用于发送通知的云功能不起作用

Question

我正在尝试在添加新游戏时向“PLAYER 2”发送通知。 这是我的代码：

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);


exports.sendNewGameNotification= functions.database.ref('/GAMES/{gameId}/PLAYER 2').onWrite(event => {
const player2uid = event.params.val;

const getDeviceTokensPromise = admin.database().ref(`/USERS/${player2uid}/fcm`).once('value');

return Promise.all([getDeviceTokensPromise]).then(results => {

const tokensSnapshot = results[0];
// Notification details.
const payload = {
  'data': { 
        'title': "Tienes una nueva partida"
  }
};

// Listing all tokens, error here below.
const tokens = Object.keys(tokensSnapshot.val());

// Send notifications to all tokens.
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', 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(tokensSnapshot.ref.child(tokens[index]).remove());
      }
    }
  });
  return Promise.all(tokensToRemove);
});
});
});

当它执行时，在firebase控制台中说

 TypeError: Cannot convert undefined or null to object

如果它是 null 但 fcm 在那里，我做错了什么？

Answer 1

我认为不是这个：

const player2uid = event.params.val;

你想要这个：

const player2uid = event.data.val();

编辑：

对您的代码的此更新包含一些添加的检查和简化。这对我有用。

用于存储令牌（或多个令牌）的数据库结构至关重要。令牌是键，而不是值。这些值不重要，可以是简单的占位符，例如布尔值。

例如：

  "USERS" : {
    "Roberto" : {
      "fcm" : {
        "eBUDkvnsvtA:APA...rKe4T8n" : true
      }
    },
    "Juan" : {
      "fcm" : {
        "fTY4wvnsvtA:APA91bGZMtLY6R...09yTLHdP-OqaxMA" : true
      }
    }
  }

.

exports.sendNewGameNotification= functions.database.ref('/GAMES/{gameId}/PLAYER 2').onWrite(event => {
const player2uid = event.data.val();

return admin.database().ref(`/USERS/${player2uid}`).once('value').then(snapshot => {
   if (!snapshot.exists()) {
        console.log('Player not found:', player2uid);
        return;
    }
    const tokensSnapshot = snapshot.child('fcm');
    if (!tokensSnapshot.exists()) {
        console.log('No tokens for player: ', player2uid);
        return;
    }

    // Notification details.
    const payload = {
      'data': {
            'title': "Tienes una nueva partida"
      }
    };

    // Listing all tokens, error here below.
    const tokens = Object.keys(tokensSnapshot.val());

    // Send notifications to all tokens.
    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', 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(tokensSnapshot.ref.child(tokens[index]).remove());
          }
        }
      });
      return Promise.all(tokensToRemove);
});
});
});