Swift/iOS：Firebase Remote Config获取值的完成块从未执行

Hey there, let’s figure out why your Firebase Remote Config completion blocks aren’t firing. After looking at your code and logs, here are the key issues to check and fix:

1. Fix Firebase Initialization Order #

The most common reason for this problem is initializing your RemoteConfigValues singleton before calling FirebaseApp.configure(). All Firebase services (including Remote Config) need to be properly configured first before any calls to them will work as expected.

• In your AppDelegate (or SceneDelegate for iOS 13+), make sure you call FirebaseApp.configure() first, then access your singleton:

  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
      // First configure Firebase
      FirebaseApp.configure()
      // Then initialize your RemoteConfig singleton
      _ = RemoteConfigValues.sharedInstance
      return true
  }
  

2. Correct Mismatched Completion Block Signatures #

Looking at your fetchCloudValuesWith method, the activate call uses an incorrect closure signature. For Firebase 6.x+, the activate(completion:) method expects a closure that takes two parameters: a Bool indicating if values changed, and an optional Error. Your current code only accepts an Error parameter, which means the closure won’t be invoked properly.

Update that section to match the correct signature:

RemoteConfig.remoteConfig().activate { (changed, error) in
    if let error = error {
        print("Uh-oh. Got an error activating remote values: \(error.localizedDescription)")
    } else {
        print("Remote values activated successfully, values changed: \(changed)")
    }
}

While your fetch closure looks correct, always double-check that closure signatures match the Firebase API documentation—mismatched parameters are a frequent cause of silent callback failures.

3. Use the Recommended fetchAndActivate Method #

Firebase recommends using fetchAndActivate() (which combines fetching and activating values in a single call) instead of separate fetch() and activate() methods, especially in newer SDK versions. Your fetchCloudValues method already uses this, so consider replacing fetchCloudValuesWith with this simpler, more reliable approach.

Update your singleton’s initialization to use this method:

private override init() {
    super.init()
    let settings = RemoteConfigSettings()
    // WARNING: Only set minimumFetchInterval to 0 in debug builds
    #if DEBUG
    settings.minimumFetchInterval = 0
    #endif
    RemoteConfig.remoteConfig().configSettings = settings
    loadDefaultValues()
    fetchCloudValues() // Use the combined fetch + activate method
}

4. Limit Debug-Only Settings to Debug Builds #

Setting minimumFetchInterval = 0 bypasses Firebase’s caching, which is great for testing, but can cause throttling or unexpected behavior in release builds. Wrapping this setting in a #if DEBUG block ensures it only applies when you’re testing locally.

5. Check for Firebase Throttling #

Even with minimumFetchInterval = 0, Firebase might throttle frequent fetch requests if you’re hitting the API too quickly. If you’ve been testing repeatedly, wait a minute or two and try again. You can also check the Firebase Console’s Remote Config section for any throttling warnings.

From your logs, the fetch process completes successfully (you see "Fetch with user properties completed"), so the issue is almost certainly related to initialization order or mismatched callback signatures. Start with verifying the Firebase configure order—it’s the most likely fix.

内容的提问来源于stack exchange，提问作者Dom Bryan