/// <summary>Checks whether a type is nullable.</summary>
/// <param name="contextualType">The type.</param>
/// <param name="defaultReferenceTypeNullHandling">The default reference type null handling used when no nullability information is available.</param>
/// <returns>true if the type can be null.</returns>
public virtual bool IsNullable(ContextualType contextualType, ReferenceTypeNullHandling defaultReferenceTypeNullHandling)
{
var jsonPropertyAttribute = contextualType.GetContextAttribute <JsonPropertyAttribute>();
if (jsonPropertyAttribute != null && jsonPropertyAttribute.Required == Required.DisallowNull)
{
return(false);
}
if (contextualType.ContextAttributes.FirstAssignableToTypeNameOrDefault("NotNullAttribute", TypeNameStyle.Name) != null)
{
return(false);
}
if (contextualType.ContextAttributes.FirstAssignableToTypeNameOrDefault("CanBeNullAttribute", TypeNameStyle.Name) != null)
{
return(true);
}
if (contextualType.Nullability != Nullability.Unknown)
{
return(contextualType.Nullability == Nullability.Nullable);
}
var isValueType = contextualType.Type != typeof(string) &&
contextualType.TypeInfo.IsValueType;
return(isValueType == false &&
defaultReferenceTypeNullHandling != ReferenceTypeNullHandling.NotNull);
}
public override bool IsNullable(ContextualType contextualType, ReferenceTypeNullHandling defaultReferenceTypeNullHandling)
{
if (contextualType.GetContextAttribute <AlwaysPresentAttribute>() != null)
{
return(false);
}
return(base.IsNullable(contextualType, defaultReferenceTypeNullHandling));
}
/// <summary> /// Extracts the tuple element names if provided. /// </summary> /// <param name="contextualType">The contextual type for a ValueTuple type.</param> /// <returns>Returns the tuple element names or null.</returns> public static IList <String?>?GetTupleElementNames(this ContextualType contextualType) => contextualType.GetContextAttribute <TupleElementNamesAttribute>()?.TransformNames;