EntryDecodable

Decodable is a powerful Swift standard library feature that developers can use to decode custom types from external representation, such as JSON.

EntryDecodable is an extension of the decodable protocol that you can use to decode the response to a specific model. By using this protocol, you can define types that will be mapped from your entries of the content type.

In this guide, we will discuss how we can use the EntryDecodable Protocol in your Swift SDK.

EntryDecodable Example Usage

Let’s understand how to use this protocol with the help of a few examples.

Standard Usage

We have a content type named Session and to fetch entries of our Session content type from the Swift SDK, we need to create a class named Session that implements the EntryDecodable protocol as follows:

Example usage:

class Session: EntryDecodable {

public enum FieldKeys: String, CodingKey {

     case title, uid, locale, type, speakers

     case createdAt = "created_at"

     case updatedAt = "updated_at"

     case createdBy = "created_by"

     case updatedBy = "updated_by"

     case sessionId = "session_id"

     case desc = "description"

     case sessionTime = "session_time"

 }

 var locale: String

 var title: String

 var uid: String

 var createdAt: Date?

 var updatedAt: Date?

 var createdBy: String?

 var updatedBy: String?

 var sessionId: Int

 var desc: String

 var type: String

 var sessionTime: SessionTime

 var speakers: [Speaker]?

 public required init(from decoder: Decoder) throws {

     let container   = try decoder.container(keyedBy: FieldKeys.self)

     uid = try container.decode(String.self, forKey: .uid)

     title = try container.decode(String.self, forKey: .title)

     createdBy = try? container.decode(String.self, forKey: .createdBy)

     updatedBy = try? container.decode(String.self, forKey: .updatedBy)

     createdAt = try? container.decode(Date.self, forKey: .createdAt)

     updatedAt = try? container.decode(Date.self, forKey: .updatedAt)

     locale = try container.decode(String.self, forKey: .locale)

     sessionId = try container.decode(Int.self, forKey: .sessionId)

     desc = try container.decode(String.self, forKey: .desc)

     type = try container.decode(String.self, forKey: .type)

     sessionTime = try container.decode(DateTime.self, forKey: .sessionTime)

     speakers = try container.decode([Speaker].self, forKey: .speakers)

  }

}

Usage in Referencing

Let’s say there is another content type in our Stack named Speaker that is referenced in our Session Content Type.

For this case, we will create a class named Speaker that implements the EntryDecodable protocol as follows: Example usage:

class Speaker: EntryDecodable {

  public enum FieldKeys: String, CodingKey {

    case createdAt = "created_at"

    case updatedAt = "updated_at"

    case createdBy = "created_by"

    case updatedBy = "updated_by"

    case desc = "description"

  }


  var locale: String

  var title: String

  var uid: String

  var createdAt: Date?

  var updatedAt: Date?

  var createdBy: String?

  var updatedBy: String?

  var sessionId: Int

  var desc: String

  var name: String

  public required init(from decoder: Decoder) throws {

    let container = try decoder.container(keyedBy: FieldKeys.self)

    uid = try container.decode(String.self, forKey: .uid)

    title = try container.decode(String.self, forKey: .title)

    createdBy = try? container.decode(String.self, forKey: .createdBy)

    updatedBy = try? container.decode(String.self, forKey: .updatedBy)

    createdAt = try? container.decode(Date.self, forKey: .createdAt)

    updatedAt = try? container.decode(Date.self, forKey: .updatedAt)

    locale = try container.decode(String.self, forKey: .locale)

    name = try container.decode(String.self, forKey: .name)

    desc = try container.decode(String.self, forKey: .desc)

  }

}

In the Session class, we have a ‘session_time’ Global Field. To parse it, we need to create a class named SessionTime that implements the Decodable protocol as follows.

Example:

class SessionTime: Decodable {

  var startTime: Date?

  var endTime: Date?


  public enum CodingKeys: String, CodingKey {

    case startTime = "start_time"

    case endTime = "end_time"

  }

  public required init(from decoder: Decoder) throws {

    let container = try decoder.container(keyedBy: CodingKeys.self)

    startTime = try? container.decode(Date.self, forKey: .startTime)

    endTime = try? container.decode(Date.self, forKey: .endTime)

  }

}

NoteIf we have fields with Modular block, JSON, or an array of JSON in our content type, we can create a class that implements Decodable.

Name	Type	Description
FieldKeys	CodingKey	The CodingKey representing the field identifiers/JSON keys for the corresponding content type. These coding keys should be the same as those used when implementing Decodable.