSerializers::Deserialization.jsonapi_parse!(
params, only: [:title, :author, :tags]
)
end

Answer 4

For googlers:
If you have empty data payload, you need to add Mime support
https://stackoverflow.com/a/32013294/2664779
When you want to access json-api formatted json, you should do it like this
(in your controller)
def create
user = User.new(user_params)
...
end
private
def user_params
params.require(:data).require(:attributes).permit(:email, :password)
end
When previously I would do it like this
private
def user_params
params.require(:user).permit(:email, :password)
end