[Connectivity] add a method to request location on iOS (for iOS 13) (flutter#1999)

Author: Chris Yang

packages/connectivity/CHANGELOG.md

@@ -1,3 +1,9 @@
+## 0.4.4
+
+* Add `requestLocationServiceAuthorization` to request location authorization on iOS.
+* Add `getLocationServiceAuthorization` to get location authorization status on iOS.
+* Update README: add more information on iOS 13 updates with CNCopyCurrentNetworkInfo.
+
 ## 0.4.3+7
 
 * Update README with the updated information about CNCopyCurrentNetworkInfo on iOS 13.

packages/connectivity/README.md

@@ -50,7 +50,7 @@ dispose() {
 }
 ```
 
-You can get WIFI related information using:
+You can get wi-fi related information using:
 
 ```dart
 import 'package:connectivity/connectivity.dart';
@@ -60,17 +60,39 @@ var wifiIP = await (Connectivity().getWifiIP());network
 var wifiName = await (Connectivity().getWifiName());wifi network
 ```
 
-### Known Issues
+### iOS 12
 
-#### iOS 13
+To use `.getWifiBSSID()` and `.getWifiName()` on iOS >= 12, the `Access WiFi information capability` in XCode must be enabled. Otherwise, both methods will return null.
 
-The methods `.getWifiBSSID()` and `.getWifiName()` utilize the [CNCopyCurrentNetworkInfo](https://developer.apple.com/documentation/systemconfiguration/1614126-cncopycurrentnetworkinfo) function on iOS.
+### iOS 13
 
-As of iOS 13, Apple announced that these APIs will no longer return valid information by default and will instead return the following:
-> SSID: "Wi-Fi" or "WLAN" ("WLAN" will be returned for the China SKU)  
-> BSSID: "00:00:00:00:00:00"
+The methods `.getWifiBSSID()` and `.getWifiName()` utilize the [`CNCopyCurrentNetworkInfo`](https://developer.apple.com/documentation/systemconfiguration/1614126-cncopycurrentnetworkinfo) function on iOS.
 
-You can follow issue [#37804](https://github.com/flutter/flutter/issues/37804) for the changes required to return valid SSID and BSSID values with iOS 13.
+As of iOS 13, Apple announced that these APIs will no longer return valid information.
+An app linked against iOS 12 or earlier receives pseudo-values such as:
+
+ * SSID: "Wi-Fi" or "WLAN" ("WLAN" will be returned for the China SKU).
+
+ * BSSID: "00:00:00:00:00:00"
+
+An app linked against iOS 13 or later receives `null`.
+
+The `CNCopyCurrentNetworkInfo` will work for Apps that:
+
+  * The app uses Core Location, and has the user’s authorization to use location information.
+
+  * The app uses the NEHotspotConfiguration API to configure the current Wi-Fi network.
+
+  * The app has active VPN configurations installed.
+
+If your app falls into the last two categories, it will work as it is. If your app doesn't fall into the last two categories,
+and you still need to access the wifi information, you should request user's authorization to use location information.
+
+There is a helper method provided in this plugin to request the location authorization: `requestLocationServiceAuthorization`.
+To request location authorization, make sure to add the following keys to your _Info.plist_ file, located in `<project root>/ios/Runner/Info.plist`:
+
+* `NSLocationAlwaysAndWhenInUseUsageDescription` - describe why the app needs access to the user’s location information all the time (foreground and background). This is called _Privacy - Location Always and When In Use Usage Description_ in the visual editor.
+* `NSLocationWhenInUseUsageDescription` - describe why the app needs access to the user’s location information when the app is running in the foreground. This is called _Privacy - Location When In Use Usage Description_ in the visual editor.
 
 ## Getting Started
 

packages/connectivity/example/ios/Runner/Info.plist

@@ -22,6 +22,10 @@
 	<string>1</string>
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
+	<key>NSLocationAlwaysAndWhenInUseUsageDescription</key>
+	<string>This app requires accessing your location information all the time to get wi-fi information.</string>
+	<key>NSLocationWhenInUseUsageDescription</key>
+	<string>This app requires accessing your location information when the app is in foreground to get wi-fi information.</string>
 	<key>UILaunchStoryboardName</key>
 	<string>LaunchScreen</string>
 	<key>UIMainStoryboardFile</key>

packages/connectivity/example/ios/Runner/Runner.entitlements

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>com.apple.developer.networking.wifi-info</key>
+	<true/>
+</dict>
+</plist>

packages/connectivity/example/lib/main.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:async';
+import 'dart:io';
 
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
@@ -90,14 +91,44 @@ class _MyHomePageState extends State<MyHomePage> {
         String wifiName, wifiBSSID, wifiIP;
 
         try {
-          wifiName = await _connectivity.getWifiName();
+          if (Platform.isIOS) {
+            LocationAuthorizationStatus status =
+                await _connectivity.getLocationServiceAuthorization();
+            if (status == LocationAuthorizationStatus.notDetermined) {
+              status =
+                  await _connectivity.requestLocationServiceAuthorization();
+            }
+            if (status == LocationAuthorizationStatus.authorizedAlways ||
+                status == LocationAuthorizationStatus.authorizedWhenInUse) {
+              wifiName = await _connectivity.getWifiName();
+            } else {
+              wifiName = await _connectivity.getWifiName();
+            }
+          } else {
+            wifiName = await _connectivity.getWifiName();
+          }
         } on PlatformException catch (e) {
           print(e.toString());
           wifiName = "Failed to get Wifi Name";
         }
 
         try {
-          wifiBSSID = await _connectivity.getWifiBSSID();
+          if (Platform.isIOS) {
+            LocationAuthorizationStatus status =
+                await _connectivity.getLocationServiceAuthorization();
+            if (status == LocationAuthorizationStatus.notDetermined) {
+              status =
+                  await _connectivity.requestLocationServiceAuthorization();
+            }
+            if (status == LocationAuthorizationStatus.authorizedAlways ||
+                status == LocationAuthorizationStatus.authorizedWhenInUse) {
+              wifiBSSID = await _connectivity.getWifiBSSID();
+            } else {
+              wifiBSSID = await _connectivity.getWifiBSSID();
+            }
+          } else {
+            wifiBSSID = await _connectivity.getWifiBSSID();
+          }
         } on PlatformException catch (e) {
           print(e.toString());
           wifiBSSID = "Failed to get Wifi BSSID";

packages/connectivity/example/test_driver/connectivity.dart

@@ -1,4 +1,5 @@
 import 'dart:async';
+import 'dart:io';
 import 'package:flutter_driver/driver_extension.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:connectivity/connectivity.dart';
@@ -28,5 +29,13 @@ void main() {
           break;
       }
     });
+
+    test('test location methods, iOS only', () async {
+      print(Platform.isIOS);
+      if (Platform.isIOS) {
+        expect((await _connectivity.getLocationServiceAuthorization()),
+            LocationAuthorizationStatus.notDetermined);
+      }
+    });
   });
 }

packages/connectivity/ios/Classes/ConnectivityPlugin.m

@@ -6,13 +6,18 @@
 
 #import "Reachability/Reachability.h"
 
+#import <CoreLocation/CoreLocation.h>
+#import "FLTConnectivityLocationHandler.h"
 #import "SystemConfiguration/CaptiveNetwork.h"
 
 #include <ifaddrs.h>
 
 #include <arpa/inet.h>
 
-@interface FLTConnectivityPlugin () <FlutterStreamHandler>
+@interface FLTConnectivityPlugin () <FlutterStreamHandler, CLLocationManagerDelegate>
+
+@property(strong, nonatomic) FLTConnectivityLocationHandler* locationHandler;
+
 @end
 
 @implementation FLTConnectivityPlugin {
@@ -111,6 +116,18 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
     result([self getBSSID]);
   } else if ([call.method isEqualToString:@"wifiIPAddress"]) {
     result([self getWifiIP]);
+  } else if ([call.method isEqualToString:@"getLocationServiceAuthorization"]) {
+    result([self convertCLAuthorizationStatusToString:[FLTConnectivityLocationHandler
+                                                          locationAuthorizationStatus]]);
+  } else if ([call.method isEqualToString:@"requestLocationServiceAuthorization"]) {
+    NSArray* arguments = call.arguments;
+    BOOL always = [arguments.firstObject boolValue];
+    __weak typeof(self) weakSelf = self;
+    [self.locationHandler
+        requestLocationAuthorization:always
+                          completion:^(CLAuthorizationStatus status) {
+                            result([weakSelf convertCLAuthorizationStatusToString:status]);
+                          }];
   } else {
     result(FlutterMethodNotImplemented);
   }
@@ -121,6 +138,34 @@ - (void)onReachabilityDidChange:(NSNotification*)notification {
   _eventSink([self statusFromReachability:curReach]);
 }
 
+- (NSString*)convertCLAuthorizationStatusToString:(CLAuthorizationStatus)status {
+  switch (status) {
+    case kCLAuthorizationStatusNotDetermined: {
+      return @"notDetermined";
+    }
+    case kCLAuthorizationStatusRestricted: {
+      return @"restricted";
+    }
+    case kCLAuthorizationStatusDenied: {
+      return @"denied";
+    }
+    case kCLAuthorizationStatusAuthorizedAlways: {
+      return @"authorizedAlways";
+    }
+    case kCLAuthorizationStatusAuthorizedWhenInUse: {
+      return @"authorizedWhenInUse";
+    }
+    default: { return @"unknown"; }
+  }
+}
+
+- (FLTConnectivityLocationHandler*)locationHandler {
+  if (!_locationHandler) {
+    _locationHandler = [FLTConnectivityLocationHandler new];
+  }
+  return _locationHandler;
+}
+
 #pragma mark FlutterStreamHandler impl
 
 - (FlutterError*)onListenWithArguments:(id)arguments eventSink:(FlutterEventSink)eventSink {

packages/connectivity/ios/Classes/FLTConnectivityLocationHandler.h

@@ -0,0 +1,22 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#import <CoreLocation/CoreLocation.h>
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@class FLTConnectivityLocationDelegate;
+
+typedef void (^FLTConnectivityLocationCompletion)(CLAuthorizationStatus);
+
+@interface FLTConnectivityLocationHandler : NSObject
+
++ (CLAuthorizationStatus)locationAuthorizationStatus;
+
+- (void)requestLocationAuthorization:(BOOL)always
+                          completion:(_Nonnull FLTConnectivityLocationCompletion)completionHnadler;
+
+@end
+
+NS_ASSUME_NONNULL_END

packages/connectivity/ios/Classes/FLTConnectivityLocationHandler.m

@@ -0,0 +1,58 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "FLTConnectivityLocationHandler.h"
+
+@interface FLTConnectivityLocationHandler () <CLLocationManagerDelegate>
+
+@property(copy, nonatomic) FLTConnectivityLocationCompletion completion;
+@property(strong, nonatomic) CLLocationManager *locationManager;
+
+@end
+
+@implementation FLTConnectivityLocationHandler
+
++ (CLAuthorizationStatus)locationAuthorizationStatus {
+  return CLLocationManager.authorizationStatus;
+}
+
+- (void)requestLocationAuthorization:(BOOL)always
+                          completion:(FLTConnectivityLocationCompletion)completionHandler {
+  CLAuthorizationStatus status = CLLocationManager.authorizationStatus;
+  if (status != kCLAuthorizationStatusAuthorizedWhenInUse && always) {
+    completionHandler(kCLAuthorizationStatusDenied);
+    return;
+  } else if (status != kCLAuthorizationStatusNotDetermined) {
+    completionHandler(status);
+    return;
+  }
+
+  if (self.completion) {
+    // If a request is still in process, immediately return.
+    completionHandler(kCLAuthorizationStatusNotDetermined);
+    return;
+  }
+
+  self.completion = completionHandler;
+  self.locationManager = [CLLocationManager new];
+  self.locationManager.delegate = self;
+  if (always) {
+    [self.locationManager requestAlwaysAuthorization];
+  } else {
+    [self.locationManager requestWhenInUseAuthorization];
+  }
+}
+
+- (void)locationManager:(CLLocationManager *)manager
+    didChangeAuthorizationStatus:(CLAuthorizationStatus)status {
+  if (status == kCLAuthorizationStatusNotDetermined) {
+    return;
+  }
+  if (self.completion) {
+    self.completion(status);
+    self.completion = nil;
+  }
+}
+
+@end