https://github.com/Flight-School/Codable-DIY-Kit

A template for creating your own Swift Codable encoders and decoders
https://github.com/Flight-School/Codable-DIY-Kit

codable decoder encoder swift

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A template for creating your own Swift Codable encoders and decoders

• Host: GitHub
• URL: https://github.com/Flight-School/Codable-DIY-Kit
• Owner: Flight-School
• License: mit
• Created: 2018-05-07T16:06:18.000Z (over 6 years ago)
• Default Branch: master
• Last Pushed: 2020-03-30T19:08:46.000Z (over 4 years ago)
• Last Synced: 2024-07-05T13:46:19.824Z (3 months ago)
• Topics: codable, decoder, encoder, swift
• Language: Swift
• Homepage: https://flight.school/books/codable
• Size: 12.7 KB
• Stars: 227
• Watchers: 4
• Forks: 10
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • Funding: .github/FUNDING.yml
  • License: LICENSE.md

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README

        
# DIY Codable Encoder / Decoder Kit

In Swift 4,

a type that conforms to the `Codable` protocol

can be encoded to or decoded from representations

for any format that implements a corresponding `Encoder` or `Decoder` type.

At the time of its release,

the only reference implementations for these types

were the Foundation framework's `JSONEncoder` / `JSONDecoder`

and `PropertyListEncoder` and `PropertyListDecoder`.

The [implementation details](https://github.com/apple/swift/blob/master/stdlib/public/SDK/Foundation/JSONEncoder.swift)

of these types, however,

are obfuscated by translation logic from

`JSONSerialization` and `PropertyListSerialization`.

This repository provides a template

that makes it easier for developers

to create encoders and decoders for custom formats.

The template includes stubbed placeholders for the required types and methods

as well as simple tests for encoding and decoding `Codable` types.

This general structure was used to implement a `Codable`-compatible

[encoder and decoder for the MessagePack format](https://github.com/flight-school/messagepack).

For more information about the design and implementation

of custom encoder and decoder types,

see Chapter 7 of

[Flight School Guide to Swift Codable](https://flight.school/books/codable).

## Usage

* Clone this repository

* Find all instances of the "<#Format#>" placeholder

  and replace with the name of your own format

* Replace the leading underscores in the

  `___Decoder.swift` and `___Encoder.swift` files,

  as well as the source files in the Tests directory

* Run the command `swift package generate-xcodeproj`

  in the root project directory

* Fill in the missing implementation accordingly

### Encoder Structure

```swift

public class <#Format#>Encoder {

    public func encode(_ value: T) throws -> Data

                        where T : Encodable

}

final class _<#Format#>Encoder: Encoder {

    final class SingleValueContainer: SingleValueEncodingContainer

    final class UnkeyedContainer: UnkeyedEncodingContainer

    final class KeyedContainer: KeyedEncodingContainerProtocol

            where Key: CodingKey

}

protocol <#Format#>EncodingContainer: class {}

```

### Decoder Structure

```swift

public class <#Format#>Decoder {

    public func decode(_ type: T.Type,

                          from data: Data) throws -> T

                        where T : Decodable

}

final class _<#Format#>Decoder: Decoder {

    final class SingleValueContainer: SingleValueDecodingContainer

    final class UnkeyedContainer: UnkeyedDecodingContainer

    final class KeyedContainer: KeyedContainer

            where Key: CodingKey

}

protocol <#Format#>DecodingContainer: class {}

```

## License

MIT

## Contact

Mattt ([@mattt](https://twitter.com/mattt))