/// <summary>
/// Attempts to convert the values in <paramref name="result"/> to the specified type.
/// </summary>
/// <typeparam name="T">The <see cref="Type"/> for conversion.</typeparam>
/// <param name="result">The <see cref="ValueProviderResult"/>.</param>
/// <returns>
/// The converted value, or the default value of <typeparamref name="T"/> if the value could not be converted.
/// </returns>
public static T ConvertTo <T>(this ValueProviderResult result)
{
object valueToConvert = null;
if (result.Values.Count == 1)
{
valueToConvert = result.Values[0];
}
else if (result.Values.Count > 1)
{
valueToConvert = result.Values.ToArray();
}
return(ModelBindingHelper.ConvertTo <T>(valueToConvert, result.Culture));
}
/// <summary>
/// Attempts to convert the values in <paramref name="result"/> to the specified type.
/// </summary>
/// <param name="result">The <see cref="ValueProviderResult"/>.</param>
/// <param name="type">The <see cref="Type"/> for conversion.</param>
/// <returns>
/// The converted value, or the default value of <paramref name="type"/> if the value could not be converted.
/// </returns>
public static object ConvertTo(this ValueProviderResult result, Type type)
{
if (type == null)
{
throw new ArgumentNullException(nameof(type));
}
object valueToConvert = null;
if (result.Values.Count == 1)
{
valueToConvert = result.Values[0];
}
else if (result.Values.Count > 1)
{
valueToConvert = result.Values.ToArray();
}
return(ModelBindingHelper.ConvertTo(valueToConvert, type, result.Culture));
}
/// <inheritdoc />
public override async Task BindModelAsync(ModelBindingContext bindingContext)
{
if (bindingContext == null)
{
throw new ArgumentNullException(nameof(bindingContext));
}
await base.BindModelAsync(bindingContext);
if (bindingContext.Result == null || !bindingContext.Result.Value.IsModelSet)
{
// No match for the prefix at all.
return;
}
var result = bindingContext.Result.Value;
Debug.Assert(result.Model != null);
var model = (IDictionary <TKey, TValue>)result.Model;
if (model.Count != 0)
{
// ICollection<KeyValuePair<TKey, TValue>> approach was successful.
return;
}
var enumerableValueProvider = bindingContext.ValueProvider as IEnumerableValueProvider;
if (enumerableValueProvider == null)
{
// No IEnumerableValueProvider available for the fallback approach. For example the user may have
// replaced the ValueProvider with something other than a CompositeValueProvider.
return;
}
// Attempt to bind dictionary from a set of prefix[key]=value entries. Get the short and long keys first.
var keys = enumerableValueProvider.GetKeysFromPrefix(bindingContext.ModelName);
if (!keys.Any())
{
// No entries with the expected keys.
return;
}
// Update the existing successful but empty ModelBindingResult.
var metadataProvider = bindingContext.OperationBindingContext.MetadataProvider;
var valueMetadata = metadataProvider.GetMetadataForType(typeof(TValue));
var modelBinder = bindingContext.OperationBindingContext.ModelBinder;
var keyMappings = new Dictionary <string, TKey>(StringComparer.Ordinal);
foreach (var kvp in keys)
{
// Use InvariantCulture to convert the key since ExpressionHelper.GetExpressionText() would use
// that culture when rendering a form.
var convertedKey = ModelBindingHelper.ConvertTo <TKey>(kvp.Key, culture: null);
using (bindingContext.EnterNestedScope(
modelMetadata: valueMetadata,
fieldName: bindingContext.FieldName,
modelName: kvp.Value,
model: null))
{
await modelBinder.BindModelAsync(bindingContext);
var valueResult = bindingContext.Result;
// Always add an entry to the dictionary but validate only if binding was successful.
model[convertedKey] = ModelBindingHelper.CastOrDefault <TValue>(valueResult.Value.Model);
keyMappings.Add(kvp.Key, convertedKey);
}
}
bindingContext.ValidationState.Add(model, new ValidationStateEntry()
{
Strategy = new ShortFormDictionaryValidationStrategy <TKey, TValue>(keyMappings, valueMetadata),
});
}
