How to get AsyncImage to update the View with changing image

Question

I'm using an observable object to cause the update of a view - an image file is being updated every second by a driver. But the actual image is not updated, only the opacity property - I was just using opacity to see the change. I was expecting the whole view including the image itself to be updated with a change in the observed object.

Here is the code:

import SwiftUI

struct StreamingImageView: View {
    var filePath = URL(string: "file:/Users/\(NSUserName())/Library/Containers/GB.IndigoPolarAlignAid/Data/img_01.jpg")
    @ObservedObject var monitor: FileMonitor
    
    init(){
        print("StreamingImageView: \(filePath!)")
        monitor = FileMonitor(filePath: filePath!)
    }
    
    var body: some View {
        GeometryReader { geometry in
            AsyncImage(url: filePath)
                .opacity(Double(monitor.fileUpdateCount)/10.0)
            Text("count \(monitor.fileUpdateCount) \(filePath!)")
        }
    }
}

Answer 1

The answer was provided by @jnpdx - in the discussion above - who suggested adding a unique id property - I used the monitor.fileUpdateCount to do this and get an updated display with refreshed jpg as I wanted. Here is minimal code that works:

import SwiftUI

let filePath = URL(string: "file:/Users/\(NSUserName())/Library/Containers/GB.IndigoPolarAlignAid/Data/img_01.jpg")

struct StreamingImageView: View {
    @ObservedObject var monitor: FileMonitor = FileMonitor(filePath: filePath!)
    var id: Int = 0

    var body: some View {
            AsyncImage(url: monitor.filePath)
                    .id(monitor.fileUpdateCount)
}