CRUD method for a model that belongs_to many models Rails - ruby-on-rails

Question

I'm new to Rails and I might be missing something very basic here:
User can create contact for both branches and division of a company
Branch.rb
class Branch < ApplicationRecord
belongs_to :company
has_many :contacts
end
Division.rb
class Division < ApplicationRecord
belongs_to :company
has_many :contacts
end
Contact.rb
class Contact < ApplicationRecord
belongs_to :branch
belongs_to :division
end
Now a user can create a contact from the branch page where there is no division_id and can create a contact from the Division page.
I have defined my routes.rb like this:
Routes.rb
resources :companies, :shallow => true do
get 'company_page'
resources :branches, :shallow => true do
get 'branch_page'
resources :contacts
end
resources :divisions, :shallow => true do
get 'division_page'
resources :contacts
end
end
As a result, if I create a contact from either Branch or Division, it goes to contacts#create method.
In my contacts_controller.rb, I have:
def create
#newContact = Contact.new(contact_params)
id = #division = #branch = nil
isBranch = false
if params[:branch_id] != nil
isBranch = true
id = params[:branch_id]
else
isBranch = false
id = params[:division_id]
end
if isBranch
branch = Branch.find(id)
#newContact.branch = branch
#branch = branch
else
division = Division.find(id)
#newContact.division = division
#division = division
end
respond_to do |format|
if #newContact.save
format.js
format.html { render :nothing => true, :notice => 'Contact created successfully!' }
format.json { render json: #newContact, status: :created, location: #newContact }
else
format.html { render action: "new" }
format.json { render json: #newContact, status: :unprocessable_entity }
end
end
end
But I have facing ActiveRecord Error during #newContact.save.
I'm sure I am doing something fundamentally very wrong here and Rails handles such things in another elegant way which I don't know of.

Answer 1

As #Anthony noted, you'll need to make your belongs_to associations optional:
# app/models/contact.rb
class Contact < ApplicationRecord
belongs_to :branch, optional: true
belongs_to :division, optional: true
end
But another problem is that params[:division_id] and params[:branch_id] are always nil. Both of those keys exist inside the [:contact] key. So the error you are getting should be ActiveRecord::RecordNotFound: Couldn't find Division with 'id'=
All that conditional logic is unnecessary. You can just make a new contact with whatever params are given. Also, you should be using Ruby convention for variable naming, which is snake_case instead of camelCase.
Finally, I assume you'll want to redirect HTML requests to either the branch or the division show page, depending on which was associated. So I've added logic to do that.
Here's a quick refactoring of the controller #create action:
def create
#new_contact = Contact.new(contact_params)
if #new_contact.save
branch = #new_contact.branch
division = #new_contact.division
redirect_path = branch ? branch_path(branch) : division_path(division)
respond_to do |format|
format.js
format.html { redirect_to redirect_path, :notice => 'Contact created successfully!' }
format.json { render json: #new_contact, status: :created, location: #new_contact }
end
else
respond_to do |format|
format.html { render action: "new" }
format.json { render json: #new_contact, status: :unprocessable_entity }
end
end
end
This proves that it works:
# spec/controllers/contacts_controller_spec.rb
require 'rails_helper'
RSpec.describe ContactsController, type: :controller do
let(:company) { Company.create!(name: 'Company Name') }
let(:division) { Division.create!(name: 'Division Name', company: company) }
let(:branch) { Branch.create!(name: 'Branch Name', company: company) }
describe '#create' do
context 'when created with a division id' do
let(:attributes) { {'division_id' => division.id, 'name' => 'Contact Name'} }
it 'creates a contact record and associates it with the division' do
expect(Contact.count).to eq(0)
post :create, params: {contact: attributes}
expect(Contact.count).to eq(1)
contact = Contact.first
expect(contact.division).to eq(division)
end
end
context 'when created with a branch id' do
let(:attributes) { {'branch_id' => branch.id, 'name' => 'Contact Name'} }
it 'creates a contact record and associates it with the branch' do
expect(Contact.count).to eq(0)
post :create, params: {contact: attributes}
expect(Contact.count).to eq(1)
contact = Contact.first
expect(contact.branch).to eq(branch)
end
end
end
end