How to Build a Web App with and without Rails Libraries

mirth-6.rb

# Rack Response: 
# Use Rack::Response instead of returning 
# the response array manually

require 'yaml/store'
require 'rack'
require 'rack/handler/puma'

app = -> environment {
  request = Rack::Request.new(environment)
  
  # Create a Rack::Request object to use
  response = Rack::Response.new

  store = YAML::Store.new("mirth.yml")

  if request.get? && request.path == "/show/birthdays"
    response.write("<ul>\n")
    response.content_type = "text/html; charset=UTF-8"

    all_birthdays =  {}
    store.transaction do
      all_birthdays = store[:birthdays]
    end

    all_birthdays.each do |birthday|
      response.write "<li> #{birthday[:name]}</b> was born on #{birthday[:date]}!</li>\n"
    end
    response.write "</ul>\n"
    response.write <<~STR
        <form action="/add/birthday" method="post" enctype="application/x-www-form-urlencoded">
        <p><label>Name <input type="text" name="name"></label></p>
        <p><label>Birthday <input type="date" name="date"></label></p>
        <p><button>Submit birthday</button></p>
      </form>
    STR

  elsif request.post? && request.path == "/add/birthday"
    new_birthday = request.params.transform_keys(&:to_sym)
    store.transaction do
      store[:birthdays] << new_birthday
    end

    # Redirect response 
    response.redirect('/show/birthdays', 303)
  else
    response.content_type = "text/plain; charset=UTF-8"
    response.write("✅ Received a #{request.request_method} request to #{request.path}!")
  end

  # Mark the response as finish
  response.finish
}

Rack::Handler::Puma.run(app, :Port => 1337, :Verbose => true)

mirth.yml

---
:birthdays:
- :name: Gma
  :date: 01/01/2021
- :name: Tom
  :date: 02/01/2021
- :name: Sesame
  :date: 03/01/2021