Handling Errors With Angular

For software to be dependable and maintained, error management is crucial. Depending on the kind and severity of the problem, there are many ways to address it in Angular.

Use of try-catch blocks is one method for handling mistakes. Try-catch blocks let you capture and deal with exceptions that are thrown while your code is being run. For instance:

try {
  // Code that might raise an exception
} catch (error) {
  // Exception handling code
}

The async-await paradigm may also be used to deal with asynchronous code failures. By using this approach, you may create asynchronous code that reads and functions like synchronous code, making it simpler to debug. For instance:

async function example() {
  try {
    const result = await someAsyncFunction();
    // Use the outcome to your advantage.
  } catch (error) {
    // the error-handling code
  }
}

The ErrorHandler service from Angular offers a global error handler in addition to try-catch blocks and async-await. A service called ErrorHandler is responsible for catching uncaught errors and logging them to the console. By offering your own implementation, the ErrorHandler service may be modified.

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

export class MyErrorHandler implements ErrorHandler {
  handleError(error: any) {
    // specific logic for error handling
  }
}

The HTTP INTERCEPTORS service may also be used to intercept and manage errors that happen during HTTP requests. This can be helpful for resolving 404 (Not Found) and 500 HTTP failures (Internal Server Error).

import { HttpInterceptor, HttpRequest, HttpHandler, HttpErrorResponse } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { Observable, throwError } from 'rxjs';
import { catchError } from 'rxjs/operators';

@Injectable()
export class HttpErrorInterceptor implements HttpInterceptor {
  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return next.handle(request).pipe(
      catchError((error: HttpErrorResponse) => {
        // Handle the error and return a new observable
        return throwError(error);
      })
    );
  }
}

The @Error decorator may also be used to manage problems in Angular components. You may define a function that will be invoked each time an error is thrown inside the component using the @Error decorator.

import { Error } from '@angular/compiler';

@Component({
  // ...
})
export class MyComponent {
  @Error('myErrorHandler')
  myMethod() {
    // coding that might result in an error
  }

  myErrorHandler(error: any) {
    //the error-handling code
  }
}