Reactive Programming

Table of Contents

• [Overview](#overview)
• [When to Use](#when-to-use)
• [Quick Start](#quick-start)
• [Reference Guides](#reference-guides)
• [Best Practices](#best-practices)

Overview

Build responsive applications using reactive streams and observables for handling asynchronous data flows.

When to Use

• Complex async data flows
• Real-time data updates
• Event-driven architectures
• UI state management
• WebSocket/SSE handling
• Combining multiple data sources

Quick Start

Minimal working example:

import {
  Observable,
  Subject,
  BehaviorSubject,
  fromEvent,
  interval,
} from "rxjs";
import {
  map,
  filter,
  debounceTime,
  distinctUntilChanged,
  switchMap,
} from "rxjs/operators";

// Create observable from array
const numbers$ = new Observable<number>((subscriber) => {
  subscriber.next(1);
  subscriber.next(2);
  subscriber.next(3);
  subscriber.complete();
});

numbers$.subscribe({
  next: (value) => console.log(value),
// ... (see reference guides for full implementation)

Reference Guides

Detailed implementations in the references/ directory:

Best Practices

✅ DO

• Unsubscribe to prevent memory leaks
• Use operators to transform data
• Handle errors properly
• Use shareReplay for expensive operations
• Combine streams when needed
• Test reactive code

❌ DON'T

• Subscribe multiple times to same observable
• Forget to unsubscribe
• Use nested subscriptions
• Ignore error handling
• Make observables stateful