sending email through firebase triggers using sendgrid - node.js

Question

I am sending email to user using onCreate trigger in firebase.I am using sendgrid templates for sending emails. when a new document is created in the firestore it should trigger the email to the user.
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
const sgMail = require('#sendgrid/mail');
const SENDGRID_API_KEY = 'SG.ivqQZKFcSdqONZZ7IRtkjA.1RdSs50..kBaQ';
sgMail.setApiKey(SENDGRID_API_KEY);
exports.firestoreEmail = functions.firestore
.document('userAccount/{userId}')
.onCreate(event => {
const userID = event.params.userId;
if (userID === undefined) {
console.log('userID DOES NOT EXIST')
// This was a deletion event, we don't want to process this
return;
}
else{
console.log(userID )
return db.collection('userAccount').doc(userID)
.get()
.then(doc => {
const user = doc.data()
const msg = {
to: 'lekha.saraf#nexivo.co',
from: 'lekhasaraf09#gmail.com',
subject: 'NewFollower',
templateId: '8...............d760e',
substitutionWrappers: ['{{', '}}'],
substitutions: {
name: user.UserName
// and other custom properties here
}
};
return sgMail.send(msg)
})
// .then(() => console.log('email sent!') )
} // .catch(err => console.log(err) )
});
The error I am getting is:
TypeError: Cannot read property 'userId' of undefined

Answer 1

You have 2 parameters from the .onCreate() method. A snapshot from the created document and the event.
exports.firestoreEmail = functions.firestore
.document('userAccount/{userId}')
.onCreate((documentSnapshot, event) => {
const userID = event.params.userId;
const documentData = documentSnapshot.data();
I do not know if the event.params.userId works for Firestore.
If you need the userId from the user which created the document you could use const userID = event.auth.uid.
If you need the userId from the user you will send the mail to you should write the userId in the document.