SWIFTUI Observable Object Data Task only runs once? - swift

Question

I have an observable object class that downloads an image from a url to display:
class ImageLoader : ObservableObject {
var didChange = PassthroughSubject<Data, Never>()
var data = Data() {
didSet {
didChange.send(data)
}
}
init(urlString:String){
guard let url = URL(string: urlString) else {return}
let task = URLSession.shared.dataTask(with: url) { data, response, error in
guard let data = data else { return }
DispatchQueue.main.async {
self.data = data
print("imageloader1")
}
}
task.resume()
}
and I show it using:
struct ShowImage1: View {
#ObservedObject var imageLoader:ImageLoader
#State var image:UIImage = UIImage()
init(withURL url:String) {
imageLoader = ImageLoader(urlString:url)
}
var body: some View {
Image(uiImage: image)
.resizable()
.aspectRatio(contentMode: .fit)
.edgesIgnoringSafeArea(.top)
.onReceive(imageLoader.didChange) {
data in self.image = UIImage(data: data) ?? UIImage()
}
}
The problem I'm having is this is only capable of running once, If i click off the ShowImage1 view and then click back on to it, ImageLoader doesn't run again, and I'm left with a blank page.
How can I ensure that ImageLoader Runs every time the ShowImage1 view is accessed?
EDIT:
I access ShowImage1 like this:
struct PostCallForm: View {
var body: some View {
NavigationView {
Form {
Section {
Button(action: {
if true {
self.showImage1 = true
}
}){
Text("View Camera 1 Snapshot")
}.overlay(NavigationLink(destination: ShowImage1(withURL: "example.com/1.jpg"), isActive: self.$showImage1, label: {
EmptyView()
}))
}
}
Section {
Button(action: {
}){
Text("Submit")
}
}
}.disabled(!submission.isValid)
}
}
}

Answer 1

import SwiftUI
import Combine
class ImageLoader : ObservableObject {
var didChange = PassthroughSubject<Data, Never>()
var data = Data() {
didSet {
didChange.send(data)
}
}
func loadImage(urlString:String) {
guard let url = URL(string: urlString) else {return}
let task = URLSession.shared.dataTask(with: url) { data, response, error in
guard let data = data else { return }
DispatchQueue.main.async {
self.data = data
print("imageloader1")
}
}
task.resume()
}
}
struct ShowImage1Parent: View {
#State var url: String = ""
var sampleURLs: [String] = ["https://image.shutterstock.com/image-vector/click-here-stamp-square-grunge-600w-1510095275.jpg", "https://image.shutterstock.com/image-vector/certified-rubber-stamp-red-grunge-600w-1423389728.jpg", "https://image.shutterstock.com/image-vector/sample-stamp-square-grunge-sign-600w-1474408826.jpg" ]
var body: some View {
VStack{
Button("load-image", action: {
url = sampleURLs.randomElement()!
})
ShowImage1(url: $url)
}
}
}
struct ShowImage1: View {
#StateObject var imageLoader:ImageLoader = ImageLoader()
#State var image:UIImage = UIImage()
#Binding var url: String
var body: some View {
VStack{
Image(uiImage: image)
.resizable()
.aspectRatio(contentMode: .fit)
.edgesIgnoringSafeArea(.top)
.onReceive(imageLoader.didChange) {
data in self.image = UIImage(data: data) ?? UIImage()
}
.onChange(of: url, perform: { value in
imageLoader.loadImage(urlString: value)
})
}
}
}