Working with Change Streams from Your Swift Application

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@State private var changeStream: ChangeStream<ChangeStreamEvent<BSONDocument>>?

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@State private var latestChangeEvent: ChangeStreamEvent<BSONDocument>?

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func registerChangeStream() async {
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    // If the view already has an active change stream, close it down
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    if let changeStream = changeStream {
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        _ = changeStream.kill()
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        self.changeStream = nil
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    }
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    if enabledChangeStreams {
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        do {
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            let changeStreamOptions = ChangeStreamOptions(fullDocument: .updateLookup)
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            changeStream = try await collection?.watch(options: changeStreamOptions)
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            _ = changeStream?.forEach({ changeEvent in
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                withAnimation {
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                    latestChangeEvent = changeEvent
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                    showingChangeEvent = true
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                    Task {
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                        await loadDocs()
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                    }
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                }
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            })
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        } catch {
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            errorMessage = "Failed to register change stream: \(error.localizedDescription)"
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        }
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    }
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}

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 ChangeEventView(event: latestChangeEvent)

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let event: ChangeStreamEvent<BSONDocument>

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var color: Color {
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    switch event.operationType {  
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    case .insert:
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        return .green
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    case .update:
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        return .yellow
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    case .replace:
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        return .orange
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    case .delete:
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        return .red
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    default:
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        return .teal
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    }
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}

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if let documentKey = event.documentKey {
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   ...
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        Text(documentKey.toPrettyJSONString())
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   ...
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    }
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}

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if let updateDescription = event.updateDescription {
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    ...
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        Text(updateDescription.updatedFields.toPrettyJSONString())
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    ...
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    }
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}

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if let fullDocument = event.fullDocument {
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    ...
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        Text(fullDocument.toPrettyJSONString())
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    ...
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    }
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}