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Catch Middleware Decorator

The @Catch decorator registers a global or controller-level error handler.

Purpose​

The @Catch decorator is designed to handle errors that occur within the scope of the decorated target, such as a controller or service. It allows you to define a custom error handling callback that will be invoked whenever an error is thrown, enabling centralized and consistent error management.

Usage​

Apply the @Catch decorator to a class or method and provide an error handler function. This function receives the error and the context in which the error occurred.

Parameters​

  • handler: ErrorHandler - A callback function that handles errors. It typically accepts two parameters: the error object and the context (e.g., request, response, or other relevant data).

Example​

@Catch(async (error, context) => {
  console.error("Error caught:", error);
  // Implement custom error handling logic here
})
class MyController {
  // Controller methods
}

Metadata Handling​

The decorator attaches the error handler as metadata on the target class or method using a specific metadata key (CATCH). This metadata is accessible via the Reflect API and is used internally by the framework to invoke the registered error handler during runtime when errors occur.

Remarks​

  • The error handler can be asynchronous.
  • Multiple error handlers can be registered by applying the decorator multiple times.
  • This decorator helps in separating error handling logic from business logic, improving code maintainability and readability.