// public methods
/// <summary>
/// Gets the actual type of an object by reading the discriminator from a BsonReader.
/// </summary>
/// <param name="bsonReader">The reader.</param>
/// <param name="nominalType">The nominal type.</param>
/// <returns>The actual type.</returns>
public Type GetActualType(IBsonReader bsonReader, Type nominalType)
{
// the BsonReader is sitting at the value whose actual type needs to be found
var bsonType = bsonReader.GetCurrentBsonType();
if (bsonType == BsonType.Document)
{
// ensure KnownTypes of nominalType are registered (so IsTypeDiscriminated returns correct answer)
BsonSerializer.EnsureKnownTypesAreRegistered(nominalType);
// we can skip looking for a discriminator if nominalType has no discriminated sub types
if (BsonSerializer.IsTypeDiscriminated(nominalType))
{
var bookmark = bsonReader.GetBookmark();
bsonReader.ReadStartDocument();
var actualType = nominalType;
if (bsonReader.FindElement(_elementName))
{
var context = BsonDeserializationContext.CreateRoot <BsonValue>(bsonReader);
var discriminator = BsonValueSerializer.Instance.Deserialize(context);
if (discriminator.IsBsonArray)
{
discriminator = discriminator.AsBsonArray.Last(); // last item is leaf class discriminator
}
actualType = BsonSerializer.LookupActualType(nominalType, discriminator);
}
bsonReader.ReturnToBookmark(bookmark);
return(actualType);
}
}
return(nominalType);
}
// public methods
/// <summary>
/// Gets the actual type of an object by reading the discriminator from a BsonReader.
/// </summary>
/// <param name="bsonReader">The reader.</param>
/// <param name="nominalType">The nominal type.</param>
/// <returns>The actual type.</returns>
public Type GetActualType(BsonReader bsonReader, Type nominalType)
{
// the BsonReader is sitting at the value whose actual type needs to be found
var bsonType = bsonReader.GetCurrentBsonType();
if (bsonReader.State == BsonReaderState.Value)
{
Type primitiveType = null;
switch (bsonType)
{
case BsonType.Boolean: primitiveType = typeof(bool); break;
case BsonType.Binary:
var bookmark = bsonReader.GetBookmark();
var binaryData = bsonReader.ReadBinaryData();
var subType = binaryData.SubType;
if (subType == BsonBinarySubType.UuidStandard || subType == BsonBinarySubType.UuidLegacy)
{
primitiveType = typeof(Guid);
}
bsonReader.ReturnToBookmark(bookmark);
break;
case BsonType.DateTime: primitiveType = typeof(DateTime); break;
case BsonType.Double: primitiveType = typeof(double); break;
case BsonType.Int32: primitiveType = typeof(int); break;
case BsonType.Int64: primitiveType = typeof(long); break;
case BsonType.ObjectId: primitiveType = typeof(ObjectId); break;
case BsonType.String: primitiveType = typeof(string); break;
}
// Type.IsAssignableFrom is extremely expensive, always perform a direct type check before calling Type.IsAssignableFrom
if (primitiveType != null && (primitiveType == nominalType || nominalType.IsAssignableFrom(primitiveType)))
{
return(primitiveType);
}
}
if (bsonType == BsonType.Document)
{
// ensure KnownTypes of nominalType are registered (so IsTypeDiscriminated returns correct answer)
BsonSerializer.EnsureKnownTypesAreRegistered(nominalType);
// we can skip looking for a discriminator if nominalType has no discriminated sub types
if (BsonSerializer.IsTypeDiscriminated(nominalType))
{
var bookmark = bsonReader.GetBookmark();
bsonReader.ReadStartDocument();
var actualType = nominalType;
if (bsonReader.FindElement(_elementName))
{
var discriminator = (BsonValue)BsonValueSerializer.Instance.Deserialize(bsonReader, typeof(BsonValue), null);
if (discriminator.IsBsonArray)
{
discriminator = discriminator.AsBsonArray.Last(); // last item is leaf class discriminator
}
actualType = BsonSerializer.LookupActualType(nominalType, discriminator);
}
bsonReader.ReturnToBookmark(bookmark);
return(actualType);
}
}
return(nominalType);
}
