Reload body items once data from service layer loads in swiftUI - ios

Question

I'm new to the swiftUI, looking for a way to refresh view once service data retrieved. What I want is, once page loads, -or before page loads- I want to call fillUI function so I can retrieve parsed json data from service layer, with that data I want to refresh this code block so my foreach block works with data I have:
VStack(spacing:15 ) {
ScrollView(.horizontal) {
VStack {
ForEach(0..<5) { i in
MeetingCellView(meetingData: meetingListData?.get(at: i) )
.frame(width: 340, height: 150)
.padding(.horizontal)
}.frame(width: 350)
}
}.frame(width: 350)
}
In UIKit, i was able to solve these issues with a way like loading and retrieving all the data first, then showing the view itself with a data. For swiftUI what is the best approach to do that?
Here is the full code of my related view body. I had searched internet but couldn't find the one yet.
import SwiftUI
struct HomeView: View {
#State var username: String = ""
#State var meetingCode: String = ""
#State var data: GetUserDetailModel? = nil
#State var meetingListData: [Datum]? = nil
#State var requestLoaded = false
var body: some View {
ZStack{
VStack {
Image("home.background")
.resizable()
.frame(maxHeight: 338)
Spacer()
ZStack {
VStack {
RoundedRectangle(cornerRadius: 8)
.padding(.top, -20)
.foregroundColor(.white)
}
ScrollView(.vertical, showsIndicators: false)
{
//MARK: - ScrollView Start
VStack {
HStack(spacing: 13.0) {
NavigationLink(destination: CreateMeetingView()) {
ZStack {
RoundedRectangle(cornerRadius: 12)
.foregroundColor(Color(red: 0.935, green: 0.914, blue: 0.957))
VStack(spacing: 18) {
HStack {
Image("icon.camera")
Spacer()
}
HStack {
Text("New Meeting")
.foregroundColor(Color(red: 0.476, green: 0.228, blue: 0.701))
.font(.custom("inter-semibold", size: 15))
Spacer()
}
}.padding(.horizontal, 15)
}.frame(maxWidth: .infinity, idealHeight: 101)
.padding(.leading, 25)
}
NavigationLink(destination: Text("there"))
{
ZStack {
RoundedRectangle(cornerRadius: 12)
.foregroundColor(Color(red: 0.897, green: 0.939, blue: 0.978))
VStack(spacing: 18) {
HStack {
Image("icon.calendar")
Spacer()
}
HStack {
Text("Schedule Now")
.foregroundColor(Color(red: 0.038, green: 0.525, blue: 0.917))
.font(.custom("inter-semibold", size: 15))
Spacer()
}
}.padding(.horizontal, 15)
}.frame(maxWidth: .infinity, idealHeight: 101)
.padding(.trailing, 25)
}
}
}
VStack {
HStack {
Text("Upcoming Meetings")
.font(.custom("inter-semibold", size: 17))
.padding(.leading, 25)
Spacer()
}
ZStack {
VStack(spacing: 30) {
HStack {
Image("upcoming.calendar")
}
HStack {
Text("You do not have a upcoming meeting.")
.font(.custom("inter-regular", size: 15))
.foregroundColor(Color(red: 0.692, green: 0.692, blue: 0.692))
}
}.hidden()
.padding(.vertical, 46)
VStack(spacing:15 ) {
ScrollView(.horizontal) {
VStack {
ForEach(0..<5) { i in
MeetingCellView(meetingData: meetingListData?.get(at: i) )
.frame(width: 340, height: 150)
.padding(.horizontal)
}.frame(width: 350)
}
}.frame(width: 350)
}
}
.padding(.horizontal ,15)
}.padding(.top, 25)
.padding(.bottom, 100)
//MARK: ScrollView End
}
}
}.ignoresSafeArea()
VStack {
HStack {
Image("splash.logo")
.resizable()
.frame(maxWidth: 100, maxHeight: 20)
.padding(.leading, 24)
Spacer()
Image("icon.profile")
.padding(.trailing,25)
}
VStack(spacing: 10.0) {
HStack {
Text("Good Morning,")
.font(.custom("inter-semibold", size: 13))
.foregroundColor(.white)
Spacer()
}
HStack {
Text(username)
.font(.custom("inter-semibold", size: 22))
.foregroundColor(.white)
Spacer()
}
}.padding(.leading, 24)
ZStack {
Color.white
VStack(spacing: 10.0) {
HStack {
Text("Join Meeting")
.font(.custom("inter-semibold", size: 13))
Spacer()
}
HStack {
TextField("Enter meeting code", text: $meetingCode)
.font(.custom("inter-regular", size: 15))
.keyboardType(.numbersAndPunctuation)
}
}.padding(.horizontal, 15)
}
.cornerRadius(6)
.frame(maxWidth: .infinity, maxHeight: 75.0)
.padding(.horizontal, 25.0)
.padding(.top, 30)
Spacer()
}.hiddenNavigationBarStyle()
}
.onAppear(perform: fillUI)
}
func fillUI() {
username = data?.givenName ?? "error"
Network.meetingList {meetings in
//print(meetings)
meetingListData = meetings?.data
requestLoaded = true
}
}
}
struct HomeView_Previews: PreviewProvider {
static var previews: some View {
HomeView()
}
}

Answer 1

We use task(priority:_:) for that, .e.g
List {
ForEach(meetings) { meeting in
MeetingView(meeting: meeting)
}
}
.navigationTitle(loaded ? "Meetings" : "Loading...")
.task {
loaded = false
meetings = await Meeting.fetchAll()
loaded = true
}
Also your body is far too large and you have too many #State. Break it up into subviews and try to only have 1 or 2 #State per View.