Getting Started with Angular Signals

Angular Signals represent a revolutionary approach to reactive programming in Angular applications. Introduced in Angular 16, signals provide a simpler and more intuitive way to handle state management compared to traditional RxJS-based solutions.

What are Signals?

A signal is a wrapper around a value that can notify interested consumers when that value changes. Think of it as a reactive variable that automatically updates the UI whenever its value changes.

Creating Your First Signal

Here's how to create a basic signal:

import { signal } from '@angular/core';
const count = signal(0);
// Reading the value
console.log(count()); // 0
// Setting a new value
count.set(5);
// Updating based on current value
count.update(value => value + 1);

Computed Signals

Computed signals derive their value from other signals:

import { signal, computed } from '@angular/core';
const price = signal(100);
const quantity = signal(2);
const total = computed(() => price() * quantity());
// total() will automatically update when price or quantity changes

Effects

Effects allow you to run side effects when signals change:

import { signal, effect } from '@angular/core';
const user = signal({ name: 'John' });
effect(() => {
  console.log(User changed: ${user().name});
});

Best Practices

1. Keep signals focused - Each signal should represent a single piece of state 2. Use computed for derived state - Don't duplicate state that can be computed 3. Leverage effect sparingly - Only use effects for side effects, not for state derivation

Conclusion

Angular Signals offer a powerful and intuitive way to manage state in your applications. They're simpler than RxJS for many common use cases while still being fully compatible with Observable-based code.

Start experimenting with signals in your next Angular project and experience the difference!