Rails STI and strong parameters

Question

I have a Client resource with 2 types: Person and Company.

routes.rb:

resources :clients
resources :people, :controller => "clients", :type => "Person"
resources :companies, :controller => "clients", :type => "Company"

clients_controller:

def new
  @client = Client.new()
  @client.type = params[:type]
end

def create
  @client = current_partner.clients.new(client_params)
  if @client.save
    redirect_to clients_path
  ...
end

...
private
def client_params
  params.require(:client).permit(:type, :partner_id, :name, :email, :phone, :cui,   :registration_id, :address)
end

def find_client
  @client ||= Client.find(params[:id])
end

client.rb

class Client < ActiveRecord::Base
  validates_presence_of :type
  CLIENT_TYPES = ['Person', 'Company']
end

person.rb

class Person < Client
  validates_presence_of :name, :email, :phone
end

compay.rb

class Company < Client
  validates_presence_of :name, :email, :cui, :registration_id, :phone
  validates_uniqueness_of :cui, :registration_id, uniqueness: {scope: :partner_id}
end

The problem is when I'm trying to edit a client's details and I submit the changes, I get param is missing or the value is empty: client. The route from where I'm getting this error is .../companies/3.

Any help on this noobie question? Thanks!

Answer 1

You can disguise your inherited model to it's parent before the permit action by

def client_params

  if params.has_key? :person
    params[:client] = params.delete :person
  elsif params.has_key? :company
    params[:client] = params.delete :company
  end

  params.require(:client).permit(...)

end

Its just renaming the model's key in the params hash, and does the trick.

Answer 2

Models

I think you're not using STI's properly

STI's are for Models, not controllers. As per the MVC programming pattern, your Models handle all the data-construction methodology. Your controllers are used as an interim between your user inputs & your views:

This means that if you want to use or create STI-driven functionality, you'll be best just using the backend classes for it (instead of manually passing type etc):

#app/models/person.rb
Class Person < Client
   ...
end

#app/models/company.rb
Class Company < Client
end

#app/models/client.rb
Class Client < ActiveRecord::Base
end

This will give you the ability to do this:

#config/routes.rb
resources :clients
resources :people,    controller: "clients", type: "Person"
resources :companies, controller: "clients", type: "Company"

#app/controllers/clients_controller.rb
Class ClientsController < ApplicationController
    def create
       model = get_model(params[:type])

       @model = model.new(model_params)
       @model.save
    end

    private

    def get_model type
       return type.singularize.titleize.camelize.constantize
    end

    def model_params
        params.require(params[:type].to_sym).permit(:client, :model, :attributes)
    end
end

This will the various STI Model that you've set by accessing /people or /companies, and then give you the ability to save data to it (which will save to the Client model with type set, of course)