使用Firebase云消息发送通知

Question

I'm trying to send notification to users with firebase cloud messaging when they are being sent friend request in my app using the below function which i deployed to my firebase functions

 '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); }); 

but when it trys to send the notification, i get the following error in my functions logs

  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) 

Answer 1

you have to add context and get the parameter from there. Try:

            ..'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);
            });