How to update one view from within another in SwiftUI - mvvm

Question

I am working on a SwiftUI view where I have it populates other subviews within the main view. My question is how can I call something in the main view from within a sub view?
Here is what the code looks like for my main view:
struct MovieList: View {
#ObservedObject var viewModel = MovieViewModel()
var body: some View {
VStack {
ScrollView(.vertical) {
VStack {
ForEach(self.viewModel.movie) { movie in
MovieView(movie: movie)
}
}
}
}
.navigationBarTitle("Movies")
.onAppear {
self.viewModel.fetchMovies() // Fetch all movies and cause entire view to refresh and populate movies
}
}
}
This main view populates a list of movies by adding multiple MovieView instances.
Here is some example code for the MovieView:
struct MovieView: View {
let movie: Movie
var body: some View {
VStack(alignment: .leading) {
HStack {
Text(“Movie Title: \(movie.title)”)
}.padding([.top, .leading, .bottom])
Button("Do not show this movie") {
// Update user prefers to hide the movie.
// But also somehow from within here call viewModel.fetchMovies() in the other view to refresh the movies list
}
}
}
}
So for example, from within one of the MovieView views, how can I have fetchMovies() from within the main view called so that everything gets updated?
Essentially a list of items is being populated and I would like for any one of these to have the ability to refresh/ perform some action on the entire main view

Answer 1

In terms of updating the Movie itself, as was pointed out in the comments, you probably want to pass a Binding to it. See the changes to the ForEach.
In terms of calling fetchMovies again, you can either pass the entire ObservableObject to the child view or just pass a reference to the function you need (which I've shown below):
struct Movie : Identifiable {
var id = UUID()
var title : String
var isHidden: Bool
}
class MovieViewModel : ObservableObject {
#Published var movies = [Movie]()
func fetchMovies() {
//fetch
}
}
struct MovieList: View {
#ObservedObject var viewModel = MovieViewModel()
var body: some View {
VStack {
ScrollView(.vertical) {
VStack {
ForEach($viewModel.movies) { $movie in
MovieView(movie: $movie, fetchMovies: viewModel.fetchMovies)
}
}
}
}
.navigationBarTitle("Movies")
.onAppear {
self.viewModel.fetchMovies()
}
}
}
struct MovieView: View {
#Binding var movie: Movie
var fetchMovies : () -> Void
var body: some View {
VStack(alignment: .leading) {
HStack {
Text("Movie Title: \(movie.title)")
}.padding([.top, .leading, .bottom])
Button("Do not show this movie") {
movie.isHidden = true
fetchMovies()
}
}
}
}