@ppwcode/ng-async

Override default error extraction

The SDK comes with a default implementation to extract an error from a response. To override this, add an implementation for window.ppwcodeHttpErrorExtractor in your application's main.ts file. For example:

window.ppwcodeHttpErrorExtractor = (response: HttpErrorResponse): Error => {
    return new Error(response.statusText)
}

Custom error handling

The SDK handles errors generically for all error codes present in the DEFAULT_ERROR_CODES constant. When such an error occurs, the SDK will create a failed async result with the error and a null entity.

If you want to handle errors for specific error codes, you can use the expectHttpError operator in combination with the expectAsyncResultHttpError operator.

The below facade example shows how to handle a 404 error using expectHttpError for a service that returns an AuditInfo object. This facade method returns an AsyncResult with status success and fallback value undefined when the audit info is not found.

The expectAsyncResultHttpError operator will handle the other error codes present in the DEFAULT_HTTP_ERROR_CODES constant, excluding what was already handled above. Its fallback value is null, which will trigger the SDK to create a failed async result which will show the default error message.

return this.#service.getAuditInfo().pipe(
    map((result: AuditInfo | null) => createSuccessAsyncResult(result)),
    expectHttpError([HttpStatusCode.NotFound], () => createSuccessAsyncResult(undefined), true),
    expectAsyncResultHttpError(DEFAULT_HTTP_ERROR_CODES, null)
)