Access Data from Firestore and Put it in SwiftUI EnvironmentObject - firebase

Question

I am trying to use Firestore and get the data from the Firestore and then put it in EnvironmentObject. But it is not working out. I tried different approaches each ended with different errors.
Here is my code:
class FirebaseManager: ObservableObject {
#Published var tweets: [Tweet] = []
private let db: Firestore = Firestore.firestore()
init() {
db.collection("tweets")
.addSnapshotListener { snapshot, error in
if let error {
print(error.localizedDescription)
return
}
let tweets = snapshot?.documents.compactMap({ document in
try? document.data(as: Tweet.self)
})
if let tweets {
DispatchQueue.main.async {
self.tweets = tweets
}
}
}
}
}
Then I try to call FirebaseManager in the code below:
struct HomeTimelineScreen: View {
#EnvironmentObject var appState: AppState
#StateObject private var firebaseManager = FirebaseManager()
private var cancellables = Set<AnyCancellable>()
init() {
// ERROR Escaping closure captures mutating 'self' parameter
firebaseManager.$tweets.sink { tweets in
appState.tweets = tweets
}
// ERROR/WARNING ObservableObject of type AppState found. A View.environmentObject(_:) for AppState may be missing as an ancestor of this view.
firebaseManager.$tweets.assign(to: \.appState.tweets, on: self)
.store(in: &cancellables)
}
The EnvironmentObject AppState is injected in the TwitterApp main file as shown below:
#main
struct TwitterAppApp: App {
#ObservedObject var coordinator = Coordinator()
init() {
FirebaseApp.configure()
}
var body: some Scene {
WindowGroup {
NavigationStack(path: $coordinator.path) {
LandingScreen()
.navigationDestination(for: Route.self) { route in
switch route {
case .login:
LoginScreen().appLogoToolbar()
case .register:
RegistrationScreen().appLogoToolbar()
case .home:
HomeScreen()
case .detail(let tweet):
TweetDetailsScreen(tweet: tweet)
}
}
}.environmentObject(coordinator)
.environmentObject(AppState())
}
}
}
AppState:
import Foundation
class AppState: ObservableObject {
#Published var tweets: [Tweet] = []
}
UPDATE: My biggest issue is on how to re-render the TweetDetailScreen since it is also using the TweetCellView.
struct TweetDetailsScreen: View {
let tweet: Tweet
var body: some View {
List {
TweetCellView(tweet: tweet)
ForEach(1...20, id: \.self) { index in
Text("\(index)")
}
}
}
}
I took your advice and added single source of truth FirebaseManager and now it works as I want it to be.
struct TweetDetailsScreen: View {
#EnvironmentObject var firebaseManager: FirebaseManager
let tweet: Tweet
var body: some View {
List {
if let tweet = firebaseManager.findByDocumentId(tweet.documentID ?? "") {
TweetCellView(tweet: tweet)
}
ForEach(1...20, id: \.self) { index in
Text("\(index)")
}
}
}
}
class FirebaseManager: ObservableObject {
#Published var tweets: [Tweet] = []
private let db: Firestore = Firestore.firestore()
init() {
db.collection("tweets")
.addSnapshotListener { snapshot, error in
if let error {
print(error.localizedDescription)
return
}
let tweets = snapshot?.documents.compactMap({ document in
try? document.data(as: Tweet.self)
})
if let tweets {
DispatchQueue.main.async {
self.tweets = tweets
}
}
}
}
func findByDocumentId(_ documentId: String) -> Tweet? {
guard let index = tweets.firstIndex(where: { $0.documentID == documentId }) else { return nil }
return tweets[index]
}
}