Reloading individual rows properties in SwiftUI List

Question

I am trying to give the user the opportunity to save or unsave a news article. The Save button saves it on the backend but the image does not update when the backend updates.

@State var industryInsights = [IndustryInsight]()

    List {
        ForEach(industryInsights, id: \.self) { insight in
            IndustryInsightRowView(insight: insight)
        }
    }

I am not sure the best way of doing this, but I would like the button image to update as the user presses the button. Any help would be appreciated.

InsightClass and properties

struct IndustryInsight: Codable, Hashable, Identifiable {
    let id: Int
    let industry, alert, date: String
    let url: String
    let status: String
}

Function when save button pressed.

func saverowButtonClicked(alert: IndustryInsight) {
    if alert.status == "Saved" {
        RestAPI.changeStatusIndustryAlerts(id: alert.id, status: "Unsave", completionHandler: { () in
        })
    } else {
        RestAPI.changeStatusIndustryAlerts(id: alert.id, status: "Save", completionHandler: { () in
        })
    }
}

In SwiftUI you can't really reload an individual row, just let the system handle it. In the `changeStatusIndustryAlerts` closure, modify your `industryInsights` array and the List will automatically update. — aheze, Jul 06 '21 at 16:42
@aheze thank you, could you show me what you mean.. the industryInsights Array is in another class though — Luke Tomlinson, Jul 06 '21 at 16:44
You'll need to update your `industryInsights` `@State` variable. — jnpdx, Jul 06 '21 at 16:45
@LukeTomlinson what class is your `saverowButtonClicked` func in? It's got to be related to your ContentView somehow — aheze, Jul 06 '21 at 16:46
@aheze I have a RowView() with all those functions in it when a button is pressed. Then In my contentView() I have a List of RowView() — Luke Tomlinson, Jul 06 '21 at 16:49
Might want to consider using a `Binding` for `IndustryInsightRowView`'s `insight` property, so any changes there will be passed back up to `ContentView`. Note that you'll need to [loop over `industryInsights`'s indices](https://stackoverflow.com/a/57837054/14351818) instead, unless you're developing for iOS 15? — aheze, Jul 06 '21 at 16:56
@aheze I need the property of Status to be reloaded when changeStatus is called — Luke Tomlinson, Jul 06 '21 at 17:56
How did you implement the Hashable protocol for IndustryInsight struct? If done in the right way it should fire the reload of a row when changed — DungeonDev, Mar 12 '22 at 23:24

score 1 · Accepted Answer · answered Jul 06 '21 at 20:41

1

I am trying to avoid using @State as much as possible and using @ObservableObject and @Published instead. Try converting your IndustryInsight struct to an ObservableObject class and let IndustryInsightRowView accept it as an @ObservedObject.

answered Jul 06 '21 at 20:41

Guy Nir

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Reloading individual rows properties in SwiftUI List

1 Answers1