安卓Firebase云函数通知

Question

安卓Firebase云函数通知

androidfirebasepush-notificationgoogle-cloud-functions

3

我已经成功设置了Firebase云函数以向主题发送通知。问题在于它会发送给包括发送者在内的所有用户，如何设置我的云函数，使它不向发送者显示通知？请帮忙解决？以下是我向主题发送通知的方式：

exports.sendNotesNotification = functions.database.ref('/Notes/{pushId}')
    .onWrite(event => {
        const notes = event.data.val();

        const payload = {
                notification: {

                    username: notes.username,
                    title: notes.title,
                    body: notes.desc

                }

            }

            admin.messaging().sendToTopic("New_entry", payload)
            .then(function(response){
                console.log("Successfully sent notes: ", response);
            })
            .catch(function(error){
                console.log("Error sending notes: ", error);
            });
        });

- Dexter Fury Kombat Zone

你必须知道发送者的 FCM ID。由于你要发送给所有人，只需检查并排除发送者的 FCM ID，然后发送通知。 - Ajinkya S

请展示一些Node.js的代码示例，我是新手。 - Dexter Fury Kombat Zone

1个回答

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- Ramiz Ansari · Accepted Answer

根据Firebase文档中的说明，使用主题发布通知应该针对公共且不是时间关键的通知。在您的情况下，通知不是公共的，并且发送方也订阅了特定主题，因此他也会收到通知。因此，如果您想避免将通知发送给发送方，则必须取消其订阅您的主题。

或者更好的解决方案是，使用它们的FCM令牌向单个设备发送通知。用于发送FCM令牌通知的Node.js代码如下：

admin.messaging().sendToDevice(<array of tokens>, payload);

你可以从你的安卓 FirebaseInstanceIdService 的 onTokenRefresh() 方法中获取设备令牌。

 @Override
    public void onTokenRefresh() {
        // Get updated InstanceID token.
        String refreshedToken = FirebaseInstanceId.getInstance().getToken();
        // TO DO: send token to your server or firebase database
}

更新：

现在将Firebase令牌存储到您的数据库中，您应该按照以下方式构建您的数据库结构：

   -users
      |-user1uid
      |   |-name //your choice
      |   |-email //your choice
      |   |-fcmTokens
      |        |-valueOftoken1:true
      |        |-valueOftoken2:true
   -notes
      |  |-notesId
      |      |-yourdata
      |      |-createdBy:uidofUser  //user who created note
      |
   -subscriptions       //when onWrite() will trigger we will use this to get UID of all subscribers of creator of "note". 
      |      |-uidofUser    
      |           |-uidofSubscriber1:true //user subscribe to notes written. by parent node uid
      |           |-uidofSubscriber2:true

要将令牌保存在数据库中，这里是onTokenRefresh()的代码：

 @Override
        public void onTokenRefresh() {
            // Get updated InstanceID token.
            String refreshedToken = FirebaseInstanceId.getInstance().getToken(); //get refreshed token
            FirebaseAuth mAuth = FirebaseAuth.getInstance();
            FirebaseUser user = mAuth.getCurrentUser(); //get currentto get uid
            if(user!=null){
            DatabaseReference mDatabase = FirebaseDatabase.getInstance().getReference().child("users").child(user.getUid()); // create a reference to userUid in database
            if(refreshedToken!=null) //
              mDatabase.child("fcmTokens").child(refreshedToken).setValue(true); //creates a new node of user's token and set its value to true.
            else
              Log.i(TAG, "onTokenRefresh: token was null");
    }
    Log.d(tag, "Refreshed token SEND TO FIREBASE: " + refreshedToken);
    }

当为该用户创建新令牌时，上述代码将在用户的fcmTokens中创建新节点。

以下是检索用户令牌并向这些令牌发送通知的node.js部分。

exports.sendNotesNotification = functions.database.ref('/Notes/{pushId}')
    .onWrite(event => {

        const notes = event.data.val();
        const createdby = notes.createdBy;
        const getAllSubscribersPromise = admin.database().ref(`/subscriptions/${createdby}/`).once('value'); // retrieving subscribers 

         const payload = {
                notification: {

                    username: notes.username,
                    title: notes.title,
                    body: notes.desc

                }

            }

        return getAllSubscribersPromise.then(result => {
        const userUidSnapShot = result; //results will have children having keys of subscribers uid.
        if (!userUidSnapShot.hasChildren()) {
          return console.log('There are no subscribed users to write notifications.'); 
        }
        console.log('There are', userUidSnapShot.numChildren(), 'users to send notifications to.');
        const users = Object.keys(userUidSnapShot.val()); //fetched the keys creating array of subscribed users

        var AllFollowersFCMPromises = []; //create new array of promises of TokenList for every subscribed users
        for (var i = 0;i<userUidSnapShot.numChildren(); i++) {
            const user=users[i];
            console.log('getting promise of user uid=',user);
            AllFollowersFCMPromises[i]= admin.database().ref(`/users/${user}/fcmToken/`).once('value');
        }

        return Promise.all(AllFollowersFCMPromises).then(results => {

            var tokens = []; // here is created array of tokens now ill add all the fcm tokens of all the user and then send notification to all these.
            for(var i in results){
                var usersTokenSnapShot=results[i];
                console.log('For user = ',i);
                if(usersTokenSnapShot.exists()){
                    if (usersTokenSnapShot.hasChildren()) { 
                        const t=  Object.keys(usersTokenSnapShot.val()); //array of all tokens of user [n]
                        tokens = tokens.concat(t); //adding all tokens of user to token array
                        console.log('token[s] of user = ',t);
                    }
                    else{

                    }
                }
            }
            console.log('final tokens = ',tokens," notification= ",payload);
            return admin.messaging().sendToDevice(tokens, payload).then(response => {
      // For each message check if there was an error.
                const tokensToRemove = [];
                response.results.forEach((result, index) => {
                    const error = result.error;
                    if (error) {
                        console.error('Failure sending notification to uid=', tokens[index], error);
                        // Cleanup the tokens who are not registered anymore.
                        if (error.code === 'messaging/invalid-registration-token' || error.code === 'messaging/registration-token-not-registered') {
                            tokensToRemove.push(usersTokenSnapShot.ref.child(tokens[index]).remove());
                        }
                    }
                    else{
                        console.log("notification sent",result);
                    }
                });

                return Promise.all(tokensToRemove);
            });

            return console.log('final tokens = ',tokens," notification= ",payload);
        });





            });
        });

我还没有检查过Node.js部分，请告诉我您是否仍然有问题。