Adapt store of the openFeedsInDefaultBrowser preference to be stored/retrieved from app group shared defaults, so that the Safari App Extension can access it.

Mac/AppDefaults.swift

@@ -107,12 +107,24 @@ final class AppDefaults {
 		}
 	}
 
+	// Special case for this default: store/retrieve it from the shared app group
+	// defaults, so that it can be resolved by the Safari App Extension.
+	var subscribeToFeedDefaults: UserDefaults {
+		if let appGroupID = Bundle.main.object(forInfoDictionaryKey: "AppGroup") as? String,
+		   let appGroupDefaults = UserDefaults(suiteName: appGroupID) {
+			return appGroupDefaults
+		}
+		else {
+			return UserDefaults.standard
+		}
+	}
+
 	var subscribeToFeedsInDefaultBrowser: Bool {
 		get {
-			return AppDefaults.bool(for: Key.subscribeToFeedsInDefaultBrowser)
+			return subscribeToFeedDefaults.bool(forKey: Key.subscribeToFeedsInDefaultBrowser)
 		}
 		set {
-			AppDefaults.setBool(for: Key.subscribeToFeedsInDefaultBrowser, newValue)
+			subscribeToFeedDefaults.set(newValue, forKey: Key.subscribeToFeedsInDefaultBrowser)
 		}
 	}
 
@@ -297,7 +309,6 @@ final class AppDefaults {
 										Key.detailFontSize: FontSize.medium.rawValue,
 										Key.timelineSortDirection: ComparisonResult.orderedDescending.rawValue,
 										Key.timelineGroupByFeed: false,
-										Key.subscribeToFeedsInDefaultBrowser: false,
 										"NSScrollViewShouldScrollUnderTitlebar": false,
 										Key.refreshInterval: RefreshInterval.everyHour.rawValue,
 										Key.showDebugMenu: showDebugMenu]

Mac/Base.lproj/Preferences.storyboard

@@ -190,7 +190,7 @@
                                             <font key="font" metaFont="system"/>
                                         </buttonCell>
                                         <connections>
-                                            <binding destination="mAF-gO-1PI" name="value" keyPath="values.subscribeToFeedsInDefaultBrowser" id="rgT-1E-AoD">
+                                            <binding destination="iuH-lz-18x" name="value" keyPath="openFeedsInDefaultNewsReader" id="l1B-rk-qfE">
                                                 <dictionary key="options">
                                                     <string key="NSValueTransformerName">NSNegateBoolean</string>
                                                 </dictionary>
@@ -204,7 +204,7 @@
                                             <font key="font" metaFont="system"/>
                                         </buttonCell>
                                         <connections>
-                                            <binding destination="mAF-gO-1PI" name="value" keyPath="values.subscribeToFeedsInDefaultBrowser" id="Dnc-co-ppt"/>
+                                            <binding destination="iuH-lz-18x" name="value" keyPath="openFeedsInDefaultNewsReader" id="QZ4-W8-rPi"/>
                                         </connections>
                                     </button>
                                 </subviews>

Mac/Preferences/General/GeneralPrefencesViewController.swift

@@ -126,4 +126,12 @@ private extension GeneralPreferencesViewController {
 		}
 	}
 
+	@objc var openFeedsInDefaultNewsReader: Bool {
+		get {
+			return AppDefaults.shared.subscribeToFeedsInDefaultBrowser
+		}
+		set {
+			AppDefaults.shared.subscribeToFeedsInDefaultBrowser = newValue
+		}
+	}
 }

Mac/SafariExtension/Info.plist

@@ -8,6 +8,8 @@
 	<string>Subscribe to Feed</string>
 	<key>CFBundleExecutable</key>
 	<string>$(EXECUTABLE_NAME)</string>
+	<key>AppGroup</key>
+	<string>group.$(ORGANIZATION_IDENTIFIER).NetNewsWire-Evergreen</string>
 	<key>CFBundleIdentifier</key>
 	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
 	<key>CFBundleInfoDictionaryVersion</key>

Mac/SafariExtension/SafariExtensionHandler.swift

@@ -45,15 +45,11 @@ class SafariExtensionHandler: SFSafariExtensionHandler {
 			if var feedURLString = userInfo?["url"] as? String {
 				var openInDefaultBrowser = false
 
-				// Ask for the user default from NetNewsWire's defaults to determine whether to open the feed URL
-				// using whatever the system configured default is, or to always hard-code it to NetNewsWire itself.
-				if let pluginBundleID = Bundle.main.bundleIdentifier {
-					// By convention we assume that our bundle ID will always be the same as the host app's, with
-					// the addition of ".Subscribe-to-Feed".
-					let hostAppBundleID = pluginBundleID.replacingOccurrences(of: ".Subscribe-to-Feed", with: "")
-
-					if let sharedDefaults = UserDefaults(suiteName: hostAppBundleID) {
-						openInDefaultBrowser = sharedDefaults.bool(forKey: "subscribeToFeedsInDefaultBrowser")
+				// Ask for the user's choice for whether to open the feed URL using whatever the system
+				// configured default is, or to always hard-code it to have NetNewsWire handle it itself.
+				if let appGroupID = Bundle.main.object(forInfoDictionaryKey: "AppGroup") as? String {
+					if let groupDefaults = UserDefaults(suiteName: appGroupID) {
+						openInDefaultBrowser = groupDefaults.bool(forKey: "subscribeToFeedsInDefaultBrowser")
 					}
 				}