Error handling Web Api .net core and Repository Pattern - httpclient

Question

I have question about web api and Repository may be its a duplicate question.
but i tried to search on it and i did not get any satisfactory answer.
In my Repository i am getting data with the help of httpclient.
My question is that i can get an error inside my response or i can get required json data which i can map to my product class.I am returning IEnumerable.
1) If i get an error how can i bubble it up to controller and display an error to user.
2) Return the MessageResponse instead of IEnumerable and handle it inside the controller.
What is the best way.
enter code here
public interface IProduct{
Task<IEnumerable<Product>> All();
}
public class Product:IProduct
{
public async Task<IEnumerable<Product>> All(){
var ResponseMessage=//some response.
}
}

Answer 1

You could customize a ApiException which is used to get the error message of the response, and call the UseExceptionHandler in your startup.cs ,refer to the following :
ProductRep
public class ProductRep : IProduct
{
private readonly HttpClient _client;
public ProductRep(HttpClient client)
{
_client = client;
}
public async Task<IEnumerable<Product>> All()
{
List<Product> productlist = new List<Product>();
var response = await _client.GetAsync("https://localhost:44357/api/values/GetProducts");
string apiResponse = await response.Content.ReadAsStringAsync();
if (response.IsSuccessStatusCode == false)
{
JObject message = JObject.Parse(apiResponse);
var value = message.GetValue("error").ToString();
throw new ApiException(value);
}
productlist = JsonConvert.DeserializeObject<List<Product>>(apiResponse);
return productlist;
}
public class ApiException : Exception
{
public ApiException(string message): base(message)
{ }
}
}
Startup.cs
app.UseExceptionHandler(a => a.Run(async context =>
{
var feature = context.Features.Get<IExceptionHandlerPathFeature>();
var exception = feature.Error;
var result = JsonConvert.SerializeObject(new { error = exception.Message });
context.Response.ContentType = "application/json";
await context.Response.WriteAsync(result);
}));