How to Build a Web App with and without Rails Libraries

mirth-7.rb

# Persistent storage with SQLite: 
# Use SQLite to store data instead
# of YAML

require 'rack'
require 'rack/handler/puma'

# Require the sqlite3 gem
require 'sqlite3'

app = -> environment {
  request = Rack::Request.new(environment)
  response = Rack::Response.new

  # Create a SQLite3 Database Object
  database = SQLite3::Database.new("mirth.sqlite3", results_as_hash: true)

  if request.get? && request.path == "/show/birthdays"
    response.write("<ul>\n")
    response.content_type = "text/html; charset=UTF-8"
    
    # Get all birthdays from the database
    all_birthdays = database.execute("SELECT * FROM birthdays")

    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

    # Create a query to add the new data
    query = "INSERT INTO birthdays (name, date) VALUES (?, ?)"
    database.execute(query, [new_birthday['name'], new_birthday['date']])
    
    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

  response.finish
}

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