/// <summary>
/// Attempts to bind the model using formatters.
/// </summary>
/// <param name="bindingContext">The <see cref="ModelBindingContext"/>.</param>
/// <returns>
/// A <see cref="Task{ModelBindingResult}"/> which when completed returns a <see cref="ModelBindingResult"/>.
/// </returns>
private async Task <ModelBindingResult> BindModelCoreAsync(ModelBindingContext bindingContext)
{
if (bindingContext == null)
{
throw new ArgumentNullException(nameof(bindingContext));
}
// For compatibility with MVC 5.0 for top level object we want to consider an empty key instead of
// the parameter name/a custom name. In all other cases (like when binding body to a property) we
// consider the entire ModelName as a prefix.
var modelBindingKey = bindingContext.IsTopLevelObject ? string.Empty : bindingContext.ModelName;
var httpContext = bindingContext.OperationBindingContext.HttpContext;
var formatterContext = new InputFormatterContext(
httpContext,
modelBindingKey,
bindingContext.ModelState,
bindingContext.ModelMetadata,
_readerFactory);
var formatters = bindingContext.OperationBindingContext.InputFormatters;
var formatter = formatters.FirstOrDefault(f => f.CanRead(formatterContext));
if (formatter == null)
{
var unsupportedContentType = Resources.FormatUnsupportedContentType(
bindingContext.OperationBindingContext.HttpContext.Request.ContentType);
bindingContext.ModelState.AddModelError(modelBindingKey, unsupportedContentType);
// This model binder is the only handler for the Body binding source and it cannot run twice. Always
// tell the model binding system to skip other model binders and never to fall back i.e. indicate a
// fatal error.
return(ModelBindingResult.Failed(modelBindingKey));
}
try
{
var previousCount = bindingContext.ModelState.ErrorCount;
var result = await formatter.ReadAsync(formatterContext);
var model = result.Model;
// Ensure a "modelBindingKey" entry exists whether or not formatting was successful.
bindingContext.ModelState.SetModelValue(modelBindingKey, rawValue: model, attemptedValue: null);
if (result.HasError)
{
// Formatter encountered an error. Do not use the model it returned. As above, tell the model
// binding system to skip other model binders and never to fall back.
return(ModelBindingResult.Failed(modelBindingKey));
}
return(ModelBindingResult.Success(modelBindingKey, model));
}
catch (Exception ex)
{
bindingContext.ModelState.AddModelError(modelBindingKey, ex, bindingContext.ModelMetadata);
// This model binder is the only handler for the Body binding source and it cannot run twice. Always
// tell the model binding system to skip other model binders and never to fall back i.e. indicate a
// fatal error.
return(ModelBindingResult.Failed(modelBindingKey));
}
}
/// <inheritdoc />
public virtual async Task <ModelBindingResult> BindModelAsync([NotNull] ModelBindingContext bindingContext)
{
ModelBindingHelper.ValidateBindingContext(bindingContext);
var model = bindingContext.Model;
if (!bindingContext.ValueProvider.ContainsPrefix(bindingContext.ModelName))
{
// If we failed to find data for a top-level model, then generate a
// default 'empty' model (or use existing Model) and return it.
if (bindingContext.IsTopLevelObject)
{
if (model == null)
{
model = CreateEmptyCollection(bindingContext.ModelType);
}
return(ModelBindingResult.Success(bindingContext.ModelName, model));
}
return(ModelBindingResult.NoResult);
}
var valueProviderResult = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
CollectionResult result;
if (valueProviderResult == ValueProviderResult.None)
{
result = await BindComplexCollection(bindingContext);
}
else
{
result = await BindSimpleCollection(bindingContext, valueProviderResult);
}
var boundCollection = result.Model;
if (model == null)
{
model = ConvertToCollectionType(bindingContext.ModelType, boundCollection);
}
else
{
// Special case for TryUpdateModelAsync(collection, ...) scenarios. Model is null in all other cases.
CopyToModel(model, boundCollection);
}
Debug.Assert(model != null);
if (result.ValidationStrategy != null)
{
bindingContext.ValidationState.Add(model, new ValidationStateEntry()
{
Strategy = result.ValidationStrategy,
});
}
if (valueProviderResult != ValueProviderResult.None)
{
// If we did simple binding, then modelstate should be updated to reflect what we bound for ModelName.
// If we did complex binding, there will already be an entry for each index.
bindingContext.ModelState.SetModelValue(
bindingContext.ModelName,
valueProviderResult);
}
return(ModelBindingResult.Success(bindingContext.ModelName, model));
}
