Making a leaderboard with Firebase Realtime database and Unity

Question

I am making a leaderboard by using firebase realtime database, unity and facebook ( for profile pic and name )

But I am struggling, I am not sure about the way of doing that. I want to display multiple leaderboards -> All time WORLD / REGION / FRIENDS score, monthly WORLD / REGION / FRIENDS and weekly one.

I know I can use cloud functions to reset weekly and monthly leaderboards. But how can I store world and region scores ? Now I just have this ->

https://cdn.discordapp.com/attachments/440873502535450627/821361474353889320/ld.JPG

Thanks to that, I can easily get region leaderboards getref.getchild users . getchild france and then orderbyvalue . limittolast ! this is good !

The problem is how could I get world leaderboard ? ( I have other countries ) I am so lost...Do I need to make another structure for my leaderboard ?

Answer 1

There are a number of considerations that you might put into this including pricing, how much you trust the client, &c. Generally, with a NoSQL database like Realtime Database, you might have a lot of redundant data to make up for the fact that your ability to query is limited. It's also really easy to pull in a lot of data by mistake, so you'll see a number of best practices around keeping your database shallow.

With that said, I think I might recommend reorganizing your data a little bit. For example: Have one node named "users" with all of your users in there. Each "user" in users should be placed in a node that's simply the userid (which makes security rules easier to write), and here you can place the all time score, monthly score, and weekly score. I'd also recommend storing the time you got that score (using ServerValue.Timestamp) so you don't have to worry about going through your users and deleting all the old scores. If your weekly timestamp isn't this week, you know to ignore/overwrite it (obviously, time is hard, so you'll have to work out what a "week" means to players of your game wrt time zones &c). I'd also put an array of all a user's "friends" under this user node by their user id. That way, when you go to look up friends, you just just ask for "users/" explicitly there.

Now for regional and world leaderboards on monthly and weekly cadences, I'd just copy everything you want to display into that leaderboard node (say username and score) and add the uid if you need to attribute it back to a user (say if you want to click on that score and see their all time record). So if a user lives in France and they get a weekly high score for them, I'd first write that user's "users/" node with the weekly score and timestamp, then I'd go out to the weekly leaderboard for France and add the new score if it qualifies (ie: don't add it if you're only tracking the top 10), then go out to the world leaderboard and add it there.

How you do this copying is up to you. You could make it the client's responsibility with security rules just making sure they're well behaved - which would probably be fast and cheap but might get weird if they go offline partway through updating. You could use a Firebase trigger that would listen for a user updating their node and copy the data out to the respective leaderboards (this would be more expensive since you're paying for Cloud Functions time and a bit slower but will always work once the user node is updated).

A final note is that for, say, weekly leaderboards. I'd have a node that says "this is France's weekly leaderboard right now" and have all clients read that first before figuring out where to write. That way, at a time you decide for when the week turns over, you can change that node and just have people start writing somewhere else. You can then keep the old leaderboard up for some time (ex: maybe you want to see who changed between this week and last), and you can delete it at your leisure after you're sure that all players have their score in (ex: over slow internets, disconnects, &c).