State Management in Angular

we’ll explore State Management in Angular, focusing on how to manage application state effectively in complex applications. As applications grow, managing shared states and keeping track of changes across components becomes a challenge. We will cover core concepts of state management and introduce tools like NgRx that can help manage application state efficiently.

1. What is State Management?

State refers to the data that represents the status of an application at any given moment. In Angular, state management is the process of managing this data consistently across different parts of the app. Managing state ensures that data is updated and synchronized across components, preventing inconsistency and improving maintainability.

There are two types of state in Angular applications:

• Local State: Data confined to a single component.
• Shared State: Data shared between multiple components.

For small to medium applications, managing state using services and local component data might be sufficient. However, for larger applications with complex UI flows and shared data, tools like NgRx come into play.

2. Angular Services for State Management

Before diving into advanced state management libraries, Angular’s services provide a built-in way to manage state and share it between components. Here’s how services can be used for state management:

2.1. Using a Service to Hold State

You can create a service that holds the application’s state and inject it into multiple components to share data between them.

• Example Service:

import { Injectable } from '@angular/core';

@Injectable({
  providedIn: 'root'
})
export class AppStateService {
  private _counter = 0;

  get counter() {
    return this._counter;
  }

  incrementCounter() {
    this._counter++;
  }
}        

2.2. Injecting the Service into Components

You can then inject the service into a component to access and update the shared state.

• Example Usage:

import { Component } from '@angular/core';
import { AppStateService } from './app-state.service';

@Component({
  selector: 'app-counter',
  template: `
    <button (click)="increment()">Increment</button>
    <p>Counter: {{ appState.counter }}</p>
  `
})
export class CounterComponent {
  constructor(public appState: AppStateService) {}

  increment() {
    this.appState.incrementCounter();
  }
}        

This works well for simple applications, but as complexity increases, handling shared state can become cumbersome. That’s where NgRx and other state management libraries help.

Read More: https://www.hqledutech.com/state-management-in-angular/