带有Firebase云功能的无服务器通知

Question

我使用了firebase聊天通知云功能，但当通知触发我在firebase函数中收到此错误控制台

无法读取未定义的属性"current">

在exports.sendNotification.functions.database.ref.onWrite.event(/user_code/index.js:8:35(

这是我的函数：

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
exports.sendNotification = functions.database.ref('/notifications/messages/{pushId}').onWrite(event => {
console.log('Push notification event triggered for testing');
console.log(event);
const message = event.data.current.val();
const senderUid = message.from;
const receiverUid = message.to;
console.log(receiverUid);
const promises = [];
if (senderUid === receiverUid) {
//if sender is receiver, don't send notification
promises.push(event.data.current.ref.remove());
return Promise.all(promises);
}
const getInstanceIdPromise = admin.database().ref(`/usersnew/${receiverUid}`).once('value');
const getSenderUidPromise = admin.auth().getUser(senderUid);
return Promise.all([getInstanceIdPromise, getSenderUidPromise]).then(results => {
const instanceId = results[0].val();
const sender = results[1];
console.log('notifying ' + receiverUid + ' about ' + message.body + ' from ' + senderUid);
const payload = {
notification: {
title: sender.displayName,
body: message.body,
icon: sender.photoURL
}
};
admin.messaging().sendToDevice(instanceId, payload)
.then(function (response) {
return console.log("Successfully sent message:", response);
})
.catch(function (error) {
console.log("Error sending message:", error);
});
return console.log('This is the notify feature');
});
});

有人知道怎么解决这个问题吗？当我记录事件时，它在控制台中显示如下

{ before: 
DataSnapshot {
app: 
FirebaseApp {
firebaseInternals_: [Object],
services_: {},
isDeleted_: false,
name_: '__admin__',
options_: [Object],
INTERNAL: [Object] },
instance: 'https://teleport-24f52.firebaseio.com',
_path: '/notifications/messages/-LIlFNd2spo_V1rM-G-f',
_data: null },
after: 
DataSnapshot {
app: 
FirebaseApp {
firebaseInternals_: [Object],
services_: {},
isDeleted_: false,
name_: '__admin__',
options_: [Object],
INTERNAL: [Object] },
instance: 'https://teleport-24f52.firebaseio.com',
_path: '/notifications/messages/-LIlFNd2spo_V1rM-G-f',
_data: 
{ body: 'abc',
dayTimestamp: 1532975400000,
from: 'q8gtwtwXqbV2DtpsrbYajFsWzSr2',
negatedTimestamp: -1533056068309,
timestamp: 1533056068309,
to: 'Cmpu7mbIENTYyoHZjCjZnbnBMbl2' } } }
10:22:44.625 PM

Answer 1

在您的代码中，event.data.current应该是event.after.val()、event.after.ref等…

云函数1.0中的API发生了变化。

阅读：https://firebase.google.com/docs/functions/database-events#reading_the_previous_valuehttps://firebase.google.com/docs/functions/beta-v1-diff

Answer 2

也许问题出在SDK版本中。从v1.0开始，情况发生了一些变化。尝试更新SDK并按照以下说明进行漫游：https://firebase.google.com/docs/functions/beta-v1-diff