komagata/app.rb

## app.rb
require "sinatra"
require_relative "memo"

Memo.data_dir = "memos"

get "/" do
  @memos = Memo.all
  erb :index, layout: :layout
end

get "/new" do
  erb :new, layout: :layout
end

get "/:id" do
  @memo = Memo.find(params[:id])
  erb :show, layout: :layout
end

get "/:id/edit" do
  @memo = Memo.find(params[:id])
  erb :edit, layout: :layout
end

post "/" do
  @memo = Memo.new
  @memo.body = params[:body]
  @memo.create
  redirect "/"
end

patch "/:id" do
  @memo = Memo.find(params[:id])
  @memo.body = params[:body]
  @memo.save
  redirect "/#{params[:id]}"
end

delete "/:id" do
  @memo = Memo.find(params[:id])
  @memo.destroy
  redirect "/"
end

helpers do
  def nl2br(text)
    text.gsub("\n", "<br>")
  end
end

## edit.erb
<form action="/<%= @memo.id %>" method="post">
  <input type="hidden" name="_method" value="patch">
  <textarea name="body" cols="60" rows="20"><%= @memo.body %></textarea>
  <p><input type="submit" value="変更"></p>
</form>

## index.erb
<ul>
  <% @memos.each do |memo| %>
    <li>
      <a href="<%= memo.id %>"><%= memo.title %></a>
    </li>
  <% end %>
</ul>

<p><a href="/new">追加</a></p>

## layout.erb
<!DOCTYPE html>
<html lang="ja">
  <head>
    <meta charset="utf-8">
    <title>メモアプリ</title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" media="all" href="" />
  </head>
  </body>
    <h1><a href="/">メモアプリ</a></h1>
    <%= yield %>
  </body>
</html>

## memo.rb
require "pathname"
require "securerandom"

class Memo
  attr_accessor :id, :title, :body, :created_at, :updated_at

  def self.data_dir=(data_dir)
    @@data_dir = data_dir
  end

  def self.data_dir
    @@data_dir
  end

  def self.new_from_path(path)
    memo = Memo.new
    File.open(path) do |f|
      memo.id = File.basename(f, ".txt")
      memo.body = f.read
      memo.created_at = f.birthtime
      memo.updated_at = f.mtime
    end

    memo
  end

  def self.find(id)
    self.new_from_path("#{self.data_dir}/#{id}.txt")
  end

  def self.all
    Pathname.glob("#{self.data_dir}/*.txt").map do |f|
      self.new_from_path(f)
    end
  end

  def self.titles
    self.all.map(&:title)
  end

  def create
    @id = generate_id
    save
  end

  def save
    File.open("#{@@data_dir}/#{@id}.txt", "w") do |f|
      f.write @body
    end
  end

  def destroy
    File.delete "#{@@data_dir}/#{@id}.txt"
  end

  def generate_id
    titles = Memo.titles
    id = SecureRandom.urlsafe_base64
    while titles.include?(id) do
      id = SecureRandom.urlsafe_base64
    end
    id
  end

  def title
    @body.chomp.split("\n")&.first || "タイトルなし"
  end
end

## new.erb
<form action="/" method="post">
  <textarea name="body" cols="60" rows="20"></textarea>
  <p><input type="submit" value="追加"></p>
</form>

## show.erb
<%= nl2br(@memo.body) %>

<p><a href="/<%= @memo.id %>/edit">変更</a></p>

<p>
  <form action="/<%= @memo.id %>" method="post">
    <input type="hidden" name="_method" value="delete">
    <input type="submit" value="削除">
  </form>
</p>
	require "sinatra"
	require_relative "memo"

	Memo.data_dir = "memos"

	get "/" do
	@memos = Memo.all
	erb :index, layout: :layout
	end

	get "/new" do
	erb :new, layout: :layout
	end

	get "/:id" do
	@memo = Memo.find(params[:id])
	erb :show, layout: :layout
	end

	get "/:id/edit" do
	@memo = Memo.find(params[:id])
	erb :edit, layout: :layout
	end

	post "/" do
	@memo = Memo.new
	@memo.body = params[:body]
	@memo.create
	redirect "/"
	end

	patch "/:id" do
	@memo = Memo.find(params[:id])
	@memo.body = params[:body]
	@memo.save
	redirect "/#{params[:id]}"
	end

	delete "/:id" do
	@memo = Memo.find(params[:id])
	@memo.destroy
	redirect "/"
	end

	helpers do
	def nl2br(text)
	text.gsub("\n", "<br>")
	end
	end
	<form action="/<%= @memo.id %>" method="post">
	<input type="hidden" name="_method" value="patch">
	<textarea name="body" cols="60" rows="20"><%= @memo.body %></textarea>
	<p><input type="submit" value="変更"></p>
	</form>
	<ul>
	<% @memos.each do \|memo\| %>
	<li>
	<a href="<%= memo.id %>"><%= memo.title %></a>
	</li>
	<% end %>
	</ul>

	<p><a href="/new">追加</a></p>
	<!DOCTYPE html>
	<html lang="ja">
	<head>
	<meta charset="utf-8">
	<title>メモアプリ</title>
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<link rel="stylesheet" media="all" href="" />
	</head>
	</body>
	<h1><a href="/">メモアプリ</a></h1>
	<%= yield %>
	</body>
	</html>
	require "pathname"
	require "securerandom"

	class Memo
	attr_accessor :id, :title, :body, :created_at, :updated_at

	def self.data_dir=(data_dir)
	@@data_dir = data_dir
	end

	def self.data_dir
	@@data_dir
	end

	def self.new_from_path(path)
	memo = Memo.new
	File.open(path) do \|f\|
	memo.id = File.basename(f, ".txt")
	memo.body = f.read
	memo.created_at = f.birthtime
	memo.updated_at = f.mtime
	end

	memo
	end

	def self.find(id)
	self.new_from_path("#{self.data_dir}/#{id}.txt")
	end

	def self.all
	Pathname.glob("#{self.data_dir}/*.txt").map do \|f\|
	self.new_from_path(f)
	end
	end

	def self.titles
	self.all.map(&:title)
	end

	def create
	@id = generate_id
	save
	end

	def save
	File.open("#{@@data_dir}/#{@id}.txt", "w") do \|f\|
	f.write @body
	end
	end

	def destroy
	File.delete "#{@@data_dir}/#{@id}.txt"
	end

	def generate_id
	titles = Memo.titles
	id = SecureRandom.urlsafe_base64
	while titles.include?(id) do
	id = SecureRandom.urlsafe_base64
	end
	id
	end

	def title
	@body.chomp.split("\n")&.first \|\| "タイトルなし"
	end
	end
	<form action="/" method="post">
	<textarea name="body" cols="60" rows="20"></textarea>
	<p><input type="submit" value="追加"></p>
	</form>
	<%= nl2br(@memo.body) %>

	<p><a href="/<%= @memo.id %>/edit">変更</a></p>

	<p>
	<form action="/<%= @memo.id %>" method="post">
	<input type="hidden" name="_method" value="delete">
	<input type="submit" value="削除">
	</form>
	</p>