10 Advanced Angular Techniques to Level Up Your Development Skills

If you are reading this, it's likely because you are an Angular developer looking to take your skills to the next level. Angular is a powerful platform that has been helping developers build complex web applications for years.

However, there is always room for improvement, and as an Angular developer, you need to stay on top of the latest techniques and trends to ensure you are providing the best user experience possible.

In this article, we will cover ten advanced Angular techniques that you can use to level up your development skills and create better web applications. So, let's get started.

1. Change Detection Strategy

Angular applications are notorious for being slow, but one way to mitigate this issue is by using the OnPush change detection strategy. This strategy is faster than the default strategy because it only runs change detection on certain events instead of every time there is a data change. To implement this strategy, you need to add the changeDetection property to your component and set it to OnPush.

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

@Component({
  selector: 'app-root',
  template: '{{ message }}',
  changeDetection: ChangeDetectionStrategy.OnPush
})
export class AppComponent {
  message = 'Hello World!';
}

2. Dynamic Component Loading

As your Angular application grows, you might find yourself with a need to load components dynamically. This is where the ComponentFactoryResolver class comes in. It allows you to create a component factory that can be used to create instances of a component at runtime. Here's an example of how to use it:

import { Component, ComponentFactoryResolver, ViewChild, ViewContainerRef } from '@angular/core';
import { MyComponent } from './my-component';

@Component({
  selector: 'app-root',
  template: '
'
})
export class AppComponent {
  @ViewChild('container', { read: ViewContainerRef }) container: ViewContainerRef;

  constructor(private resolver: ComponentFactoryResolver) {}

  loadMyComponent() {
    const factory = this.resolver.resolveComponentFactory(MyComponent);
    const componentRef = this.container.createComponent(factory);
  }
}

3. Custom Form Controls

Angular provides a variety of built-in form controls that are useful for most applications. However, if you need a custom form control, you can create one using the ControlValueAccessor interface. This interface allows you to control the value of a form control and listen to changes. Here is an example of how to create a custom form control:

import { Component, forwardRef } from '@angular/core';
import { NG_VALUE_ACCESSOR, ControlValueAccessor } from '@angular/forms';

const MY_CONTROL_VALUE_ACCESSOR = {
  provide: NG_VALUE_ACCESSOR,
  useExisting: forwardRef(() => MyCustomControlComponent),
  multi: true
};

@Component({
  selector: 'app-my-custom-control',
  template: '',
  providers: [MY_CONTROL_VALUE_ACCESSOR]
})
export class MyCustomControlComponent implements ControlValueAccessor {
  value: any;
  onChange = (_: any) => {};
  onTouched = () => {};

  writeValue(value: any) {
    this.value = value;
  }

  registerOnChange(fn: any) {
    this.onChange = fn;
  }

  registerOnTouched(fn: any) {
    this.onTouched = fn;
  }
}

4. Using Observables

Observables are an important part of Angular and are used extensively in the platform. They provide a way to handle asynchronous data in a reactive way. Observables come in handy when you need to communicate between the components or between the client and the server. Most of the Angular built-in services return Observables. Here's an example of how to use Observables:

import { Component } from '@angular/core';
import { Observable } from 'rxjs';

@Component({
  selector: 'app-root',
  template: '{{ message$ | async }}'
})
export class AppComponent {
  message$: Observable<string> = new Observable(observer => {
    setTimeout(() => {
      observer.next('Hello World!');
      observer.complete();
    }, 1000);
  });
}

5. Caching HTTP Requests

HTTP requests can be slow, and in some cases, you might need to make the same request multiple times. In such scenarios, it's a good idea to cache the response. You can use the HttpClient module to add a cache layer to your HTTP requests. This module provides an HttpCacheInterceptor that can be used to cache the HTTP response. Here is an example:

import { NgModule, Injectable } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { HttpClientModule, HttpClient, HttpInterceptor, HttpRequest, HttpResponse, HTTP_INTERCEPTORS } from '@angular/common/http';
import { Observable, of } from 'rxjs';
import { tap, shareReplay } from 'rxjs/operators';

@Injectable()
export class HttpCacheInterceptor implements HttpInterceptor {
  private cache = new Map<string, HttpResponse<any>>();

  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpResponse<any>> {
    if (req.method !== 'GET') {
      return next.handle(req);
    }

    const cachedResponse = this.cache.get(req.url);

    if (cachedResponse) {
      return of(cachedResponse);
    }

    return next.handle(req).pipe(
      tap(response => {
        if (response instanceof HttpResponse) {
          this.cache.set(req.url, response);
        }
      }),
      shareReplay(1)
    );
  }
}

@NgModule({
  imports: [BrowserModule, HttpClientModule],
  providers: [
    {
      provide: HTTP_INTERCEPTORS,
      useClass: HttpCacheInterceptor,
      multi: true
    }
  ],
  bootstrap: [AppComponent]
})
export class AppModule {}

6. Lazy Loading

Lazy loading is a technique used to load modules only when needed, which can significantly reduce the initial loading time of your application. By default, Angular loads all the modules at once when your application is launched, but with lazy loading, you can load a module only when the user navigates to the corresponding route. Here's an example:

import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';

const routes: Routes = [
  {
    path: 'lazy',
    loadChildren: () => import('./lazy/lazy.module').then(m => m.LazyModule)
  }
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule {}

7. ngZone Service

The NgZone service is an important component of Angular that manages the execution of the JavaScript code. It is responsible for running the code in the Angular zone, which handles change detection and other Angular-specific functionality. If you need to execute code outside of the Angular zone, you will need to use the NgZone service. Here's an example:

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

@Component({
  selector: 'app-root',
  template: '{{ message }}'
})
export class AppComponent {
  message = 'Hello World!';

  constructor(private ngZone: NgZone) {}

  performOutsideAngular() {
    this.ngZone.runOutsideAngular(() => {
      // This code will be executed outside the Angular zone.
      // Any changes made here will not trigger change detection.
    });
  }
}

8. Unit Testing

Unit testing is an essential part of software development, and Angular provides many tools to help you test your code. You can use the TestBed module to create a testing module and test your component. Here's an example:

import { ComponentFixture, TestBed } from '@angular/core/testing';
import { MyComponent } from './my-component';

describe('MyComponent', () => {
  let component: MyComponent;
  let fixture: ComponentFixture<MyComponent>;

  beforeEach(async () => {
    await TestBed.configureTestingModule({
      declarations: [ MyComponent ]
    })
    .compileComponents();
  });

  beforeEach(() => {
    fixture = TestBed.createComponent(MyComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

  it('should create', () => {
    expect(component).toBeTruthy();
  });
});

9. Using Pipes

Pipes are a great way to transform data before it is displayed in your Angular application. You can use built-in pipes or create custom pipes to meet your specific needs. Built-in pipes include DatePipe, LowerCasePipe, and UpperCasePipe. Here's an example of using the DatePipe:

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

@Component({
  selector: 'app-root',
  template: '{{ date | date: "dd MMM yyyy" }}'
})
export class AppComponent {
  date = new Date();
}

10. Using Libraries

Finally, one way to boost your Angular development skills is by using libraries that can streamline your workflow. Some popular libraries for Angular include:

•  ngrx: For state management.
•  RxJS: For reactive programming.
•  Angular Material: For UI components.

By using these libraries, you can save time and effort while building more robust and efficient Angular applications.

Conclusion

By applying these advanced Angular techniques, you can take your development skills to the next level. Whether it's optimizing change detection, using Observables, or lazy loading modules, these tips and tricks will help you build more efficient and scalable Angular applications.

Remember, as an Angular developer, there is always room for improvement, so keep learning and exploring these advanced techniques to take your skills to new heights.