public static IActionResult ValidationError(this ControllerBase controller, ValidationException validationException)
{
controller.Response.Headers.Add(DtoHelper.PayloadTypeHeaderName, DtoHelper.ValidationErrorPayloadType);
var error = WebApiHostHelper.CreateValidationErrorDto(validationException);
return(controller.BadRequest(error));
}
public override void OnActionExecuting(ActionExecutingContext actionContext)
{
ValidationErrorDto validationError = null;
// Verify that the model state is valid before running the argument value specific validators.
if (!actionContext.ModelState.IsValid)
{
// Prepare the validation error response
validationError = ValidationErrorDto.CreateStandard();
foreach (var fieldState in actionContext.ModelState)
{
// Make sure that all the property names are camel cased and remove all model prefixes
var fieldName = WebApiHostHelper.EnsurePropertyNameIsCamelCase(
Regex.Replace(fieldState.Key, @"^(.*?\.)(.*)", "$2"));
// Get only the first error, the rest will be skipped
var error = fieldState.Value.Errors.First();
// Create the error message
var errorMessage = "Unknown error.";
if (!string.IsNullOrEmpty(error.ErrorMessage))
{
errorMessage = error.ErrorMessage;
}
else if (!string.IsNullOrEmpty(error.Exception?.Message))
{
errorMessage = error.Exception.Message;
}
// Add the error to the response, with an empty error code, since this is an unspecific error
validationError.AddFailure(fieldName, null, errorMessage);
}
}
// Validate all the arguments for the current action
foreach (var argument in actionContext.ActionDescriptor./*GetParameters()*/ Parameters)
{
// Skip all arguments without a registered validator
_validatorTypes.TryGetValue(argument.ParameterType, out var validatorType);
if (validatorType == null)
{
continue;
}
// Get the registered validator
var validator = (IValidator)actionContext.HttpContext.RequestServices.GetService(validatorType);
if (validator == null)
{
continue; // could not resolve validator
}
// Inject the action arguments into the validator, so that they can be used in the validation
// This is a "hack" to, amongst other, support unique validation on the update commands where the resource id is needed to exclude itself from the unique check.
if (validator is IParameterValidator)
{
((IParameterValidator)validator).Parameters = actionContext.ActionArguments;
}
// Validate the argument
var argumentValue = actionContext.ActionArguments[argument.Name];
if (argumentValue == null)
{
validationError = ValidationErrorDto.CreateStandard($"Argument '{argument.Name}' is null");
break;
}
var validationResult = validator.Validate(argumentValue);
// Return if the argument value was valid
if (validationResult.IsValid)
{
continue;
}
// Create an validation error response, if it does not already exist
if (validationError == null)
{
validationError = ValidationErrorDto.CreateStandard();
}
// Add every field specific error to validation error response
foreach (var validationFailure in validationResult.Errors)
{
// Make sure that all the property names are camel cased
var propertyName = WebApiHostHelper.EnsurePropertyNameIsCamelCase(validationFailure.PropertyName);
// Only add the first validation message for a property
if (!validationError.Failures.ContainsKey(propertyName))
{
validationError.AddFailure(propertyName, validationFailure.ErrorCode, validationFailure.ErrorMessage);
}
}
}
if (validationError != null)
{
actionContext.Result = new ContentResult
{
StatusCode = StatusCodes.Status400BadRequest,
ContentType = "application/json",
Content = JsonConvert.SerializeObject(validationError),
};
// Set the action response to a 400 Bad Request, with the validation error response as content
actionContext.HttpContext.Response.Headers.Add(DtoHelper.PayloadTypeHeaderName, DtoHelper.ValidationErrorPayloadType);
}
}