How to override [CodingKey] to an Encoder or Decoder?

In Swift, the codingPath property is used to keep track of the coding keys as you encode or decode data using the Encoder and Decoder protocols. Typically, this property is managed automatically when you use a KeyedEncodingContainer or KeyedDecodingContainer with a struct or class that conforms to the Codable protocol. However, if you have a custom coding class and want to provide your own codingPath, you can do so.

Here's how you can override the codingPath property in your custom coding class:

import Foundation

class MyCustomEncoder: Encoder {
    // Your custom implementation here

    var codingPath: [CodingKey] = [] // Initialize the codingPath

    // Rest of your Encoder implementation...
}

In this example, I've created a custom encoder class MyCustomEncoder that conforms to the Encoder protocol. Within this class, I've added a property codingPath and initialized it as an empty array of CodingKey. You can manipulate this array to represent the coding path as you encode data.

For example, when encoding a nested container, you can push a new coding key onto the coding path, and when you exit the nested container, you can pop it off:

struct MyCustomEncodingContainer: EncodingContainer {
    // Your custom implementation here

    mutating func encode(_ value: Bool, forKey key: KeyedEncodingContainer<K>.Key) throws {
        // Add the current key to the coding path
        codingPath.append(key)

        // Encode your value here...

        // Remove the current key from the coding path when done
        codingPath.removeLast()
    }
    
    // Rest of your EncodingContainer implementation...
}

In this way, you can manage the codingPath property manually within your custom coding class to track the hierarchy of coding keys as you encode or decode data.

Remember that managing the codingPath manually can be error-prone, so it's essential to handle it carefully to ensure the correct encoding or decoding of your data.