Angular provides robust mechanisms for handling errors in applications. Here's a guide to help you manage errors effectively:

🛠️ Introduction to Error Handling

When developing Angular apps, errors can occur in various scenarios like network issues, invalid data, or unexpected exceptions. Proper error handling ensures a better user experience and easier debugging.

  • Local Error Handling: Use try/catch blocks in components/services
  • Global Error Handling: Implement ErrorHandler interface
  • Navigation Errors: Handle errors during routing with NavigationErrorEvent

⚠️ Common Error Types

Error Type Description Example
HttpErrorResponse Errors from HTTP requests catchError operator
ErrorEvent Errors during navigation NavigationErrorEvent
ComponentErrors Errors within component logic try...catch in lifecycle hooks

📦 Handling Errors in Components

Use HttpClient with error handling operators:

import { HttpClient } from '@angular/common/http';
import { catchError, throwError } from 'rxjs';

this.http.get('/api/data').pipe(
  catchError((error) => {
    console.error('API Error:', error);
    return throwError(() => new Error('Something went wrong!'));
  })
).subscribe(data => {
  // Handle success
});

🌐 Global Error Handling

Implement a custom ErrorHandler:

import { ErrorHandler, NgZone } from '@angular/core';
import { HttpException } from '@angular/common/http';

export class GlobalErrorHandler implements ErrorHandler {
  constructor(private zone: NgZone) {}

  handleError(error: any): void {
    console.error('Global Error:', error);
    this.zone.run(() => {
      // Display error message to user
    });
  }
}

📚 Best Practices

  • Use Angular's built-in error handling utilities
  • Log errors to a centralized service
  • Show user-friendly messages instead of technical errors
  • Test error scenarios with Angular's TestBed

For more advanced error handling techniques, check out our Angular Advanced Features documentation. 🚀

Angular_Error_Handling