Add method to listen for changes to the access token (#666)

facebookarchive · Nov 7, 2019 · 26278c9 · 26278c9
1 parent 5d016be
commit 26278c9
Show file tree

Hide file tree

Showing 4 changed files with 76 additions and 3 deletions.
diff --git a/android/src/main/java/com/facebook/reactnative/androidsdk/FBAccessTokenModule.java b/android/src/main/java/com/facebook/reactnative/androidsdk/FBAccessTokenModule.java
@@ -22,6 +22,7 @@
 package com.facebook.reactnative.androidsdk;
 
 import com.facebook.AccessToken;
+import com.facebook.AccessTokenTracker;
 import com.facebook.FacebookException;
 import com.facebook.react.bridge.Callback;
 import com.facebook.react.bridge.NativeModule;
@@ -31,6 +32,7 @@
 import com.facebook.react.bridge.ReactMethod;
 import com.facebook.react.bridge.ReadableMap;
 import com.facebook.react.module.annotations.ReactModule;
+import com.facebook.react.modules.core.DeviceEventManagerModule;
 
 /**
  * This is a {@link NativeModule} that allows JS to use AcessToken in Facebook Android SDK.
@@ -39,9 +41,21 @@
 public class FBAccessTokenModule extends ReactContextBaseJavaModule {
 
     public static final String NAME = "FBAccessToken";
+    public static final String CHANGE_EVENT_NAME = "fbsdk.accessTokenDidChange";
+
+    private final ReactApplicationContext mReactContext;
+    private final AccessTokenTracker accessTokenTracker = new AccessTokenTracker() {
+        @Override
+        protected void onCurrentAccessTokenChanged(AccessToken oldAccessToken, AccessToken currentAccessToken) {
+            mReactContext
+                    .getJSModule(DeviceEventManagerModule.RCTDeviceEventEmitter.class)
+                    .emit(CHANGE_EVENT_NAME, currentAccessToken == null ? null : Utility.accessTokenToReactMap(currentAccessToken));
+        }
+    };
 
     public FBAccessTokenModule(ReactApplicationContext reactContext) {
         super(reactContext);
+        mReactContext = reactContext;
     }
 
     public String getName() {

diff --git a/ios/RCTFBSDK/core/RCTFBSDKAccessToken.h b/ios/RCTFBSDK/core/RCTFBSDKAccessToken.h
@@ -16,9 +16,9 @@
 // IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 // CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-#import <React/RCTBridgeModule.h>
+#import <React/RCTEventEmitter.h>
 
 #import <FBSDKCoreKit/FBSDKCoreKit.h>
 
-@interface RCTFBSDKAccessToken : NSObject <RCTBridgeModule>
+@interface RCTFBSDKAccessToken : RCTEventEmitter
 @end
diff --git a/ios/RCTFBSDK/core/RCTFBSDKAccessToken.m b/ios/RCTFBSDK/core/RCTFBSDKAccessToken.m
@@ -22,7 +22,11 @@
 
 #import "RCTConvert+FBSDKAccessToken.h"
 
-@implementation RCTFBSDKAccessToken
+static NSString *const kFBSDKAccessTokenDidChangeEvent = @"fbsdk.accessTokenDidChange";
+
+@implementation RCTFBSDKAccessToken {
+  BOOL _isObserving;
+}
 
 RCT_EXPORT_MODULE(FBAccessToken);
 
@@ -56,6 +60,38 @@ - (dispatch_queue_t)methodQueue
   }];
 }
 
+#pragma mark - Event Methods
+
+- (NSArray *)supportedEvents
+{
+  return @[kFBSDKAccessTokenDidChangeEvent];
+}
+
+- (void)startObserving
+{
+  _isObserving = YES;
+  [[NSNotificationCenter defaultCenter] addObserver:self
+                                           selector:@selector(accessTokenDidChange:)
+                                               name:FBSDKAccessTokenDidChangeNotification
+                                             object:nil];
+}
+
+- (void)stopObserving
+{
+  _isObserving = NO;
+  [[NSNotificationCenter defaultCenter] removeObserver:self
+                                                  name:FBSDKAccessTokenDidChangeNotification
+                                                object:nil];
+}
+
+- (void)accessTokenDidChange:(NSNotification*)notification
+{
+  if ([notification.name isEqualToString:FBSDKAccessTokenDidChangeNotification] && _isObserving) {
+    NSDictionary *body = RCTBuildAccessTokenDict([FBSDKAccessToken currentAccessToken]);
+    [self sendEventWithName:kFBSDKAccessTokenDidChangeEvent body:body ?: [NSNull null]];
+  }
+}
+
 #pragma mark - Helper Functions
 
 static NSDictionary *RCTBuildAccessTokenDict(FBSDKAccessToken *token)

diff --git a/js/FBAccessToken.js b/js/FBAccessToken.js
@@ -25,6 +25,9 @@
 
 const AccessToken = require('react-native').NativeModules.FBAccessToken;
 
+const NativeEventEmitter = require('react-native').NativeEventEmitter;
+const eventEmitter = new NativeEventEmitter(AccessToken);
+
 type AccessTokenMap = {
   accessToken: string,
   permissions: Array<string>,
@@ -140,6 +143,26 @@ class FBAccessToken {
     return AccessToken.refreshCurrentAccessTokenAsync();
   }
 
+  /**
+   * Adds a listener for when the access token changes. Returns a functions which removes the
+   * listener when called.
+   */
+  static addListener(
+    listener: (accessToken: ?FBAccessToken) => void,
+  ): () => void {
+    const subscription = eventEmitter.addListener(
+      'fbsdk.accessTokenDidChange',
+      (tokenMap: AccessTokenMap) => {
+        if (tokenMap) {
+          listener(new FBAccessToken(tokenMap));
+        } else {
+          listener(null);
+        }
+      },
+    );
+    return () => subscription.remove();
+  }
+
   /**
    * Gets the date at which the access token expires. The value is the number of
    * milliseconds since Jan. 1, 1970, midnight GMT.