ConcreteTypeConverter Explained

POCO DataSet uses a custom converter pattern named ConcreteTypeConverter to handle the serialization and deserialization of interfaces such as IDataSet, IDataTable, IDataRow, and IColumnMetadata. JSON serializers cannot directly instantiate interfaces, so the converter bridges the gap by mapping an interface type to a specific concrete implementation.

Purpose of ConcreteTypeConverter

• Allow interfaces to be used in the public API while still supporting JSON serialization.
• Ensure that deserialization creates the correct concrete POCO types.
• Avoid leaking concrete type details into the external contract.
• Provide a central place to control how specific interface types are mapped.

Typical Usage Pattern

The converter is typically registered in JsonSerializerOptions as follows (conceptually):

jsonSerializerOptions.Converters.Add(new ConcreteTypeConverter<IDataSet, DataSet>());
jsonSerializerOptions.Converters.Add(new ConcreteTypeConverter<IDataTable, DataTable>());
jsonSerializerOptions.Converters.Add(new ConcreteTypeConverter<IDataRow, DataRow>());
jsonSerializerOptions.Converters.Add(new ConcreteTypeConverter<IColumnMetadata, ColumnMetadata>());

How It Works Internally (Conceptual)

• When serializing, the converter treats the interface instance as its concrete type.
• When deserializing, the converter instructs the serializer to create the specified concrete type.
• After deserialization, the created instance is returned as the interface type expected by calling code.

Table of Content POCO DataSet Serialization and Deserialization