I have a collection in my Firestore Database with posts. Each post has some comments as a document in the collection comments in the main post document (screenshot)
In my Android app when I click on the post item I go to PostDetail screen and there I download comments.
I want to increment the value of timesViewed for each comment which has been downloaded and displayed.
Is it possible to do that? I want to do that in the most efficient way. I don't want to increment every single comment manually by sending a request timesViewed++.
I want to increment the value of timesViewed for each comment which has been downloaded and displayed.
If you're looking for something that does that automatically, please note that there is nothing built-in.
Is it possible to do that?
Yes, but you should implement your own mechanism.
I don't want to increment every single comment manually by sending a request timesViewed++.
Unfortunately, there is no other way. However, it is very easy to implement. You can use FieldValue.increment(1).
Unfortunately, such a feature does not exist in the RealtimeDatabase firebase and firestore to automatically increase a field.
But you can create a counter and retrieve the counter every time onResponse () or onComplete and increase it by 1, which is not recommended for 2 reasons.
Generates extra traffic, especially if the number of users is large
It is not reliable because someone can intentionally increase it
But if you do not mind a lot of traffic and you insist on doing so, do not forget to set rules in the firebase console to control the incremental frequency.
Related
I am creating a rating system for my App. I have two collections.
Ratings and Items.
Every time a user rates an item, It goes inside the Ratings.
(e.g rating: 1)
What I want to do is every time someone rates an item, a cloud function will trigger that will get all the ratings and put it in the Items.
(e.g total_ratings: 400)
I've read something that I need to use Sharded Counter to have it right because there is a limit in writing in one document.
Increment counter with Cloud Functions for Firebase
But I've got no knowledge in node.js or how this Sharded Counter works. I can't understand how it works.
Can someone please help me how to do this? Thank you very much.
Working with Firebase for the first time and looking for advice of setting up the right structure for my project which is basically an "offers/coupon" type starter project.
The scenario is this:
I have a node containing a list of all offers available to users
This list of offers is displayed to users after successful Firebase authentication
When a user redeems an offer, I want to be able to count/record that activity in their child node under user and hide that offer so that they cannot see it again once used.
My question is what would be the best way to do this given that offers may be added, may expire, or may change at some point in the future. So, in effect, the user should receive the list of most updated offers, minus the ones he/she have used in the past.
a) would it be more effective to have a master list of offers, and then run a cloud/server function to clone this list for each new user an track that way
Firebase Structure 1
or
b) Keep a master list of offers in one node, then track user specific offer usage
Firebase Structure 2
Appreciate your guidance
The second solution is better because you'll save bandwith. This practice is called denormalization and is a common practice when it comes to Firebase. The first solution is not good becase every time you want to display the users you donwload unnecessary data. If you want to read more details about how you can structure a Firebase database in a efficient way, please read this post, Structuring your Firebase Data correctly for a Complex App. Also, you can take a look a this tutorial, Denormalization is normal with the Firebase Database, for a better understanding.
Second solution is much good. Because in first one we are having redundancy of data in our database. And second one obviously removing that cause.
But instead of using true or false because it is only showing you, "it's available or not", so you can use a string type parameter as "expired", "going to expire" and "updated" or whatever sooo. So it. Will be able to trace all you information related to offer for particular user. I think this is your requirement also.
Happy coding.
I have been looking for this quite some time now and i haven't found any answer related to my problem, so before you tag my question duplicate, at least read it first.
First i have just started firebase and only know basic things about it, i am trying to make a simple single user (1 to 1) chat app.
I want to get the number of users logged in in the database.
I have a child to the root of my database called users which have the list of the users who have logged in.
I know about the datashot.getchildrencount() but that works when some update/event happens, but i want it to give me the number of users whenever i want, not only on some event (For example in messenger number of current active users are shown continuously,i dont want active user tho, i just want total logged in users).
I thought of the another way to make a child called NumberofUsers so i store number of users there but then firebase dont allow to getvalue of the child,only set value (it does allow to get value but only on some event). Any idea what should i do?
UPDATE
i thought of another way to do this, though its not working at the moment but i think solving it is easier than thinking of another method to solve my original problem.
so I made one more child of NumberofUsers with key "02" and random value. now everytime i want data of "01" i change the value "02" after enabling the addChildEventListener for "NumberofUsers". Code that does this. Error its giving me. .new database.
Apparently I cant access child data using datasnapshot, any solution?
Any idea how to solve either of this?
Thank you.
Unfortunately, there is no way in which you can read data from a Firebase Database without attaching a listener. Regarding Firebase, everything it's about listeners. In your case, i think you want a callback to be called once and then immediately removed. If so, i recomand you using addListenerForSingleValueEvent() method to simplify this scenario. It triggers once and then does not trigger again.
This is useful for data that only needs to be loaded once and isn't expected to change frequently or require active listening.
Hope it helps.
I know this question a lot here, But I don`t know about this. This is about chat app.
When message get stored into the firebase database. It would become bigger and bigger as time goes by, I want to delete it. and when should I delete this? I just want to left just only last 10 data. It means if I out the app and again go in, It appears only last 10 sentence and I know about the function limitToFirst and limitToLast (but this is not the delete thing.)
If I pay firebase server, you know, if database's data is large It will be more expensive. but I just want to leave just last 10 sentences at least.
when they did come back then they can see the last 10sentence and want to delete except for this. how do I do this?
I saw the answer using the date, but I don`t want that. Is that only answer? If I must do that when I get to delete them? When do I invoke the delete function?
I know how to do that almost, but when? If in the app, there are so many friends and I open the chat screen to chat my friend. That time should I delete them using remove function? How am I saving this for server payment?
I don`t want cost a lot. and I want them to be clear, not dirty in my Firebase database console. so want to delete them. Which is the I have to do? Which time is the best time that I should delete them? When open it ? or when close it ? or when users stop the my app.
You can achieve this in a very simple way. You can use the getChildrenCount() method on the node in which you hold the messages to see the exact number of messages. If you are using as an identifier the random key generated by the push() method, it's very easy to delete the extra messages. Because the records are by default order by date, you can easily query your database using limitToLast(limit) method and than delete the messages like this:
yourRef.child("messages").child(messageId).removeValue();
Another way to achieve this is to use Cloud Functions for Firebase.
Hope it helps.
you can use firebase functions to delete old data when new ones added to the database that is the best time, you can keep the last 100 messages or less.
I currently have several fragment tabs , each with a feed of user statuses, being I have about a 100 other users posting from their accounts there is constantly new data every few minutes. currently the users only choice is to switch fragments back and fourth to get the entire fragment to reload which sends another http request and returns the new data as well as all the old data the user already had. it just doesnt seem efficient, know there has to be a better way. Can someone give me a overview of the most efficient way to keep this data fresh without having the user switch tabs back and fourth?
Is this where using sqlite and/or services comes into play?
Though some developers and designers argue between if content should be refreshed automatically of not, I argue content like streams shouldn't be refreshed automatically unless you are expecting very less incoming data.
I have used twitter4j to stream tweets and refresh automatically in one of my test app, twitter4j has a listener that lets you know when new tweets are received. First I pushed data into ListView as soon as new feeds were received and it was kind of flashy but, efficient. Then I queued up data until it reached certain threshold and pushed data into ListView, it was bit better. I thought it was good enough but, when I monitored my "Data Usage", i quite realized why I shouldn't refresh automatically.
Now here are some example implementation:
(Suggest) Do some type of polling or I recommend you to implement
push(like GCM) to let your client-side know that there's new content
in the server.
(Option) Use SyncAdapter with server triggered sync
(Recommend) Let user be in control, it's more than okay to use
Pull-to-Refresh pattern like Facebook or ActionBar sync button like
Google+. It will not make UserExperience any bad.
Now here's how your sample request API should be like or you can match your own config:
{
"fromIndex": 0,
"toIndex": 10
...
}
well, i'll try to give you a general overview to see if you can get it without the need of getting into deepest details, an idea it just came to my mind:
1- you need to configure your server to retrieve from an "specific" point of the content or retrieve a token that you will pass to the server (on next HttpRequest) to know from where part of the content or from where "index" start to send the content again.
2- you need to have a Listener (i dont know how you are showing your data but this is the case of a ListView) that tells you when the user is closely to get to the end of the ListView and let't say if there are already 10 elements, in element 7 the Listener should call the method to get more content from the server.
3- Yes, you need to keep the data already retrieve in SQLite temporarily, you can't use SharedPreference to keep it because it probably would be a lot of data and maintain it in memory could be a bad idea, writing a file is not an option here neither, so SQLite is your best friend in this case.
Maybe there would be more problems specifics about what you are trying to achieve but to me in a general perspective, those 3 points should at least help you in the direction to go.