The Rails 5 Way

Foreword by Giles Bowkett xlix

Foreword to the Previous Edition by Steve Klabnik liii

Foreword to the Previous Edition by David Heinemeier Hansson lv

Foreword to the Previous Edition by Yehuda Katz lvii

Introduction lix

Acknowledgments lxv

About the Author lxvii





Chapter 1: Rails Configuration and Environments 1

1.1 Bundler 2

1.2 Startup Scripts 10

1.3 Default Initializers 12

1.4 Other Common Initializers 19

1.5 Spring Application Preloader 21

1.6 Development Mode 22

1.7 Test Mode 27

1.8 Production Mode 29

1.9 Configuring a Database 32

1.10 Configuring Application Secrets 33

1.11 Logging 34

1.12 Conclusion 41



Chapter 2: Routing 43

2.1 The Two Purposes of Routing 44

2.2 The routes.rb File 45

2.3 Route Globbing 57

2.4 Named Routes 58

2.5 Scoping Routing Rules 63

2.6 Listing Routes 66

2.7 Conclusion 66



Chapter 3: REST, Resources, and Rails 69

3.1 REST in a Rather Small Nutshell 70

3.2 Resources and Representations 71

3.3 REST in Rails 71

3.4 Routing and CRUD 72

3.5 The Standard RESTful Controller Actions 76

3.6 Singular Resource Routes 80

3.7 Nested Resources 80

3.8 Routing Concerns 85

3.9 RESTful Route Customizations 86

3.10 Controller-Only Resources 91

3.11 Different Representations of Resources 93

3.12 The RESTful Rails Action Set 95

3.13 Conclusion 100



Chapter 4: Working with Controllers 101

4.1 Rack 102

4.2 Action Dispatch: Where It All Begins 105

4.3 Render unto View . . . 108

4.4 Additional Layout Options 120

4.5 Redirecting 121

4.6 Controller/View Communication 124

4.7 Action Callbacks 125

4.8 Streaming 131

4.9 Variants 138

4.10 Conclusion 139



Chapter 5: Working with Active Record 141

5.1 The Basics 142

5.2 Macro-Style Methods 143

5.3 Defining Attributes 146

5.4 CRUD: Creating, Reading, Updating, Deleting 149

5.5 Database Locking 162

5.6 Querying 166

5.7 Ignoring Columns 185

5.8 Connections to Multiple Databases in Different Models 186

5.9 Using the Database Connection Directly 187

5.10 Custom SQL Queries 191

5.11 Other Configuration Options 193

5.12 Conclusion 194



Chapter 6: Active Record Migrations 195

6.1 Creating Migrations 195

6.2 Defining Columns 207

6.3 Transactions 214

6.4 Data Migration 214

6.5 Database Schema 218

6.6 Database Seeding 219

6.7 Database-Related Tasks 220

6.8 Conclusion 224



Chapter 7: Active Record Associations 225

7.1 The Association Hierarchy 225

7.2 One-to-Many Relationships 226

7.3 Belongs to Associations 227

7.4 Has Many Associations 238

7.5 Many-to-Many Relationships 253

7.6 One-to-One Relationships 266

7.7 Working with Unsaved Objects and Associations 270

7.8 Association Extensions 272

7.9 The CollectionProxy Class 274

7.10 Conclusion 275



Chapter 8: Validations 277

8.1 Finding Errors 277

8.2 The Simple Declarative Validations 278

8.3 Common Validation Options 289

8.4 Conditional Validation 291

8.5 Short-Form Validation 293

8.6 Custom Validation Techniques 294

8.7 Skipping Validations 297

8.8 Working with the Errors Hash 298

8.9 Testing Validations with Shoulda 298

8.10 Conclusion 299



Chapter 9: Advanced Active Record 301

9.1 Scopes 302

9.2 Callbacks 306

9.3 Attributes API 317

9.4 Serialized Attributes 325

9.5 Enums 329

9.6 Generating Secure Tokens 331

9.7 Calculation Methods 333

9.8 Batch Operations 334

9.9 Single-Table Inheritance (STI) 344

9.10 Abstract Base Model Classes 351

9.11 Polymorphic has_many Relationships 352

9.12 Foreign-Key Constraints 355

9.13 Modules for Reusing Common Behavior 359

9.14 Value Objects 363

9.15 Non-persisted Models 366

9.16 Modifying Active Record Classes at Runtime 368

9.17 PostgreSQL 371

9.18 Conclusion 376



Chapter 10: Action View 377

10.1 Layouts and Templates 378

10.2 Partials 387

10.3 Conclusion 393



Chapter 11: All about Helpers 395

11.1 ActiveModelHelper 395

11.2 AssetTagHelper 396

11.3 AssetUrlHelper 400

11.4 AtomFeedHelper 406

11.5 CacheHelper 408

11.6 CaptureHelper 408

11.7 ControllerHelper 410

11.8 CsrfHelper 410

11.9 DateHelper 411

11.10 DebugHelper 418

11.11 FormHelper 418

11.12 FormOptionsHelper 438

11.13 FormTagHelper 446

11.14 JavaScriptHelper 452

11.15 NumberHelper 453

11.16 OutputSafetyHelper 457

11.17 RecordTagHelper 458

11.18 RenderingHelper 459

11.19 SanitizeHelper 459

11.20 TagHelper 461

11.21 TextHelper 463

11.22 TranslationHelper and the I18n API 467

11.23 UrlHelper 487

11.24 Writing Your Own View Helpers 492

11.25 Wrapping and Generalizing Partials 495

11.26 Conclusion 501



Chapter 12: Haml 503

12.1 Getting Started 504

12.2 The Basics 504

12.3 Doctype 509

12.4 Comments 509

12.5 Evaluating Ruby Code 510

12.6 Helpers 513

12.7 Filters 514

12.8 Haml and Content 515

12.9 Configuration Options 516

12.10 Conclusion 518



Chapter 13: Session Management 519

13.1 What to Store in the Session 520

13.2 Storage Mechanisms 521

13.3 Cookies 524

13.4 Conclusion 526



Chapter 14: Authentication and Authorization 527

14.1 Warden 527

14.2 Devise 531

14.3 has_secure_password 544

14.4 Pundit 549

14.5 Conclusion 555



Chapter 15: Security 557

15.1 Password Management 558

15.2 Log Masking 560

15.3 SSL (Secure Sockets Layer) 560

15.4 Model Mass-Assignment Attributes Protection 561

15.5 SQL Injection 564

15.6 Cross-Site Scripting (XSS) 566

15.7 XSRF (Cross-Site Request Forgery) 569

15.8 Session Fixation Attacks 572

15.9 Keeping Secrets 572

15.10 Conclusion 574



Chapter 16: Action Mailer 575

16.1 Mailer Models 575

16.2 Previews 585

16.3 Receiving Emails 587

16.4 Testing Email Content 589

16.5 Sending via API 590

16.6 Configuration 591

16.7 Conclusion 592



Chapter 17: Caching and Performance 593

17.1 View Caching 593

17.2 Data Caching 610

17.3 Control of Web Caching 612

17.4 ETags 614

17.5 Conclusion 615



Chapter 18: Background Processing 617

18.1 Active Job 617

18.2 Queueing Backends 622

18.3 Rails Runner 634

18.4 Conclusion 636



Chapter 19: Asset Pipeline 637

19.1 Introduction to Asset Management 638

19.2 Organization. Where Does Everything Go? 639

19.3 Manifest Files 640

19.4 Custom Format Handlers 645

19.5 Post-Processing 646

19.6 Helpers 647

19.7 Fingerprinting 649

19.8 Serving the Files 650

19.9 Rake Tasks 653

19.10 Yarn 654

19.11 Webpack 656

19.12 Conclusion 660



Chapter 20: Ajax on Rails 661

20.1 Unobtrusive JavaScript 662

20.2 Ajax and JSON 666

20.3 Ajax and HTML 668

20.4 JSONP Requests 669

20.5 Conclusion 671



Chapter 21: Turbolinks 673

21.1 Turbolinks Usage 674

21.2 Building Your Turbolinks Application 676

21.3 Understanding Turbolinks Caching 677

21.4 Making Transformations Idempotent 679

21.5 Responding to Page Updates 679

21.6 Persisting Elements across Page Loads 680

21.7 Advanced Turbolinks 681

21.8 Turbolinks API Reference 683

21.9 Turbolinks Events 684

21.10 Conclusion 685



Chapter 22: Action Cable 687

22.1 Web Sockets 687

22.2 Publish-Subscribe Pattern 688

22.3 Connections 688

22.4 Channels 689

22.5 Subscriptions 690

22.6 Streams 691

22.7 Subscriptions Revisited (Browser-Side) 691

22.8 Rebroadcasting 691

22.9 Channel Actions 692

22.10 Configuration 694

22.11 Running Stand-Alone Cable Servers 696

22.12 Generator 696

22.13 Conclusion 697



Chapter 23: RSpec 699

23.1 Introduction 699

23.2 Behavior-Driven Development 700

23.3 Basic Syntax and API 702

23.4 Custom Expectation Matchers 716

23.5 Helper Methods 719

23.6 Shared Behaviors 720

23.7 Shared Context 721

23.8 Mocks and Stubs 721

23.9 Running Specs 724

23.9.2 Filtering 726

23.10 Factory Girl 726

23.11 RSpec and Rails 738

23.12 Feature Specs with Capybara 752

23.13 Working with Files in Your Specs 754

23.14 RSpec Tools 755

23.15 Conclusion 758



Appendix A: Active Model API Reference 761

A.1 AttributeAssignment 761

A.2 AttributeMethods 762

A.3 Callbacks 764

A.4 Conversion 766

A.5 Dirty 766

A.6 Errors 769

A.7 ForbiddenAttributesError 774

A.8 Lint::Tests 775

A.9 MissingAttributeError 776

A.10 Model 776

A.11 Name 778

A.12 Naming 780

A.13 SecurePassword 781

A.14 Serialization 781

A.15 Serializers::JSON 782

A.16 Translation 784

A.17 Type 785

A.18 ValidationError 786

A.19 Validations 786

A.20 Validator 792



Appendix B: Active Support API Reference 795

B.1 Array 796

B.2 Autoload 803

B.3 BacktraceCleaner 805

B.4 Benchmark 806

B.5 Benchmarkable 806

B.6 BigDecimal 807

B.7 Cache::FileStore 807

B.8 Cache::MemCacheStore 808

B.9 Cache::MemoryStore 808

B.10 Cache::NullStore 809

B.11 Cache::Store 809

B.12 CachingKeyGenerator 814

B.13 Callbacks 815

B.14 Class 817

B.15 Concern 820

B.16 Configurable 821

B.17 Date 821

B.18 DateAndTime 831

B.19 DateTime 834

B.20 Dependencies 838

B.21 DescendantsTracker 843

B.22 Digest::UUID 843

B.23 Duration 844

B.24 Enumerable 846

B.25 ERB::Util 847

B.26 EventedFileUpdateChecker 848

B.27 FalseClass 849

B.28 File 849

B.29 FileUpdateChecker 849

B.30 Gzip 851

B.31 Hash 851

B.32 HashWithIndifferentAccess 857

B.33 Inflector 858

B.34 Inflector::Inflections 858

B.35 Integer 862

B.36 JSON 863

B.37 Kernel 863

B.38 KeyGenerator 864

B.39 LazyLoadHooks 865

B.40 Locale 866

B.41 LogSubscriber 869

B.42 Logger 870

B.43 MessageEncryptor 871

B.44 MessageVerifier 872

B.45 Module 872

B.46 Module::Concerning 879

B.47 Multibyte::Chars 880

B.48 Multibyte::Unicode 883

B.49 NameError 884

B.50 NilClass 885

B.51 Notifications 886

B.52 NumberHelper 889

B.53 Numeric 890

B.54 Object 898

B.55 OrderedOptions 904

B.56 ProxyObject 904

B.57 Railtie 905

B.58 Range 906

B.59 Regexp 907

B.60 Rescuable 907

B.61 SecureRandom 909

B.62 SecurityUtils 909

B.63 String 909

B.64 StringInquirer 918

B.65 Subscriber 919

B.66 TaggedLogging 919

B.67 TestCase 919

B.68 Testing::Assertions 921

B.69 Thread 924

B.70 Time 925

B.71 TimeWithZone 935

B.72 TimeZone 936

B.73 TrueClass 940

B.74 XmlMini 940



Appendix C: Rails API 943

C.1 Rails API Mode 944

C.2 JSON 945



Index 951