Rails: Unpermitted parameter in Rails 5 - ruby-on-rails

Question

First of all I want simply get an object inside the current object that I'm sending to my backend.
I have this simple JSON (generated from a form):
{
"name": "Project 1",
"project_criteria": [
{
"name": "Criterium 1",
"type": "Type 1",
"benefit": "1"
},
{
"name": "Criterium 2",
"type": "Type 2",
"benefit": "3"
}
]
}
My classes:
class Project < ApplicationRecord
has_many :project_criteria
accepts_nested_attributes_for :project_criteria
end
class ProjectCriterium < ApplicationRecord
belongs_to :project
end
ProjectsController:
def project_params
params.require(:project).permit(:name, project_criteria: [] )
end
But I still can't access project_criteria parameter as you can see below:
Started POST "/projects" for 127.0.0.1 at 2016-08-19 16:24:03 -0300
Processing by ProjectsController#create as HTML
Parameters: {"project"=>{"name"=>"Project 1", "project_criteria"=>{"0"=>{"benefit"=>"1", "name"=>"Criterium 1", "type"=>"Type 1"}, "1"=>{"benefit"=>"3", "name"=>"Criterium 2", "type"=>"Type 2"}}}}
Unpermitted parameter: project_criteria # <-----------
Note:
By the way, I already tried to use criterium instead of criteria(which - in my opinion - is the correct since it should be pluralized) in has_many and accepts_nested_attributes_for, but it also doesn't work.
Does someone have a solution for this?

Answer 1

It's not the inflection of the word "criteria" that's giving you problems (although you can add a custom inflector to get the singular and plural versions you prefer if you really want).
The issue is that you have to explicitly permit the fields of nested objects.
Change your current params:
params.require(:project).permit(:name, project_criteria: [] )
To this (for a single nested object):
params.require(:project).permit(:name, project_criteria: [:name, :type, :benefit] )
Your case is somewhat compounded by the fact that you're dealing with multiple nested objects, so you'll have to pass a hash instead:
params.require(:project).permit(:name, { project_criteria: [:name, :type, :benefit]} )

Answer 2

I had this issue when working on a Rails 6 application.
My application consists of a User model that has a one-to-one relationship a Personal_Info model
My original code was this:
User Model
class User < ApplicationRecord
has_one :personal_info, class_name: 'PersonalInfo', dependent: :destroy
accepts_nested_attributes_for :personal_info, allow_destroy: true
end
Personal Info Model
class PersonalInfo < ApplicationRecord
belongs_to :user
end
User Controller
class UsersController < ApplicationController
def index
#users = User.all
end
.
.
def user_params
params.require(:user).permit(:email, :password, :password_confirmation,
personal_info_attributes: [:first_name,
:last_name, :phone, :gender, :dob,
:address, :city, :state, :country])
end
end
The issue was that I did not add the Personal_Info id to the accepted user params (parameters).
Here's how I fixed it:
I simply had to add the Personal_Info id to the UsersController params this way:
User Controller
class UsersController < ApplicationController
def index
#users = User.all
end
.
.
def user_params
params.require(:user).permit(:email, :password, :password_confirmation,
personal_info_attributes: [:id, :first_name,
:last_name, :phone, :gender, :dob,
:address, :city, :state, :country])
end
end
Another way is to add the update_only option to the Users Model this way:
class User < ApplicationRecord
has_one :personal_info, class_name: 'PersonalInfo', dependent: :destroy
accepts_nested_attributes_for :personal_info, update_only: true, allow_destroy: true
end
That's all.
I hope this helps