Codable in SwiftUI

Codable in SwiftUI

Codable protocol is so that we can decode and encode our data. When we download data from the Internet it doesn’t come in a data form that we can actually use

We need to decode that data into the data structure that we have in our App. Here are how to decode data from json data on the Internet to data that we can use in our app and then the reverse we can take the data in our app and we can encode it to send it back out to the Internet as json data

import SwiftUI

// Codable = Decodable + Encodable

// MARK: -  MODEL
struct CustomerModel: Identifiable, Codable {
	let id: String
	let name: String
	let points: Int
	let isPremium: Bool

	// Using Codable protocol, doesn't need to boiler code below

	// enum CodingKeys: String, CodingKey {
	// 	case id
	// 	case name
	// 	case points
	// 	case isPremium
	// }
	//
	// init(id: String, name: String, points: Int, ispremium: Bool) {
	// 	self.id = id
	// 	self.name = name
	// 	self.points = points
	// 	self.isPremium = ispremium
	// }
	//
	// init(from decoder: Decoder) throws {
	// 	let container = try decoder.container(keyedBy: CodingKeys.self)
	// 	self.id = try container.decode(String.self, forKey: .id)
	// 	self.name = try container.decode(String.self, forKey: .name)
	// 	self.points = try container.decode(Int.self, forKey: .points)
	// 	self.isPremium = try container.decode(Bool.self, forKey: .isPremium)
	// }
	//
	// // Encode function
	// func encode(to encoder: Encoder) throws {
	// 	var container = encoder.container(keyedBy: CodingKeys.self)
	// 	try container.encode(id, forKey: .id)
	// 	try container.encode(name, forKey: .name)
	// 	try container.encode(points, forKey: .points)
	// 	try container.encode(isPremium, forKey: .isPremium)
	// }
}

// MARK: -  VIEWMODEL
class CodableViewModel: ObservableObject {
	// MARK: -  PROPERTY
	@Published var customer: CustomerModel? = nil
	// MARK: -  INIT
	init() {
		getData()
	}
	// MARK: -  FUNCTION
	func getData() {
		guard let data = getJsonData() else { return }

		// manually decode data

		// if
		// 	let localData = try? JSONSerialization.jsonObject(with: data, options: []),
		// 	let dictonary = localData as? [String:Any],
		// 	let id = dictonary["id"] as? String,
		// 	let name = dictonary["name"] as? String,
		// 	let points = dictonary["points"] as? Int,
		// 	let isPremium = dictonary["isPremium"] as? Bool {
		//
		// 	let newCustomer = CustomerModel(id: id, name: name, points: points, isPremium: isPremium)
		// 	customer = newCustomer
		// }

		// Using decode protocol

		// do {
		// 	self.customer = try JSONDecoder().decode(CustomerModel.self, from: data)
		// } catch let error {
		// 	print("Error decoding. \(error)")
		// }

		// short one line from do catch
		self.customer = try? JSONDecoder().decode(CustomerModel.self, from: data)
	}
	func getJsonData()-> Data? {

		let customer = CustomerModel(id: "111", name: "Emma", points: 100, isPremium: false)
		let jsonData = try? JSONEncoder().encode(customer)

		// let dictionary: [String:Any] = [
		// 	"id" : "12345",
		// 	"name" : "Jacob",
		// 	"points" : 5,
		// 	"isPremium" : true
		// ]
		//
		// let jsonData = try? JSONSerialization.data(withJSONObject: dictionary, options: [])
		return jsonData
	}
}

struct CodableBootCamp: View {
// MARK: -  PROPERTY
@StateObject var vm = CodableViewModel()
// MARK: -  BODY
var body: some View {
VStack (spacing: 20) {
  if let customer = vm.customer {
    Text(customer.id)
    Text(customer.name)
    Text("\(customer.points)")
    Text(customer.isPremium.description)
  }
} //: VSTACK
}
}

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🗃 Reference

SwiftUI Thinking - https://www.youtube.com/watch?v=H9mt8WjpZgM&list=PLwvDm4VfkdpiagxAXCT33Rkwnc5IVhTar&index=27