使用 Firebase 云消息发送通知答案

【问题标题】：sending notification with firebase cloud messaging使用 Firebase 云消息发送通知
【发布时间】：2018-11-22 17:03:45
【问题描述】：

我正在尝试使用我部署到我的 firebase 函数的以下函数在我的应用中向他们发送好友请求时通过 firebase 云消息向用户发送通知

'use strict'

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

exports.sendNotification = functions.database.ref('/Notifications/{user_id}/{notifications_id}').onWrite(event => {
	const user_id = event.params.user_id;
	const notifications = event.params.notifications;

	console.log('This User Id is :', user_id);
});

但是当它尝试发送通知时，我的函数日志中出现以下错误

 sendNotification
	

TypeError: Cannot read property 'user_id' of undefined
    at exports.sendNotification.functions.database.ref.onWrite.event (/user_code/index.js:8:30)
    at cloudFunctionNewSignature (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:105:23)
    at cloudFunction (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:135:20)
    at /var/tmp/worker/worker.js:758:24
    at process._tickDomainCallback (internal/process/next_tick.js:135:7)

【问题讨论】：

通过添加行console.log(event.params)检查user_id是否存在于event.params中

标签： javascript firebase firebase-cloud-messaging

【解决方案1】：

您必须添加上下文并从那里获取参数。试试：

            ..'use strict'

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

            exports.sendNotification = functions.database
              .ref('/Notifications/{user_id}/{notifications_id}')
              .onWrite((event, context) => {

                   const user_id = context.params.user_id;
                   const notifications = context.params.notifications;

                  console.log('This User Id is :', user_id);
            });

【讨论】：