👉 Overview
👀 What ?
iOS serialization and encoding is a process that assists in converting complex data structures into a format that can be easily stored or transmitted and then reconstructed later. In the context of iOS development, serialization is crucial for data persistence, interprocess communication, and for sending data over a network.
🧐 Why ?
Understanding iOS serialization and encoding is essential because it allows developers to save the state of their applications, share data between applications, or communicate with web services. It also plays an important role in ensuring the security of an application. Poorly implemented serialization can lead to several security issues such as information disclosure or data exfiltration.
⛏️ How ?
iOS provides several ways to perform serialization and encoding. You can use 'NSCoding', a simple and efficient way to encode and decode data. 'NSKeyedArchiver', a concrete subclass of NSCoder, provides a way to encode objects (and scalar values) into an architecture-independent format that can be stored in a file. When it's time to retrieve this data, you can use 'NSKeyedUnarchiver' to decode the data. You can also use 'Codable', a type alias for the 'Decodable' and 'Encodable' protocols, introduced in Swift 4. This protocol can be used to save data to disk as well as to send and receive data from a server in JSON format.
⏳ When ?
The use of serialization and encoding in iOS started with the introduction of the NSCoding protocol in iOS 2.0. The Codable protocol was introduced later in Swift 4 to simplify the process.
⚙️ Technical Explanations
At a deeper level, iOS serialization and encoding processes involve converting the in-memory objects into a byte stream (serialization), and then converting this byte stream back into in-memory objects (deserialization). The byte stream can be used to persist the object's state in a storage medium or transmit it over a network to a different process or device. This process is crucial in iOS development for data persistence and interprocess communication. When implemented correctly, it ensures the security of the application by preventing information disclosure or data exfiltration. However, it should be noted that proper error handling and validation are necessary during the deserialization process to prevent potential security issues.