put observedObject in List - swiftui

Question

I get the data from my api and create a class for them. I can use swifyJSON to init them correctly. The problem is that when I put my observedObject in a List, it can only show correctly once. It will crashed after I changed the view. It's very strong because my other List with similar data struct can work.(this view is in a tabView) Is somebody know where my getAllNotification() should put view.onAppear() or List.onAppear()? Thanks!!
class ManagerNotification : Identifiable, ObservableObject{
#Published var id = UUID()
var notifyId : Int = 0
var requestId : Int = 0
var requestName: String = ""
var groupName : String = ""
// var imageName: String { return name }
init(jsonData:JSON) {
notifyId = jsonData["notifyId"].intValue
requestId = jsonData["requestId"].intValue
requestName = jsonData["requestName"].stringValue
groupName = jsonData["groupName"].stringValue
}
}
import SwiftUI
import SwiftyJSON
struct NotificationView: View {
var roles = ["userNotification", "managerNotification"]
#EnvironmentObject var userToken:UserToken
#State var show = false
#State private var selectedIndex = 0
#State var userNotifications : [UserNotification] = [UserNotification]()
#State var managerNotifications : [ManagerNotification] = [ManagerNotification]()
var body: some View {
VStack {
Picker(selection: $selectedIndex, label: Text(" ")) {
ForEach(0..<roles.count) { (index) in
Text(self.roles[index])
}
}
.pickerStyle(SegmentedPickerStyle())
containedView()
Spacer()
}
.onAppear(perform: getAllNotification)
}
func containedView() -> AnyView {
switch selectedIndex {
case 0:
return AnyView(
List(userNotifications) { userNotification in
UserNotificationCellView(userNotification: userNotification)
}
)
case 1:
return AnyView(
List(managerNotifications) { managernotification in
ManagerNotificationCellView(managerNotification : managernotification)
}
.onAppear(perform: getManagerNotification)
)
default:
return AnyView(Text("22").padding(40))
}
}
func getAllNotification(){
// if (self.userNotifications.count != 0){
// self.userNotifications.removeAll()
// }
// I think the crash was in here, because when i don't use removeAll().
// It works fine, but i don't want every times i change to this view. my array will be longer and
// longer
if (self.managerNotifications.count != 0){
self.managerNotifications.removeAll()
}
NetWorkController.sharedInstance.connectApiByPost(api: "/User/email", params: ["token": "\(self.userToken.token)"])
{(jsonData) in
if let result = jsonData["msg"].string{
print("eeee: \(result)")
if(result == "you dont have any email"){
}else if(result == "success get email"){
if let searchResults = jsonData["mail"].array {
for notification in searchResults {
self.userNotifications.append(UserNotification(jsonData: notification))
}
}
}
}
}
NetWorkController.sharedInstance.connectApiByPost(api: "/Manager/email", params: ["token": "\(self.userToken.token)"])
{(jsonData) in
if let result = jsonData["msg"].string{
print("eeee: \(result)")
if(result == "you dont have any email"){
}else if(result == "success get email"){
if let searchResults = jsonData["mail"].array {
for notification in searchResults {
self.managerNotifications.append(ManagerNotification(jsonData: notification))
}
}
}
}
}
}
func getManagerNotification(){
// if (self.managerNotifications.count != 0){
// self.managerNotifications.removeAll()
// }
print(self.managerNotifications.count)
NetWorkController.sharedInstance.connectApiByPost(api: "/Manager/email", params: ["token": "\(self.userToken.token)"])
{(jsonData) in
if let result = jsonData["msg"].string{
print("eeee: \(result)")
if(result == "you dont have any email"){
}else if(result == "success get email"){
if let searchResults = jsonData["mail"].array {
for notification in searchResults {
self.managerNotifications.append(ManagerNotification(jsonData: notification))
}
}
}
}
}
}
}
error message
Warning once only: UITableView was told to layout its visible cells and other contents without being in the view hierarchy (the table view or one of its superviews has not been added to a window). This may cause bugs by forcing views inside the table view to load and perform layout without accurate information (e.g. table view bounds, trait collection, layout margins, safe area insets, etc), and will also cause unnecessary performance overhead due to extra layout passes. Make a symbolic breakpoint at UITableViewAlertForLayoutOutsideViewHierarchy to catch this in the debugger and see what caused this to occur, so you can avoid this action altogether if possible, or defer it until the table view has been added to a window. reason: 'attempt to delete section 0, but there are only 0 sections before the update'

Answer 1

I think you are confused about the role of #State and #ObservebableObject; it's not like MVC where you replace the ViewController with a SwiftUI.View as it appears you are trying to do in your example. Instead the view should be a function of either some local #State and/or an external #ObservedObject. This is closer to MVVM where your #ObservedObject is analogous to the ViewModel and the view will rebuild itself in response to changes in the #Published properties on the ObservableObject.
TLDR: move your fetching logic to an ObservableObject and use #Published to allow the view to subscribe to the results. I have an example here: https://github.com/joshuajhomann/TVMaze-SwiftUI-Navigation