Stop Polling APIs in Widgets: Build a Snapshot Broker Instead

Stop Polling APIs in Widgets: Build a Snapshot Broker Instead

A widget should be a fast reader, not a network-heavy client. If every timeline request hits your API, refresh budgets disappear and stale UI follows. A snapshot broker pattern fixes this.

Step 1: centralize data fetch in the host app

struct WidgetSnapshot: Codable {
    let generatedAt: Date
    let headline: String
    let progress: Double
}

Step 2: persist snapshots to shared app group storage

let url = FileManager.default
  .containerURL(forSecurityApplicationGroupIdentifier: "group.learnitfree")!
  .appendingPathComponent("widget-snapshot.json")

Step 3: let widget timeline read local snapshot first

let entry = try SnapshotStore.load() ?? .placeholder
return Timeline(entries: [entry], policy: .after(Date().addingTimeInterval(1800)))

Pitfall

Making widget extension own API auth and retries. This creates fragile, battery-hungry behavior.

Verification

• Widget renders instantly from local snapshot.
• Host app refresh updates next widget timeline cycle.
• API outages do not blank out widget content.