From d204b03633bdbe8dfea5645893b52a4d828545e5 Mon Sep 17 00:00:00 2001
From: Tony Li <tony.li@automattic.com>
Date: Fri, 30 Jun 2023 19:47:24 +1200
Subject: [PATCH] Retain a notification observer in StatsForegroundObservable

---
 .../Stats/StatsForegroundObservable.swift     | 20 +++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/WordPress/Classes/ViewRelated/Stats/StatsForegroundObservable.swift b/WordPress/Classes/ViewRelated/Stats/StatsForegroundObservable.swift
index 447af1b75cf2..63d45d12e1ef 100644
--- a/WordPress/Classes/ViewRelated/Stats/StatsForegroundObservable.swift
+++ b/WordPress/Classes/ViewRelated/Stats/StatsForegroundObservable.swift
@@ -4,9 +4,11 @@ protocol StatsForegroundObservable: AnyObject {
     func reloadStatsData()
 }
 
+private var observerKey = 0
+
 extension StatsForegroundObservable where Self: UIViewController {
     func addWillEnterForegroundObserver() {
-        NotificationCenter.default.addObserver(forName: UIApplication.willEnterForegroundNotification,
+        enterForegroundObserver = NotificationCenter.default.addObserver(forName: UIApplication.willEnterForegroundNotification,
                                                object: nil,
                                                queue: nil) { [weak self] _ in
             self?.reloadStatsData()
@@ -14,8 +16,18 @@ extension StatsForegroundObservable where Self: UIViewController {
     }
 
     func removeWillEnterForegroundObserver() {
-        NotificationCenter.default.removeObserver(self,
-                                                  name: UIApplication.willEnterForegroundNotification,
-                                                  object: nil)
+        if let enterForegroundObserver {
+            NotificationCenter.default.removeObserver(enterForegroundObserver)
+        }
+        enterForegroundObserver = nil
+    }
+
+    private var enterForegroundObserver: NSObjectProtocol? {
+        get {
+            objc_getAssociatedObject(self, &observerKey) as? NSObjectProtocol
+        }
+        set {
+            objc_setAssociatedObject(self, &observerKey, newValue, .OBJC_ASSOCIATION_RETAIN)
+        }
     }
 }