public Task BindModelAsync(ModelBindingContext bindingContext)
{
if (bindingContext == null)
{
throw new ArgumentNullException(nameof(bindingContext));
}
var modelType = bindingContext.ModelType;
if (modelType != typeof(Date) && modelType != typeof(Date?))
{
throw new InvalidOperationException($"Cannot bind {modelType.Name}.");
}
var dayModelName = $"{bindingContext.ModelName}.{DayComponentName}";
var monthModelName = $"{bindingContext.ModelName}.{MonthComponentName}";
var yearModelName = $"{bindingContext.ModelName}.{YearComponentName}";
var dayValueProviderResult = bindingContext.ValueProvider.GetValue(dayModelName);
var monthValueProviderResult = bindingContext.ValueProvider.GetValue(monthModelName);
var yearValueProviderResult = bindingContext.ValueProvider.GetValue(yearModelName);
// If all components are empty and ModelType is nullable then bind null to result
if (dayValueProviderResult == ValueProviderResult.None &&
monthValueProviderResult == ValueProviderResult.None &&
yearValueProviderResult == ValueProviderResult.None)
{
if (modelType == typeof(Date?))
{
bindingContext.Result = ModelBindingResult.Success(null);
}
else
{
bindingContext.Result = ModelBindingResult.Failed();
}
return(Task.CompletedTask);
}
int day = -1;
int month = -1;
int year = -1;
bool yearIsValid = false, monthIsValid = false, dayIsValid = false;
if ((yearIsValid = TryParseYear()) && (monthIsValid = TryParseMonth()) && (dayIsValid = TryParseDay()))
{
var date = new Date(year, month, day);
bindingContext.Result = ModelBindingResult.Success(date);
}
else
{
bindingContext.ModelState.SetModelValue(dayModelName, dayValueProviderResult);
bindingContext.ModelState.SetModelValue(monthModelName, monthValueProviderResult);
bindingContext.ModelState.SetModelValue(yearModelName, yearValueProviderResult);
DateParseErrorComponents errorComponents = DateParseErrorComponents.None |
(!dayIsValid ? DateParseErrorComponents.Day : DateParseErrorComponents.None) |
(!monthIsValid ? DateParseErrorComponents.Month : DateParseErrorComponents.None) |
(!yearIsValid ? DateParseErrorComponents.Year : DateParseErrorComponents.None);
bindingContext.ModelState.TryAddModelError(
bindingContext.ModelName,
new DateParseException("Invalid date specified.", errorComponents),
bindingContext.ModelMetadata);
bindingContext.Result = ModelBindingResult.Failed();
}
return(Task.CompletedTask);
bool TryParseDay()
{
if (dayValueProviderResult != ValueProviderResult.None &&
dayValueProviderResult.FirstValue != string.Empty)
{
if (!int.TryParse(dayValueProviderResult.FirstValue, out day) ||
day < 1 ||
(month != -1 && year != -1 && day > DateTime.DaysInMonth(year, month)))
{
bindingContext.ModelState.TryAddModelError(
dayModelName,
"Day is not valid.");
bindingContext.ModelState.TryGetValue(bindingContext.ModelName, out var x);
return(false);
}
else
{
return(true);
}
}
else
{
bindingContext.ModelState.TryAddModelError(
dayModelName,
"Day is missing.");
return(false);
}
}
bool TryParseMonth()
{
if (monthValueProviderResult != ValueProviderResult.None &&
monthValueProviderResult.FirstValue != string.Empty)
{
if (!int.TryParse(monthValueProviderResult.FirstValue, out month) ||
month < 1 ||
month > 12)
{
bindingContext.ModelState.TryAddModelError(
monthModelName,
"Month is not valid.");
return(false);
}
else
{
return(true);
}
}
else
{
bindingContext.ModelState.TryAddModelError(
monthModelName,
"Month is missing.");
return(false);
}
}
bool TryParseYear()
{
if (yearValueProviderResult != ValueProviderResult.None &&
yearValueProviderResult.FirstValue != string.Empty)
{
if (!int.TryParse(yearValueProviderResult.FirstValue, out year) ||
year < 1 ||
year > 9999)
{
bindingContext.ModelState.TryAddModelError(
yearModelName,
"Year is not valid.");
return(false);
}
else
{
return(true);
}
}
else
{
bindingContext.ModelState.TryAddModelError(
yearModelName,
"Year is missing.");
return(false);
}
}
}
internal DateParseException(string message, DateParseErrorComponents errorComponents)
: base(message)
{
ErrorComponents = errorComponents;
}
