Association doesn't save between 2 models - ruby-on-rails

Question

Using Rails 5, I have an issue when I try to save my association between these 2 models : User and Provider
My models :
class User < ApplicationRecord
# Relations
has_and_belongs_to_many :providers
end
class Provider < ApplicationRecord
# Relations
has_and_belongs_to_many :users
accepts_nested_attributes_for :users
end
the Controller :
class ProvidersController < ApplicationController
def new
#provider = current_user.providers.new
end
def create
#provider = current_user.providers.new(provider_params)
if #provider.save
redirect_to root_path
else
render :new
end
end
private
def provider_params
params[:provider][:status] = 'name'
params.require(:provider).permit(:name, :status)
end
Form :
= simple_form_for #provider do |f|
= f.error_notification
= f.input :name, required: false
= f.button :submit
On the create action, a new provider is created but it is not linked to the current user. (no data is insterted in the join table)
I have no idea why I have this behavior.
In console, if i do something like :
#user = User.create(email: "user#test.com", password: "password")
#provider = #user.providers.create(name: "Provider1", status: "name")
#provider.save
then the association is correctly saved.
> #user.providers
=> #<ActiveRecord::Associations::CollectionProxy [#<Provider id: 17, name: "Provider1", status: "name", created_at: "2017-07-25 09:37:19", updated_at: "2017-07-25 09:37:19">]>
Thanks for any idea !
For info, my schema :
create_table "providers", force: :cascade do |t|
t.string "name"
t.string "status"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
create_table "providers_users", id: false, force: :cascade do |t|
t.bigint "provider_id", null: false
t.bigint "user_id", null: false
t.index ["provider_id", "user_id"], name: "index_providers_users_on_provider_id_and_user_id"
t.index ["user_id", "provider_id"], name: "index_providers_users_on_user_id_and_provider_id"
end
create_table "users", force: :cascade do |t|
t.string "email", default: "", null: false
t.string "encrypted_password", default: "", null: false
t.string "reset_password_token"
t.datetime "reset_password_sent_at"
t.datetime "remember_created_at"
t.integer "sign_in_count", default: 0, null: false
t.datetime "current_sign_in_at"
t.datetime "last_sign_in_at"
t.inet "current_sign_in_ip"
t.inet "last_sign_in_ip"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.index ["email"], name: "index_users_on_email", unique: true
t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true
end
Here is the log
ÈStarted POST "/providers" for 127.0.0.1 at 2017-07-25 11:49:27 +0200
Processing by ProvidersController#create as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"27O2Tz4bbqhfRmcuq+0DIZMebSaYVc6IO/uy889Z48fF1l3c8GfIZ+WcQvZKfUeEIB5+YbrM9dON2RH47p3TIQ==", "provider"=>{"name"=>"My new provider"}, "commit"=>"Sauvegarder"}
User Load (0.4ms) SELECT "users".* FROM "users" WHERE "users"."id" = $1 ORDER BY "users"."id" ASC LIMIT $2 [["id", 5], ["LIMIT", 1]]
(0.2ms) BEGIN
SQL (0.4ms) INSERT INTO "providers" ("name", "status", "created_at", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "id" [["name", "My new provider"], ["status", "name"], ["created_at", "2017-07-25 09:49:27.837165"], ["updated_at", "2017-07-25 09:49:27.837165"]]
(4.0ms) COMMIT
Redirected to http://localhost:3000/providers/18/steps.location
Completed 302 Found in 12ms (ActiveRecord: 5.0ms)
Started GET "/providers/18/steps.location" for 127.0.0.1 at 2017-07-25 11:49:27 +0200
Processing by Providers::StepsController#index as
Parameters: {"provider_id"=>"18"}
Redirected to http://localhost:3000/providers/18/steps/registration
Completed 302 Found in 2ms (ActiveRecord: 0.0ms)
Started GET "/providers/18/steps/registration" for 127.0.0.1 at 2017-07-25 11:49:27 +0200
Processing by Providers::StepsController#show as HTML
Parameters: {"provider_id"=>"18", "id"=>"registration"}
Provider Load (0.3ms) SELECT "providers".* FROM "providers" WHERE "providers"."id" = $1 LIMIT $2 [["id", 18], ["LIMIT", 1]]
Rendering providers/steps/registration.html.haml within layouts/provider
User Load (0.3ms) SELECT "users".* FROM "users" INNER JOIN "providers_users" ON "users"."id" = "providers_users"."user_id" WHERE "providers_users"."provider_id" = $1 [["provider_id", 18]]
Rendered providers/steps/registration.html.haml within layouts/provider (13.2ms)
Rendered shared/_head.html.haml (30.6ms) [cache miss]
User Load (0.5ms) SELECT "users".* FROM "users" WHERE "users"."id" = $1 ORDER BY "users"."id" ASC LIMIT $2 [["id", 5], ["LIMIT", 1]]
Rendered shared/_header.html.haml (9.7ms) [cache miss]
Completed 200 OK in 69ms (Views: 64.7ms | ActiveRecord: 1.1ms)

Answer 1

I know maybe it is not the best solution but it is the fastest that comes to my mind
def create
#provider = current_user.providers.create(provider_params)
if #provider.id
redirect_to root_path
else
render :new
end
end
This will create join table record when you use new only why that will work in case of belongs to if provider belongs to user and has user_id in migration current_user.providers.new will add user_id in the new instance, in case has and belongs to many you can do it like this, maybe there is better way but this is what came up to me first.
or something like this
def create
#provider = Provider.new(provider_params)
if #provider.save
current_user.providers << #provider
redirect_to root_path
else
render :new
end
end
one more line but I guess looks cleaner.

Answer 2

def create
#provider = current_user.providers.new(provider_params)
#provider.users = [current_user]
if #provider.save
redirect_to root_path
else
render :new
end
end
I suggest using a has_many through relationship instead of has_many_and_belongs_to, because you can query the join table, and possibly add some more columns in the future in this join table, should the need arise.
P.S. This feels like a Rails bug / feature improvement to me. #provider.users = [current_user] should not be needed anymore as #provider = current_user.providers.new(provider_params) can already be inferred that the #provider object is associated already with current_user, and thus should be automatically assigned already. This already works with has_many though. Seems that only here in HABTM that it does not automatically assign.