如何使用 Cloud Functions for Firebase 向特定用户发送推送通知

Question

我正在使用Firebase作为我的Android应用程序的后端，并且对使用Firebase的Cloud Functions非常陌生，我想知道如何在事件发生时向特定用户发送推送通知。

例如，当在数据库的 adminName 节点发生写入时，我将如何向在以下代码中使用 uId 的用户发送推送通知：

exports.sendNotification = functions.database.ref('/users/{uId}/groups/{adminName}')
    .onWrite(event => {
    // Grab the current value of what was written to the Realtime Database.
    var eventSnapshot = event.data;
    var str1 = "Author is ";
    var str = str1.concat(eventSnapshot.child("author").val());
    console.log(str);
    var topic = "android";
    var payload = {
        data: {
            title: eventSnapshot.child("title").val(),
            author: eventSnapshot.child("author").val()
        }
    };
    // Send a message to devices subscribed to the provided topic.
    return admin.messaging().sendToTopic(topic, payload)
        .then(function (response) {
            // See the MessagingTopicResponse reference documentation for the
            // contents of response.
            console.log("Successfully sent message:", response);
        })
        .catch(function (error) {
            console.log("Error sending message:", error);
        });
    });

Answer 1

进行以下更改。 它对我有用

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().functions);
var newData;
exports.myTrigger = functions.firestore.document('TestCollection/{id}').onWrite(async (snapshot, context) => {
//
if (snapshot.empty) {
    console.log('No Devices');
    return;
}
newData = snapshot.data();
const deviceIdTokens = await admin
    .firestore()
    .collection('DeviceIDTokens')
    .get();
var tokens = [];
for (var token of deviceIdTokens.docs) {
    tokens.push(token.data().device_token);
}
var payload = {
    notification: {
        title: 'Push Title',
        body: 'Push Body',
        sound: 'default',
    },
    data: {
        push_key: 'Push Key Value',
        key1: newData.data,
    },
};
try {
    const response = await admin.messaging().sendToDevice(tokens, payload);
    console.log('Notification sent successfully');
} catch (err) {
    console.log(err);
}
});