The “Bible” for Rails Development: Fully Updated for Rails 5 “When I read The Rails Way for the first time, I felt like I truly understood Rails for the first time.” —Steve Klabnik, Rails contributor and mentor The Rails™ 5 Way is the comprehensive, authoritative reference guide for professionals delivering production-quality code using modern Ruby on Rails. Obie Fernandez illuminates the entire Rails 5 API, its most powerful idioms, design approaches, and libraries. He presents new and updated content on Action Cable, RSpec 3.4, Turbolinks 5.0, the Attributes API, and many other enhancements, both major and subtle.   Through detailed code examples, you’ll dive deep into Ruby on Rails, discover why it’s designed as it is, and learn to make it do exactly what you want. Proven in thousands of production systems, the knowledge in this book will maximize your productivity and help you build more successful solutions. Build powerful, scalable, REST-compliant back-end services Program complex program flows using Action Controller Represent models, relationships, and operations in Active Record, and apply advanced Active Record techniques Smoothly evolve database schema via Migrations Craft front-ends with ActionView and the Asset Pipeline Optimize performance and scalability with caching and Turbolinks 5.0 Improve your productivity using Haml HTML templating Secure your systems against attacks like SQL Injection, XSS, and XSRF Integrate email using Action Mailer Enable real-time, websockets-based browser behavior with Action Cable Improve responsiveness with background processing Build “API-only” back-end projects that speak JSON Leverage enhancements to Active Job, serialization, and Ajax support

Table of Contents:
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