Htykuut

what I am trying to do is I have a messages app made in Swift and I'm using Firebase as my database. What I'm trying to do is to have the functionality of disappearing messages like in Snapchat; however, I'm not exactly sure how I should to that. I have a timestamp on the message in the database, but I'm not sure how to use it. This is what I'm trying to do, I just don't know the exact code for it.

Here is a picture of what my database structure looks like. Let me know if you need any more information. Thank you

I would suggest managing your timestamps in Firebase by the metric of milliseconds since January 1st, 1970, by using NSDate().timeIntervalSince1970 * 1000 in Swift and then Date().getTime(); in your cron job written in JavaScript. You can store let date = Int64(NSDate().timeIntervalSince1970 * 1000) under your date node in firebase for each of your posts when they are created. Then you can create a cron job using Firebase Functions and Google Cloud that runs every hour that queries the posts and deletes posts with date timestamps more than a day old.

Here is a great tutorial on how get started with cron: https://firebase.googleblog.com/2017/03/how-to-schedule-cron-jobs-with-cloud.html

Your cron job will need to be coded in node.js and will look something like this:

// example cron job after setting everything up in the tutorial

    exports.hourly_job =

        functions.pubsub.topic('hourly-tick').onPublish((event) => {

        // get current date and time

        var currentDate = new Date();

        console.log("Hourly Deletion Ran at: " + currentDate);

        var currentNumMilliseconds = currentDate.getTime();

        // remove a days worth of time

        var oneDayAgo = currentNumMilliseconds - (3 * 24 * 60 * 1000);

        var cutoffDate = new Date(oneDayAgo);

        console.log("Query start at date: " + oneDayAgo);

        // the firebase database ref where your posts are stored

        const ref = admin.database().ref('posts');

        // query all posts more than a day old

        ref.orderByChild('date').startAt(oneDayAgo).once('value').then(function (snapshot) {

            // for each snapshot returned from the query that is older than one day, delete

            snapshot.forEach(function(childSnapshot) {

                var key = childSnapshot.key;

                var postObject = childSnapshot.val();   

                ref.child('key').remove();

            });



        });

    });