Streamlining JSON Encoding and Decoding in Swift with Property Wrappers

As iOS developers, we frequently interact with various public and private REST APIs, some of which are reliable and well-established, while others may not be as reliable. In certain scenarios, we cannot guarantee that the received model will precisely match the expected type. Some APIs may return different types for the same property. For instance, we might anticipate a Double value, but the API could provide a String or a Double value instead.

The article shows how to effectively handle such situations by implementing init(from decoder: Decoder) throws functions for structures, which require manual decoding of all values. However, for larger structures, it becomes more challenging and preferable to rely on automatically synthesized init.

To leverage synthesized init and effectively handle different types simultaneously, the author introduces the concept of Property Wrappers in Swift. They create a property wrapper called LosslessStringCodable, which simplifies the encoding and decoding of JSON objects. This property wrapper is defined as a generic type that requires its underlying value to conform to both the LosslessStringConvertible and Codable protocols.

The article provides code examples that demonstrate how to use the LosslessStringCodable property wrapper for encoding and decoding JSON objects. It also includes an extension for KeyedDecodingContainer that includes a custom decoding function specifically designed for the LosslessStringCodable type.

Overall, this article is a valuable resource for iOS developers looking to streamline JSON encoding and decoding in Swift using Property Wrappers.