ios - How to change view on midnight in WidgetKit, SwiftUI?

Question

I have a code:

struct ContentView: View {
    let entry: LessonWidgetEntry
    private static let url: URL = URL(string: "widgetUrl")!
    var body: some View {
        VStack {
            switch entry.state {
            case .none:
                ProgramNotStartedView()
            case .currentLesson(let lesson):
                LessonView(lesson: lesson, imageName: entry.program?.imageName)
            case .lessonCompleted(let lesson):
                LessonCompletedView(lesson: lesson)
            case .programCompleted:
                ProgramCompletedView()
            }
        }.widgetURL(ContentView.url)
    }
}

At midnight LessonCompletedView should change to LessonView, but I am not sure how to do that. Any ideas on how to change views on midnight from the widget?

Answer 1

1. Assuming you have an Entry (in your app you have entry.state... but for this example I used a simplified version):

struct SimpleEntry: TimelineEntry {
    let date: Date
    let lesson: Lesson
}

2. Setup your TimelineProvider to refresh timeline after the next midnight:

struct SimpleProvider: TimelineProvider {
    ...

    func getTimeline(in context: Context, completion: @escaping (Timeline<Entry>) -> Void) {
        let currentDate = Date()
        let midnight = Calendar.current.startOfDay(for: currentDate)
        let nextMidnight = Calendar.current.date(byAdding: .day, value: 1, to: midnight)!

        let entries = [
            SimpleEntry(date: currentDate, lesson: Lesson()) // pass the lesson here
        ]

        let timeline = Timeline(entries: entries, policy: .after(nextMidnight))
        completion(timeline)
    }
}

In the TimelineProvider you may pass any lesson you want (depending on the day or the previous lesson - it's up to you). You may also pass a variable to an Entry indicating whether the lesson is completed.

By setting the .after(nextMidnight) policy you indicate when do you want your Timeline (and therefore you Widget View) to be reloaded.