I'm working on an app where I need to show the friend's presence ( not all users ), as you can see in the picture below. I read the docs of Firebase, they mentioned about users presence but they don't mention any thing about this scenario. If I use all users presence method then what will I do if the users are more than 1000? it gets the data downloaded on every change which I don't want.
There is an idea if I add multiple listeners for every friend then it will be efficient or not, if not then what will be the best practice for it.
Thanks
Related
I am trying to create a basic app for my small educational business.
We supply English teachers to schools and I want a way for parents to access the progress reports and other data about their children.
I'm using Android Studio and Flutter as well as Firebase to store the data. I don't want parents to be able to access the data of every child, obviously, but they may have more than one child at the school.
So I need to limit their read privileges to just the records that relate to their children. I'd like to do that by giving them some sort of registration code that they could use the first time they access the app so that we can ensure that they are only being given access to the correct records. Subsequent logins would then be via email and password.
Is there a way to do this with Firebase?
Your use-case sounds feasible, but it is really broad which makes it impossible to answer it completely-yet-succinctly.
Specific on what to do with the registration code that associates a parent with their children, when you generate the registration code, you write that code and the associated children to a database. Then when the parent registers with that code, you associate their account (UID) with the code. You'll just have to ensure that the code is sufficiently long and random that it can't be reasonably guessed by another user.
I am working on a video based app that keeps track of how many views that video has received. I originally planned on having a field for view_count in my document that I would write to after someone watches a video.
However, knowing how many writes that could end up leading to, I started to wonder if it's possible to see a breakdown of how many reads have been made for each document in a collection and use that number instead. Since the videos are short, I figured this would be an accurate number for the view count.
Is this possible to access this kind of data?
Firestore does not expose any per-document access metrics. The available monitoring options are shown on this page on monitoring usage.
If you want something beyond that you'll have to build it yourself, as you originally intended.
So I have a Firestore database where i have all my posts in, I push them on page load into the store so I can have a fast navigation and only need to fetch once.
What I wanna do now is to use a persisted state so i dont need to refetch it if the user opens a new window or F5(reloads) the page.
The problem is im not sure how to check if new Posts are in the Firestore without querying all posts and I havent found any methods to do it in a healthy and Read efficient way.
There's no super easy way around it - at the end you have some data, and the server has another, you need to check for differences.
If you're only trying to figure out if there are new posts on the backend, which are not loaded on your frontend, then just get the date on your last post, and then ask Firebase for all posts after this date :)
Of course if you don't have posts, ask for everything.
Keep in mind you need to manually check if posts are deleted ;)
Realtime updates with the onSnapshot method can be used to keep local data in sync with the server. If you initially load it into vuex then subsequent changes on server side will be reflected automatically.
https://firebase.google.com/docs/firestore/query-data/listen
To share one set of data across tabs/windows you could look at something like this
https://github.com/xanf/vuex-shared-mutations
coming from a SQL background I am still getting used to Firebase.
If I have a node for customers and I allow Firebase to create an id by using the "push" method, how do I take a customer and then only push if it doesn't already exist with the same email address and if it does, then update it?
I know set will create or update if I have a specific node (ie each node is identified by, say, the email address) but in this case I want to push if it doesn't exist and presumably set if it does. What's the neatest syntax for doing this?
thanks
Phil
First, Firestore is recommended for projects going forward. More features.
Note that firebase auth has this email duplication functionality baked in already. So, you might be spending effort on a feature that is already done for you. See auth/account-exists-with-different-credential
Finally to answer your specific question:
The way I do that is to chain the write after a read (.then). The read seeks to fetch the node. After the read if whatever field exists or === myString then you know it's already there.
If I have User and Profile objects. What is the best way to structure my collections in firestore given that the follow scenarios can take place?
Users have a single Profile
Users can update their Profile
Users can save other users' profiles
Users can deleted their saved profiles
The same profile can't be saved twice
If Users and Profiles are separate collections, what is the best way to store saved profiles?
One way that came to mind was that each user has a sub collection called SavedProfiles. The id of each document is the id of the profile. Each saved Profile only contains a reference to the user who's profile it belongs to.
The other option was to do the same thing but store the whole profile of each saved profile.
The benefits of the first approach is that when a user updates their own profile there's no need to update any of the their profiles that have already been saved as it's only the reference that is stored. However, attempting to read a user's saved profiles may require two read operations (which will be quite often), one to get all the references then querying for all the profiles with those reference (if that's even possible???). This seems quite expensive.
The second approach seems like the right way to go as it solves the problem of reading all the saved profiles. But updating multiple saved profiles seems like an issue as each user's saved profiles may be unique. I understand that it's possible to do a batch update but will it be necessary to query each user in the db for their saved profiles and check if that updated profile exists, if so update it? I'm not too sure which way to go. I'm not super used to NoSQL data structures and it already seems like I've done something wrong since I've used a sub collection since it's advised to keep everything as denormalized as possible so please let me know if the structure to my whole db is wrong too, which is also quite possible...
Please provide some examples of how to get and update profiles/saved profiles.
Thank you.
Welcome to the conundrum that is designing a NoSQL database. There is no right or wrong answer, here. It's whatever works best for you.
As you have identified, querying will be much easier with your second option. You can easily create a Cloud Function which updates any profiles which have been modified.
Your first option will require multiple gets to the database. It really depends how you plan to scale this and how quick you want your app to run.
Option 1 will be a slow user experience, while all of the data is fetched. Option 2 will be a much faster user experience, but will requre your Cloud Function to update every saved profile. However, this is a background task so wouldn't matter if it takes a few seconds.