Ruby on Rails - Creating many models associated with another one

Question

So I have the following models:

class Poll < ApplicationRecord
 validates :title, presence: true, allow_blank: false
 validates :options, presence: true
 has_many :options, dependent: :destroy
end
class Option < ApplicationRecord
 validates :title, presence: true, allow_blank: false
 belongs_to :poll
end

And given the following data:

{
 title: "My poll",
 options: [
 {title: "Option 1"},
 {title: "Option 2"},
 {title: "Option 3"},
 ]
}

I would like to create a poll with 3 options.

This is my solution:

 # POST /polls
 def create
 @poll = Poll.new(poll_params)
 params[:options].each do |option|
 @poll.options.new option.permit(:title)
 end
 if @poll.save
 render json: @poll, status: :created, location: @poll
 else
 render json: @poll.errors.full_messages, status: :unprocessable_entity
 end
 end

Answer 1

You should be able to do this with accepts_nested_attributes_for. see https://api.rubyonrails.org/classes/ActiveRecord/NestedAttributes/ClassMethods.html#method-i-accepts_nested_attributes_for

class Poll < ApplicationRecord
 validates :title, presence: true, allow_blank: false
 validates :options, presence: true
 has_many :options, dependent: :destroy
 accepts_nested_attributes_for :options 
end
def poll_params
 params.require(:poll).permit(:title,
 options: :title)
end 
def create
 @poll = Poll.new(poll_params)
 if @poll.save
 render json: @poll, status: :created, location: @poll
 else
 render json: @poll.errors.full_messages, status: :unprocessable_entity
 end
end 

• Enrique Moreno Tent: It works, with a small catch. The parameter must be called options_attributes, instead of options The strong params must be: params.require(:poll).permit(:title, options_attributes: :title)