Exception Handling

Vaden includes a powerful exception handling mechanism inspired by Spring Boot’s @ControllerAdvice. It allows you to define global error handling logic in a centralized and reusable way.

ControllerAdvice

Classes annotated with @ControllerAdvice() act as global interceptors for uncaught exceptions that occur during request processing.

Each method inside this class can be annotated with @ExceptionHandler(SomeException) to catch and handle a specific type of exception. You can inject dependencies into the advice class like any other component.

@ControllerAdvice()
class AppControllerAdvice {
  final DSON _dson;
  AppControllerAdvice(this._dson);

  @ExceptionHandler(ResponseException)
  Future<Response> handleResponseException(ResponseException e) async {
    return e.generateResponse(_dson);
  }

  @ExceptionHandler(Exception)
  Response handleGeneric(Exception e) {
    return Response.internalServerError(
      body: jsonEncode({'message': 'Internal server error'}),
    );
  }
}

• The first method catches ResponseException and uses a custom method to generate a response.
• The second method handles any uncaught Exception as a fallback.

Design Notes

• All @ExceptionHandler() methods must return Response or Future<Response>.
• You can have multiple @ControllerAdvice() classes if needed.
• The closest match (based on type hierarchy) will be used.
• Dependency injection is fully supported.

This exception handling system gives you clean, centralized control over error formatting, status codes, and custom logic without scattering try/catch blocks throughout your controllers.