CODEWITHSUNDEEP
node.jsfirebasegoogle-cloud-functions
mailtester tester
mailtester tester

Reputation: 29

firebase functions showing error cannot read property previous of undefined

I had implemented firebase functions in my app and previously it was working fine but now it is showing error Cannot read property 'previous' of undefined

Error Logs of function

TypeError: Cannot read property 'previous' of undefined
at exports.LoveNotification.functions.database.ref.onWrite (/user_code/index.js:223:16)
at cloudFunctionNewSignature (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:109:23)
at cloudFunction (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:139:20)
at /var/tmp/worker/worker.js:730:24
at process._tickDomainCallback (internal/process/next_tick.js:135:7)

Upvotes: 1

Views: 1291

Answers (1)

Frank van Puffelen
Frank van Puffelen

Reputation: 600006

The signature of Cloud Functions triggers has changed. You seem to be using beta, but are deploying to the latest version. See the migration guide for complete instructions.

From there:

Before (<= v0.9.1)

exports.dbWrite = functions.database.ref('/path').onWrite((event) => {
  const beforeData = event.data.previous.val(); // data before the write
  const afterData = event.data.val(); // data after the write
});

Now (>= v1.0.0)

exports.dbWrite = functions.database.ref('/path').onWrite((change, context) => {
  const beforeData = change.before.val(); // data before the write
  const afterData = change.after.val(); // data after the write
});

So your code should look something like this:

exports.LoveNotification = functions.database.ref("/Member/{pushId}").onWrite((change, context) => {

 if (change.before.exists()) {
    return;
 } else {
    var eventLove = change.after.data.val();
    var author =eventLove.fullname;
    var title = eventLove.course;
    var key = eventLove.key;

    const payload = {
        "data": {
                    "post_id": key
                  },
        notification: {
            title: author +'Joined the app',
            body: `Course `+title,
            sound: "default",
            icon: "ic_launcher",

        }
    };

    const options = {
        priority: "high",
        timeToLive: 60 * 60 * 24 //24 hours
    };
    console.log('Sending notifications');
    return admin.messaging().sendToTopic("Member", payload, options);

    }
});

Upvotes: 2

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