Add QR Code generation and sharing

Gemfile

@@ -27,6 +27,9 @@ gem "action_policy", "~> 0.7.0"
 # Authentication
 gem "bcrypt", "~> 3.1.20"
 
+# QR code
+gem "rqrcode", "~> 2.0"
+
 # Other
 gem "bootsnap", require: false
 gem "puma", ">= 5.0"

Gemfile.lock

@@ -128,6 +128,7 @@ GEM
       regexp_parser (>= 1.5, < 3.0)
       xpath (~> 3.2)
     childprocess (5.0.0)
+    chunky_png (1.4.0)
     coderay (1.1.3)
     coercible (1.0.0)
       descendants_tracker (~> 0.0.1)
@@ -350,6 +351,10 @@ GEM
     rexml (3.3.1)
       strscan
     rouge (4.3.0)
+    rqrcode (2.2.0)
+      chunky_png (~> 1.0)
+      rqrcode_core (~> 1.0)
+    rqrcode_core (1.2.0)
     rspec (3.13.0)
       rspec-core (~> 3.13.0)
       rspec-expectations (~> 3.13.0)
@@ -522,6 +527,7 @@ DEPENDENCIES
   rack-mini-profiler
   rails (~> 7.1.3, >= 7.1.3.4)
   rails-controller-testing
+  rqrcode (~> 2.0)
   rspec-instafail
   rspec-rails
   rspec-retry

app/controllers/application_controller.rb

@@ -1,3 +1,11 @@
 class ApplicationController < ActionController::Base
   include Authentication
+
+  rescue_from ActiveRecord::RecordNotFound, with: :record_not_found
+
+  private
+
+  def record_not_found
+    render file: Rails.public_path.join("404.html").to_s, status: :not_found, layout: false
+  end
 end

app/controllers/profiles_controller.rb

@@ -0,0 +1,21 @@
+class ProfilesController < ApplicationController
+  before_action :set_profile, only: [:show, :qr_code]
+
+  def show
+  end
+
+  def qr_code
+    send_data(
+      QRCodeGenerator.new(profile_url(@profile.uuid)).as_png(size: 240),
+      filename: "#{@profile.name}.png",
+      type: "image/png",
+      disposition: "attachment"
+    )
+  end
+
+  private
+
+  def set_profile
+    @profile = Profile.public_profiles.find_by!(uuid: params[:uuid])
+  end
+end

app/helpers/profile_helper.rb

@@ -0,0 +1,5 @@
+module ProfileHelper
+  def qr_code_svg(profile)
+    QRCodeGenerator.new(profile_url(profile.uuid)).as_svg(module_size: 4)
+  end
+end

app/javascript/controllers/qr_controller.js

@@ -0,0 +1,25 @@
+import { Controller } from '@hotwired/stimulus'
+
+export default class extends Controller {
+  static targets = ['button']
+
+  async share () {
+    const button = this.buttonTarget
+
+    if (navigator.share) {
+      try {
+        const file = await fetch(button.dataset.url)
+          .then((response) => response.blob())
+          .then((blob) => new File([blob], 'qr.png', { type: 'image/png' }))
+
+        await navigator.share({
+          files: [file], title: 'QR Code'
+        })
+      } catch (err) {
+        window.open(button.dataset.url)
+      }
+    } else {
+      window.open(button.dataset.url)
+    }
+  }
+}

app/lib/qr_code_generator.rb

@@ -0,0 +1,21 @@
+class QRCodeGenerator
+  def initialize(url)
+    @url = url
+  end
+
+  def as_svg(options = {})
+    qr.as_svg(options)
+  end
+
+  def as_png(options = {})
+    qr.as_png(options)
+  end
+
+  private
+
+  attr_reader :url
+
+  def qr
+    @_qr ||= RQRCode::QRCode.new(url)
+  end
+end

app/models/profile.rb

@@ -11,18 +11,32 @@
 #  name             :string
 #  profileable_type :string           not null
 #  twitter_url      :string
+#  uuid             :string
 #  created_at       :datetime         not null
 #  updated_at       :datetime         not null
 #  profileable_id   :integer          not null
 #
 # Indexes
 #
 #  index_profiles_on_profileable  (profileable_type,profileable_id)
+#  index_profiles_on_uuid         (uuid) UNIQUE
 #
 class Profile < ApplicationRecord
   belongs_to :profileable, polymorphic: true
 
   has_one :self_ref, class_name: "Profile", foreign_key: :id, inverse_of: :self_ref, dependent: :destroy
   has_one :user, through: :self_ref, source: :profileable, source_type: "User"
   has_one :speaker, through: :self_ref, source: :profileable, source_type: "Speaker"
+
+  validates :uuid, uniqueness: true
+
+  before_create :set_uuid
+
+  scope :public_profiles, -> { where(is_public: true) }
+
+  private
+
+  def set_uuid
+    self.uuid = SecureRandom.uuid
+  end
 end

app/views/layouts/application.html.erb

@@ -12,7 +12,7 @@
 </head>
 
 <body>
-<main class="container mx-auto mt-28 px-5 flex">
+<main class="container mx-auto mt-28 px-5">
   <div><%= notice %></div>
   <div><%= alert %></div>
   <% if user_signed_in? %>

app/views/profiles/show.html.erb

@@ -0,0 +1,23 @@
+<h1>Profile</h1>
+
+<h2>My QR Code</h2>
+
+<%= render inline: qr_code_svg(@profile) %>
+<br>
+
+<!-- Save QR -->
+<%= link_to 'Save QR Code', qr_code_profile_path(@profile.uuid), method: :get %>
+<br>
+<br>
+
+<!-- Share QR -->
+<div data-controller="qr">
+  <button id="shareQR" data-action="click->qr#share" data-qr-target="button" data-url="<%= qr_code_profile_path(@profile.uuid) %>">
+    Share
+  </button>
+</div>
+<br>
+
+<!-- Open Camera -->
+<h3>Scan a code</h3>
+<input type="file" accept="image/*" capture="capture">

config/environments/development.rb

@@ -79,4 +79,7 @@
 
   # Raise error when a before_action's only/except options reference missing actions
   config.action_controller.raise_on_missing_callback_actions = true
+
+  # Allow ngrok hosts
+  config.hosts << /[a-z0-9.\-]+\.ngrok\.io/
 end

config/initializers/inflections.rb

@@ -11,6 +11,6 @@
 # end
 
 # These inflection rules are supported but not enabled by default:
-# ActiveSupport::Inflector.inflections(:en) do |inflect|
-#   inflect.acronym "RESTful"
-# end
+ActiveSupport::Inflector.inflections(:en) do |inflect|
+  inflect.acronym "QR"
+end

config/routes.rb

@@ -10,4 +10,9 @@
   resource :session, only: [:new, :create, :destroy]
   resource :password, only: [:edit, :update]
   resource :password_reset, only: [:new, :create, :edit, :update]
+  resources :profiles, only: [:show, :edit, :update], param: :uuid do
+    member do
+      get :qr_code
+    end
+  end
 end

db/migrate/20240710213305_add_profile_uuid_to_profile.rb

@@ -0,0 +1,6 @@
+class AddProfileUuidToProfile < ActiveRecord::Migration[7.1]
+  def change
+    add_column :profiles, :uuid, :string
+    add_index :profiles, :uuid, unique: true
+  end
+end

spec/controllers/profiles_controller_spec.rb

@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+RSpec.describe ProfilesController, type: :controller do
+  let(:profile) { create(:profile, :with_user, :public) }
+
+  before do
+    sign_in(profile.user)
+  end
+
+  describe "GET #show" do
+    it "returns a success response" do
+      get :show, params: {uuid: profile.uuid}
+      expect(response).to have_http_status(:success)
+    end
+
+    context "when the profile is not public" do
+      let(:profile) { create(:profile, :with_user, is_public: false) }
+
+      it "returns a not found response" do
+        get :show, params: {uuid: profile.uuid}
+        expect(response).to have_http_status(:not_found)
+      end
+    end
+  end
+
+  describe "GET #qr_code" do
+    it "returns a PNG" do
+      get :qr_code, params: {uuid: profile.uuid}
+      expect(response.headers["Content-Type"]).to eq("image/png")
+      expect(response.headers["Content-Disposition"]).to include("#{profile.name}.png")
+    end
+  end
+end

spec/factories/profiles.rb

@@ -11,13 +11,15 @@
 #  name             :string
 #  profileable_type :string           not null
 #  twitter_url      :string
+#  uuid             :string
 #  created_at       :datetime         not null
 #  updated_at       :datetime         not null
 #  profileable_id   :integer          not null
 #
 # Indexes
 #
 #  index_profiles_on_profileable  (profileable_type,profileable_id)
+#  index_profiles_on_uuid         (uuid) UNIQUE
 #
 FactoryBot.define do
   factory :profile do
@@ -28,9 +30,14 @@
     github_url { "https://github.com" }
     linkedin_url { "https://linkedin.com" }
     twitter_url { "https://twitter.com" }
+    uuid { SecureRandom.uuid }
 
     trait :with_user do
       association :profileable, factory: :user
     end
+
+    trait :public do
+      is_public { true }
+    end
   end
 end

spec/helpers/profile_helper_spec.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+RSpec.describe ProfileHelper, type: :helper do
+  describe "#qr_code_svg" do
+    let(:profile) { create(:profile, :with_user) }
+
+    it "generates a QR code SVG" do
+      expect(helper.qr_code_svg(profile)).to include("<svg")
+    end
+  end
+end

spec/lib/qr_code_generator_spec.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+RSpec.describe QRCodeGenerator do
+  let(:qr_code_generator) { described_class.new(Faker::Internet.url) }
+
+  describe "#as_svg" do
+    it "returns an SVG" do
+      expect(qr_code_generator.as_svg).to include("<svg")
+    end
+  end
+
+  describe "#as_png" do
+    it "returns a PNG" do
+      expect(qr_code_generator.as_png.to_s).to include("PNG")
+    end
+  end
+end

spec/models/profile_spec.rb

@@ -11,13 +11,15 @@
 #  name             :string
 #  profileable_type :string           not null
 #  twitter_url      :string
+#  uuid             :string
 #  created_at       :datetime         not null
 #  updated_at       :datetime         not null
 #  profileable_id   :integer          not null
 #
 # Indexes
 #
 #  index_profiles_on_profileable  (profileable_type,profileable_id)
+#  index_profiles_on_uuid         (uuid) UNIQUE
 #
 require "rails_helper"
 
@@ -27,4 +29,13 @@
   it "has a valid factory" do
     expect(profile).to be_valid
   end
+
+  describe "callbacks" do
+    let(:profile) { build(:profile, :with_user) }
+
+    it "sets a UUID before creation" do
+      profile.save
+      expect(profile.uuid).to be_present
+    end
+  end
 end