Angular18 new features | Angular 18 released

Angular 18 introduces several new features and improvements in flexibility, performance, and developer experience. Here are some of the key updates:

👉👉👉Template Local Variable with @let Block | @let in Angular

1. Route Redirects with Functions: Angular 18 allows the redirectTo property in routing configurations to be a function, providing more flexibility in defining redirects based on dynamic conditions. For instance:


export const routes: Routes = [
    {
      path: 'page1',
      redirectTo: (url) => '/page2',
      pathMatch: 'full'
    }
  ];

This function can return either a string or a UrlTree, allowing for complex routing logic based on the current URL state.

Before Angular 18: In previous versions of Angular, the redirectTo property in the route configuration could only accept a static string path. This limited the ability to perform dynamic redirects based on conditions or logic.

const routes: Routes = [
    { path: 'old-path', redirectTo: 'new-path', pathMatch: 'full' }
];

In Angular 18:

With Angular 18, the redirectTo property can now be a function that returns a string or a UrlTree. This allows for more complex and dynamic routing scenarios.


const routes: Routes = [
   {
     path: 'dynamic-redirect',
     redirectTo: (url) => url.includes('special') ? '/special-path' : '/default-path',
     pathMatch: 'full'
   }
 ];

Benefit:

This feature enhances flexibility in routing configurations, enabling developers to create more dynamic and context-aware navigation flows within applications

2. New RedirectCommand: The RedirectCommand class enhances redirection capabilities within guards and resolvers, enabling more maintainable and flexible navigation patterns. It allows you to handle redirection along with NavigationExtras for more control over navigation behaviors.

Before Angular 18: Redirection within guards or resolvers was limited to returning a UrlTree or a boolean. This made it challenging to handle complex navigation behaviors directly within these constructs.


canActivate(): boolean | UrlTree {
    return this.authService.isLoggedIn() ? 
         true : this.router.parseUrl('/login');
  }

In Angular 18:

The introduction of RedirectCommand allows guards to return a RedirectCommand object, which can encapsulate both the target URL and navigation extras.


import { RedirectCommand } from '@angular/router';

canActivate(): RedirectCommand {
  return this.authService.isLoggedIn() 
    ? new RedirectCommand('/home') 
    : new RedirectCommand('/login', 
{ queryParams: { returnUrl: this.router.url } });
}

Benefit:

This provides more control over the redirection process, making it easier to manage navigation extras and creating more readable and maintainable code

3. Zone-less Change Detection: Angular 18 introduces an experimental feature that enables change detection to work without zone.js. This can improve performance by reducing the overhead associated with zones. Developers can now manage application state changes using Angular's own APIs, like ChangeDetectorRef.markForCheck, making applications more efficient and easier to maintain.

Before Angular 18: Angular relied heavily on zone.js change detection, which could introduce performance overhead and complexity, especially in large applications.


import { Component, ChangeDetectorRef } from '@angular/core';

@Component({
  selector: 'app-root',
  template: '<h1>{{ title }}</h1>'
})
export class AppComponent {
  title = 'Hello World';

  constructor(private cdr: ChangeDetectorRef) {}

  updateTitle(newTitle: string) {
    this.title = newTitle;
// manually triggering change detection
    this.cdr.detectChanges();  
  }
}

In Angular 18:

Angular 18 introduces an experimental feature to enable zone-less change detection, allowing developers to handle state changes using Angular's own APIs.


import { bootstrapApplication, ChangeDetectorRef, provideExperimentalZonelessChangeDetection } from '@angular/core';

@Component({
  selector: 'app-root',
  template: '<h1>{{ title }}</h1>'
})
export class AppComponent {
  title = 'Hello World';

  constructor(private cdr: ChangeDetectorRef) {}

  updateTitle(newTitle: string) {
    this.title = newTitle;
 // scheduling change detection
    this.cdr.markForCheck(); 
  }
}

bootstrapApplication(AppComponent, {
  providers: [provideExperimentalZonelessChangeDetection()]
});

Benefit:

This can significantly reduce the overhead associated with change detection, leading to better performance and more predictable application behavior.

4. Improved Forms API: The forms module has seen several enhancements, including new events for state changes in AbstractControl and FormControlStatus. This allows developers to better track changes in form controls and manage dynamic forms more effectively.

Before Angular 18: The forms API in Angular was already powerful, but managing dynamic forms and reacting to control state changes required more boilerplate code and wasn't as streamlined.


import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';

@Component({
  selector: 'app-form',
  templateUrl: './form.component.html'
})
export class FormComponent implements OnInit {
  form: FormGroup;

  constructor(private fb: FormBuilder) {}

  ngOnInit() {
    this.form = this.fb.group({
      name: ['', Validators.required]
    });
  }
}

In Angular 18:

Angular 18 enhances the forms API by introducing new events for value and state changes, making it easier to manage complex form interactions.


import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';

@Component({
  selector: 'app-form',
  templateUrl: './form.component.html'
})
export class FormComponent implements OnInit {
  form: FormGroup;

  constructor(private fb: FormBuilder) {}

  ngOnInit() {
    this.form = this.fb.group({
      name: ['', Validators.required]
    });

    this.form.valueChanges.subscribe(value => {
      console.log('Form value changed:', value);
    });

    this.form.statusChanges.subscribe(status => {
      console.log('Form status changed:', status);
    });
  }
}

Benefit:

These enhancements streamline the process of handling dynamic forms, making it easier to track and react to changes in form controls, thus improving the overall development experience and maintainability

5. Enhanced Angular DevTools: The latest version includes improvements to the Angular DevTools, making debugging easier with better logging, enhanced breakpoints, and real-time data inspection capabilities. This helps developers quickly identify and resolve issues within their applications.

Before Angular 18: While Angular DevTools provided basic debugging functionalities, it lacked advanced features for in-depth inspection and real-time debugging within the development environment.

In Angular 18: Angular 18 introduces advanced debugging tools, including improved logging, enhanced breakpoints, and real-time data inspection capabilities integrated with popular IDEs.


import { Component, OnInit } from '@angular/core';
import { DataService } from './data.service';

@Component({
  selector: 'app-user-list',
  templateUrl: './user-list.component.html'
})
export class UserListComponent implements OnInit {
  users: any[];

  constructor(private dataService: DataService) {}

  ngOnInit() {
    this.dataService.getUsers().subscribe({
      next: (data) => {
        this.users = data;
// Enhanced debugging statement
        console.debug('Users loaded:', this.users); 
      },
      error: (error) => {
// Error handling with detailed debugging
        console.error('Error loading users:', error); 
      }
    });
  }
}

Benefit:

These advanced tools help developers quickly identify and resolve issues, making the debugging process more intuitive and efficient. This leads to faster development cycles and more robust applications

6. Support for TypeScript 5.4: Angular 18 supports TypeScript 5.4, allowing developers to leverage the latest features and improvements in TypeScript for better performance and developer experience.

Before Angular 18: Earlier versions of Angular supported older versions of TypeScript, which lacked some of the newer features and performance improvements.

In Angular 18: Angular 18 supports TypeScript 5.4, enabling developers to use the latest TypeScript features and improvements.


// TypeScript 5.4 features, e.g.,
// new type utility improvements
type MyPartial<T> = {
    [P in keyof T]?: T[P];
  };
  
  interface User {
    name: string;
    age: number;
  }
  
 const partialUser: MyPartial<User> = { name: 'theDotNetOffice' };

Benefit:

This ensures better performance, new language features, and improved developer experience, keeping Angular applications up-to-date with modern TypeScript capabilities

7. Material 3 is now stable:

So after many developers demanded material 3 was introduced a couple of months ago, and is now stable in angular 18.

Material 3 in Angular refers to the integration of the Material Design 3 (M3) specification into Angular applications through the Angular Material library. Material Design 3 is the latest iteration of Google's design system, known for its emphasis on personalization, dynamic color, and improved accessibility.

These features, along with various core improvements and enhanced internationalization capabilities, make Angular 18 a significant update that aims to improve both performance and developer productivity.

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