Not append new data to an array - swift

Question

I want to add new data to a list in my project
but I can't do it
I have a ContentView.swift view for showing products list
and in another view (ShopView) I want to add data to products array
My products array and my addProduct() function
in the Products.swift file
Please help me
Thanks
ContentView.swift
struct ContentView: View {
#ObservedObject var cart = Products()
var body: some View {
NavigationView{
List {
ForEach(cart.products) { product in
Text("\(product.name) \(product.price)$")
}
}
.navigationBarItems(
trailing: NavigationLink(destination: Shop()) {
Text("Go Shop")
})
.navigationBarTitle("Cart")
}
}
}
Product.swift
struct Product: Identifiable {
var id = UUID()
var name: String
var price: Int
}
Shop.swift
struct Shop: View {
#ObservedObject var cart = Products()
var body: some View {
VStack{
Button("Add Product To Cart") {
cart.addProduct(product: Product(name: "Name", price: 399))
}
}
}
}
Products.swift
class Products: ObservableObject {
#Published var products = [Product]()
func addProduct(product: Product) {
products.append(product)
print("Product Added")
}
}

Answer 1

Right now, you're creating two different instances of Products. If you want the data to be shared, you have to use the same instance.
struct ContentView: View {
#ObservedObject var cart = Products()
var body: some View {
NavigationView{
List {
ForEach(cart.products) { product in
Text("\(product.name) \(product.price)$")
}
}
.navigationBarItems(
trailing: NavigationLink(destination: Shop(cart: cart)) { //<-- HERE
Text("Go Shop")
})
.navigationBarTitle("Cart")
}
}
}
struct Shop: View {
#ObservedObject var cart : Products //<-- HERE
var body: some View {
VStack{
Button("Add Product To Cart") {
cart.addProduct(product: Product(name: "Name", price: 399))
}
}
}
}
Another way to achieve this type of functionality is by using an environment object. Additional reading on that approach: https://www.hackingwithswift.com/quick-start/swiftui/how-to-use-environmentobject-to-share-data-between-views

Answer 2

I think you will find the simplest implementation will be to define your model as:
class Products: ObservableObject {
//Implement a shared resource here
public static let shared = Products()
// I would also make the published var name something different then the class name.
// Otherwise you will be calling a lot of products.products.
// Or you could change the name of the class to "Cart"
#Published var products: [Product] = []
func addProduct(product: Product) {
products.append(product)
print("Product Added")
}
}
Use it in your structs with:
#ObservedObject var cart = Products.shared
This will give you one common shared Products class. You don't have to worry about passing is around between views.