Issue with unwrapping optionals in my model and DTO - ios

Question

This might be something really easy but I don't understand how to do it:
so I have this DTO struct I use to get API data into it and map it to Model struct
my DTO:
struct PetDTO: Codable {
var id: Int
var category: CategoryDTO?
var name: String?
var photoUrls: [String]?
var tags: [TagDTO]?
var status: StatusDTO?
}
public class CategoryDTO: NSObject, Codable {
var id: Int
var name: String?
private enum CodingKeys: String, CodingKey {
case id = "id"
case name = "name"
}
required public init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
id = try container.decode(Int.self, forKey: .id)
name = try container.decode(String.self, forKey: .name)
}
}
public class TagDTO: NSObject, Codable {
var id: Int
var name: String?
private enum CodingKeys: String, CodingKey {
case id = "id"
case name = "name"
}
required public init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
id = try container.decode(Int.self, forKey: .id)
name = try container.decode(String.self, forKey: .name)
}
}
enum StatusDTO: String, Codable {
case available
case sold
case pending
}
And my model:
struct PetDataModel {
var id: Int
var category: Category
var name: String?
var photoUrls: [String]?
var tags: [Tags]?
var status: Status?
init(petDto: PetDTO) {
self.id = petDto.id
self.category = Category(categoryDto: petDto.category)
self.name = petDto.name
self.photoUrls = petDto.photoUrls
for tag in petDto.tags ?? [] {
self.tags = [Tags(tagDTO: tag)] // petDto?.map { Tags(tagDTO: $0) }
}
self.status = Status(rawValue: petDto.status?.rawValue)
}
}
struct Category {
var id: Int
var name: String?
init(categoryDto: CategoryDTO) {
self.id = categoryDto.id
self.name = categoryDto.name
}
}
struct Tags {
var id: Int
var name: String?
init(tagDTO: TagDTO) {
self.id = tagDTO.id
self.name = tagDTO.name
}
}
enum Status: String, Codable {
case available
case sold
case pending
}
As you can see, the mapping happens in Init of PetDataModel. I have errors on this lines
Please tell me how to fix this without making CategoryDto from PetDTO non optional, I need it to stay optional.

Answer 1

You can make category form your PetDataModel optional too.
struct PetDataModel {
var id: Int
var category: Category?
var name: String?
var photoUrls: [String]?
var tags: [Tags]?
var status: Status?
init(petDto: PetDTO) {
self.id = petDto.id
self.category = Category(categoryDto: petDto.category)
self.name = petDto.name
self.photoUrls = petDto.photoUrls
for tag in petDto.tags ?? [] {
self.tags = [Tags(tagDTO: tag)] // petDto?.map { Tags(tagDTO: $0) }
}
self.status = Status(rawValue: petDto.status?.rawValue)
}
}
and make your initializer optional:
struct Category {
var id: Int
var name: String?
init?(categoryDto: CategoryDTO?) {
guard let categoryDto = categoryDto else{
return nil
}
self.id = categoryDto.id
self.name = categoryDto.name
}
}
if you don´t want an optional initializer you can check and assign like this:
self.category = petDto.category != nil ? Category(categoryDto: petDto.category!) : nil