Reactive Patterns with RxJS and Angular Signals: Elevate your Angular 18 applications with RxJS Observables, subjects, operators, and Angular Signals. 2 Ed

Cover....1 Title Page....2 Copyright and Credits....3 Dedication....4 Foreword....5 Contributors....6 Table of Contents....8 Preface....14 Part 1: An Introduction to the Reactive World....20 Chapter 1: Diving into the Reactive Paradigm....22 Technical requirements....23 Exploring the pillars of reactive programming....23 Data streams....23 Observer patterns....24 Learning about the marble diagram (our secret weapon)....25 Highlighting the use of RxJS in Angular....28 The HttpClient module....28 The Router module....29 Reactive forms....32 The Event emitter....32 Summary....33 Chapter 2: Walking through Our Application....34 Technical requirements....34 Breaking down our app’s interfaces....35 View one – the landing page....35 View two – the New Recipe interface....36 View three – the My Recipes interface....37 View four – the My Favourites interface....38 View five – the Modify Recipe interface....38 View six – the Recipe Details interface....39 Reviewing our app’s architecture....39 Reviewing our app’s components....40 Summary....41 Part 2: A Trip into Reactive Patterns....42 Chapter 3: Fetching Data as Streams....44 Technical requirements....45 Defining the data fetch requirement....46 Exploring the classic pattern for fetching data....47 Defining the structure of your data....47 Creating the fetching data service....47 Creating Angular standalone components....49 Injecting and subscribing to the service in your component....52 Displaying the data in the template....53 Managing unsubscriptions....54 Exploring the reactive pattern for fetching data....57 Retrieving data as streams....57 Defining the stream in your component....58 Using the async pipe in your template....59 Highlighting the advantages of the reactive pattern....60 Using the declarative approach....60 Using the change detection strategy of OnPush....61 Diving into the built-in control flow in Angular 17....63 Structural directives....64 Built-in control flows....65 Including built-in control flows in our recipe app....69 Benefits of built-in control flow....70 Summary....71 Chapter 4: Handling Errors Reactively....72 Technical requirements....72 Understanding the anatomy of an Observable contract....73 Exploring error handling patterns and strategies....74 The replace strategy....76 The rethrow strategy....78 The retrying strategy....79 Choosing the right error handling strategy....85 Handling errors in our recipe app....87 Summary....89 Chapter 5: Combining Streams....90 Technical requirements....90 Defining the filtering requirement....91 Exploring the imperative pattern for filtering data....92 Exploring the declarative pattern for filtering data....95 The combineLatest operator....97 Updating the filter value....100 Highlighting common pitfalls and best practices....103 Unnecessary subscriptions....103 Missing or incomplete values....104 Performance overhead....104 Confusing error handling....104 Summary....104 chapter 6: Transforming Streams....106 Technical requirements....106 Defining the autosave requirement....107 Exploring the imperative pattern for the autosave feature....108 Exploring the reactive pattern for the autosave feature....111 Higher-order Observables....111 Higher-order mapping operators....112 Summary....128 Chapter 7: Sharing Data between Angular Components....130 Technical requirements....130 Defining the sharing data requirement....131 Exploring the reactive pattern to share data....131 Step 1 – Creating a shared service....132 Step 2 – Updating the last selected recipe....133 Step 3 – Consuming the last selected recipe....136 Wrapping up the data-sharing reactive pattern....137 Leveraging Deferrable Views in Angular 17....138 Summary....139 Part 3: The Power of Angular Signals....140 Chapter 8: Mastering Reactivity with Angular Signals....142 Technical requirements....142 Understanding the motivation behind Signals....143 The traditional Zone.js approach....143 The new Signals approach....143 Unveiling the Signal API....144 Defining Signals....144 Creating Signals using the constructor function....145 Reading Signals....146 Modifying a writable Signal....147 Computed Signals....148 Signal effects....149 Unlocking the power of RxJS and Angular Signals....149 Understanding the behavior of toSignal()....151 Understanding the behavior of toObservable()....153 Integrating Signals into our recipe app....155 Fetching data as streams using Signals....155 Combining streams using Signals....158 Sharing data using Signals....160 Transforming streams using Signals....161 Exploring reactive data binding with Signals....163 Signal inputs....163 Model inputs....165 Signal queries....166 Summary....167 Part 4: Multicasting Adventures....168 Chapter 9: Demystifying Multicasting....170 Technical requirements....170 Explaining multicasting versus unicasting....170 Unicasting and cold Observables....171 Multicasting and hot Observables....172 Transforming cold Observables into hot Observables....174 Exploring RxJS subjects....175 A plain subject....176 replaySubject....177 BehaviorSubject....178 Highlighting the advantages of multicasting....181 Summary....182 Chapter 10: Boosting Performance with Reactive Caching....184 Technical requirements....184 Defining the caching requirement....185 Exploring the reactive pattern to cache streams....186 The shareReplay operator....186 Using shareReplay in RecipesApp....187 Customizing the shareReplay operator....189 Replacing the shareReplay operator with the share operator....191 Highlighting the use of caching for side effects....193 Summary....194 Chapter 11: Performing Bulk Operations....196 Technical requirements....196 Defining the bulk operation requirements....197 Learning the reactive pattern for bulk operations....198 The forkJoin operator....199 The bulk operation reactive pattern....200 Benefits of the forkJoin operator....203 Learning the reactive pattern for tracking the bulk operation’s progress....204 Summary....206 Chapter 12: Processing Real-Time Updates....208 Technical requirements....208 Defining the requirements of real time....209 Learning the reactive pattern for consuming real-time messages....210 Creating and using WebSocketSubject....210 WebSocketSubject in action....214 Learning the reactive pattern for handling reconnection....220 Summary....223 Part 5: Final Touches....224 Chapter 13: Testing RxJS Observables....226 Technical requirements....226 Learning about the subscribe and assert pattern....227 Testing single-value output methods....227 Testing multiple-value output methods....230 Testing timed-value output methods....231 Learning about the marble testing pattern....232 Understanding the syntax....232 Introducing TestScheduler....233 Implementing marble tests....235 Testing timed-value output methods....237 Highlighting testing streams using HttpClientTestingModule....239 Summary....241 Index....244 Other Books You May Enjoy....251