Class with an Observable Object has been used by is not initializing-CodePudding

I've added an Observable Object to my class DetailViewModel, but I am getting an error "Class 'DetailViewModel' has no initializers". Can anyone explain why?

import Foundation
import UIKit

@MainActor
 class DetailViewModel: ObservableObject{
    
    @Published   var strMeal: String = ""
    @Published   var strInstructions: String
    @Published   var strIngredient: String
    @Published   var strMeasure: String
    @Published   var strMealThumb:URL?
    
    
     private func loadMealDetails(idMeal: String) async {
         do {
             let mealDetailResponse = try await  WebServiceRequest().loadData(url: Constants.Urls.getMealByIdUrl(strMeal)) { data in
              return try?   JSONDecoder().decode(MealDetailModel.self, from:data )
             }


         } catch {
               print(error)
         }
     }

CodePudding user response：

You have defined some properties (strInstructions, strIngredient, and strMeasure) that don't have initial values specified. Unlike structs, which get synthesized initializers (eg the compiler makes a initializer for us), with a class, we have to create an initializer ourselves (or give all of the properties default values).

With default values, it may look like:

@MainActor
class DetailViewModel: ObservableObject{
    
    @Published var strMeal: String = ""
    @Published var strInstructions: String = ""
    @Published var strIngredient: String = ""
    @Published var strMeasure: String = ""
    @Published var strMealThumb:URL?
    
}

Or, with an initializer, it could be something like:

@MainActor
class DetailViewModel: ObservableObject{
    
    @Published var strMeal: String = ""
    @Published var strInstructions: String
    @Published var strIngredient: String
    @Published var strMeasure: String
    @Published var strMealThumb:URL?
    
    init(strInstructions: String, strIngredient: String, strMeasure: String) {
        self.strInstructions = strInstructions
        self.strIngredient = strIngredient
        self.strMeasure = strMeasure
    }
}

You may also want to accept values for strMeal and strMealThumb in your initializer -- it's up to you.