Receiving array in POST in Rails API

Question

I'm creating a Rails API, and I'm trying to receive an array through a post request. On POSTMAN, my request is:

{
    "user": {
        "email": "testuser2@gmail.com",
        "first_name": "Joao Paulo",
        "last_name": "Furtado Silva",
        "city_id": 384,
        "province_id": 2,
        "cuisines": [17,5,2],
        "password":"123456",
        "password_confirmation":"123456"
    }
}

On the user model:

validates :first_name, :last_name, :city_id, :province_id, :cuisines, :password, :password_confirmation, :presence => true

And on User_controller:

def user_params
  params.require(:user).permit(:email, :first_name, :last_name, :city_id, :province_id, :password, :password_confirmation, :cuisines)
end

Even if I pass my cuisines array to the backend, Rails doesn't recognize it. It says as API response:

{
  "status": "Error",
  "message": [
    "Cuisines can't be blank"
  ]
}

What I'm doing wrong here?

If I remove :cuisines from validation, it works fine. But I'm not supposed to do this. What's the best way to solve this issue?

SOLUTION SO FAR:

I removed :cuisines automatic validation from Rails, and validated it manually in a simple code like:

#validate cuisines
@cuisines = params.require(:user)[:cuisines] #it comes in array format

if @cuisines.empty?
  render json: {
    status: 'Error',
    message: 'User cuisines are empty',
  }, status: :precondition_failed

  return false
end

If someone has a better solution, please post.

try to send it with `"cuisines[]": [17,5,2],` . let me know if it is working or not — Vishal, May 22 '18 at 04:35
Still the same error: { "status": "Error", "message": [ "Cuisines can't be blank" ] } — Dr. Joao Paulo, May 22 '18 at 04:41
I added my answer , please check it and let me know if it working or not — Vishal, May 22 '18 at 05:16

score 2 · Answer 1 · answered May 22 '18 at 04:39

2

To declare that the value in params must be an array of permitted scalar values map the key to an empty array:

def user_params
  params.require(:user).permit(:email, :first_name, :last_name, 
  :city_id, :province_id, :password, :password_confirmation, :cuisines => [])
end

You can see the answer with more details here how to permit an array with strong parameters

answered May 22 '18 at 04:39

Andres23Ramirez

647
1
4
14

Ok, this works fine IF I remove the :cuisines from my validates part on User model – Dr. Joao Paulo May 22 '18 at 04:43
validates :first_name, :last_name,:city_id, :province_id, :password,:password_confirmation, :presence => true – Dr. Joao Paulo May 22 '18 at 04:43

score 1 · Answer 2 · answered May 22 '18 at 05:16

If you are using POSTMAN then try to send it with form-data Please check below image

and in your permit method please add cuisines as array

 params.require(:user).permit(:email, :first_name, :last_name, 
  :city_id, :province_id, :password, :password_confirmation, :cuisines => [])

Receiving array in POST in Rails API

2 Answers2