JamesACM JamesAndresCM

The Complete Guide to Nested Forms in Phoenix

I recently spent some time dealing with nested forms in Phoenix. Nested forms are great when you want to create multiple database records in a single transaction and associate them with each other. I am new to Phoenix and really struggled to find any resources that helped me with my specific problem. I decided to document what I learned in the process in hopes of helping others that are new to Elixir and Phoenix.

Here is my attempt at a one stop shop to learn everything you will need to know about nested forms. If you would like to view the GitHub repo you can check it out here.

Thanks to Heartbeat and Jose for excellent blog posts on nested forms. Also shoutout to Josh for showing me some examples at Ruby

Estos serian los perfiles?, que en realidad el modelo es group

Customer.first.groups

  Customer Load (1.3ms)  SELECT  "customers".* FROM "customers" WHERE "customers"."deleted_at" IS NULL ORDER BY "customers"."id" ASC LIMIT $1  [["LIMIT", 1]]
  Group Load (1.4ms)  SELECT  "groups".* FROM "groups" WHERE "groups"."deleted_at" IS NULL AND "groups"."customer_id" = $1 LIMIT $2  [["customer_id", 1], ["LIMIT", 11]]
=> #<ActiveRecord::Associations::CollectionProxy [#<Group id: 3, name: "Admin", created_at: "2023-03-23 19:29:42", updated_at: "2023-03-23 19:29:42", customer_id: 1, deleted_at: nil, local_id: "71877852-23aa-43fa-8ed0-ea46ed4b76e2", threshold_quantity: nil>, #<Group id: 13, name: "prueba", created_at: "2023-06-07 22:08:25", updated_at: "2023-06-07 22:08:25", customer_id: 1, deleted_at: nil, local_id: "b4f5e733-2571-49c8-a8bb-3352085c410a", threshold_quantity: nil>]>

JWT Auth + Refresh Tokens in Rails

This is just some code I recently used in my development application in order to add token-based authentication for my api-only rails app. The api-client was to be consumed by a mobile application, so I needed an authentication solution that would keep the user logged in indefinetly and the only way to do this was either using refresh tokens or sliding sessions.

I also needed a way to both blacklist and whitelist tokens based on a unique identifier (jti)

Before trying it out DIY, I considered using:

Install ntfs-3g

brew tap gromgit/homebrew-fuse
brew install --cask macfuse
brew install ntfs-3g-mac

Enable Security development in your mac (startup boot configuration -> utilities)

Identify your ntfs HDD

Async Proccess Elixir

run_query = fn query_def -> Process.sleep(2000); "#{query_def} result" end
async_query = fn query_def -> spawn(fn -> IO.puts(run_query.(query_def)) end) end
Enum.each(1..5, &async_query.("query #{&1}"))

	# Elixir + Phoenix Framework 1.3 + Guardian + JWT(Refresh, Revoke, Recover) + Comeonin

	### User model bootstrap
	Let's generate User model and controller.

	```bash
	mix ecto.create # create DB table
	mix phx.gen.json Accounts User users email:string password_hash:string # scaffold users structure
	```

	# first way
	# frozen_string_literal: true

	class EncryptionService
	delegate :encrypt_and_sign, :decrypt_and_verify, to: :encryptor

	class << self
	def encrypt(secret:)
	new.encrypt_and_sign(secret)
	end

	module Utilities
	def self.included(base)
	base.extend(ClassMethods)
	end

	def method_one
	puts 'Hello from an instance method'
	end

	module ClassMethods

	# categories without link
	rails g model Category name parent_id:integer:index

	class Category < ApplicationRecord
	has_many :subcategories, class_name: 'Category', foreign_key: 'parent_id', dependent: :destroy
	belongs_to :parent, class_name: 'Category', foreign_key: 'parent_id', optional: true
	end

	# linked_categories
	rails g model Category name

	class ReviewConfiguration < BaseRecord
	has_many :review_answers, dependent: :destroy
	accepts_nested_attributes_for :review_answers, allow_destroy: true
	end

	def review_answers_attributes=(attributes)
	attributes = attributes.map(&:deep_symbolize_keys)
	review_answer_ids = attributes.map{\|el\| el[:id]}.compact
	begin
	review_answers << ReviewAnswer.where(id: review_answer_ids)