I'm working on project that sell unique soft products like serials or tickets. To be fast and reliable, we going to use Firebase Real-time Database.
The problem is I want to remove or update the sold ticket after the user get it.
One way to do so is using another server to do so manage the tickets and update the Firebase Database using REST API, but I want to do it with the Firebase only.
Another way to do it, after the user get a ticket, the client side app will sent a remove request. But I'm afraid of losing the data in the middle of this process. A user got a ticket but never removed from the database. As I said the ticket is unique.
How to do it with Firebase side only?
Related
I’m planning on abuilding a nextjs app and connecting it to a DB. I’d like users to login to their profiles where a summary of their calendly charged sessions through stripe is visible in a table format.
What would be the best way to get this done? I know both stripe and calendly have their own APIs to pull the data in but how can I connect them to save records in DB for a user with a unique email and ID?
Your question is too general. I think this is due to a lack of information about Stripe's features. To narrow down the problem, I'd recommend to start from Usage-based pricing. This will allow you to understand what data structure you will have in Stripe and what part of it you want to store in your database. So, in general you should pass session time from Calendly to Stripe. I don't know how it is in Calendly, but for Stripe, an email is not a unique identifier. Thus, ensuring uniqueness is up to you.
I am building a job portal for the web using React, Redux and Firebase/Firestore. I've completed all the features I needed except one.
I want unregistered-users/job-seekers to be able to:
Bookmark job posts.
Keep the record of applied jobs.
Keep the record of search queries.
I am thinking about using IndexedDB for this feature. Particularly Dexie.js to make things easier. However, this data will be persisted in user's browser and user will have no access to it in another browser or device. Therefore, I want to give users an option to be able to save all the data to Firestore if user sign into the website and I need this to be automatic. So, as soon as user signs in, I will save it to the database.
I thought about using Anonymous Authentication instead of IndexedDB/Firestore, so all the data will be saved into the database and as soon as user signs in using credentials, the user can claim the ownership of the data. However, this is an extra step to use these features I listed above and not everyone is happy with authenticating an app even though nothing is required from the user. Besides, there will be so many ghost accounts.
So, as I mentioned in the title; I want to save everything to IndexedDB (I will take care of this), but how am I going to synchronize all the data in IndexedDB to Firestore as soon as user signs in?
I imagined the basic process will be like this:
User clicks "Bookmark Job Post"
App checks if users is authenticated or not.
If authenticated, save the bookmark to the Firestore.
If not authenticated, save the bookmark to the IndexedDB.
If User decided to sign in or sign up, check IndexedDB and synchronize it with Firestore and clear IndexedDB.
How can I achieve the 5th step technically? Is there any built in system in Firebase? Also, please feel free to share your idea if you can think of another way implementing this feature. Should I be using firebase.auth().onAuthStateChanged() for the 5th step?
And lastly, how should I structure the Firestore to save bookmarked jobs, applied jobs and search history?
Should I create a bookmarkedJobs collection and have documents of jobPosts duplicated for each user, who bookmarked the job post? And every time a job post is updated by an employer, I will have a cloud function going through bookmarkedJobs collection, updating every instance of it?
Thank you
This may be of interest to you
https://dexie.org/docs/Syncable/Dexie.Syncable.js
Been looking into making my website fully static/pwa, and just using indexeddb, and some webservice for data handling/storage ..this seems like a interesting route to explore.
In my Android application I have an idea to store in database some serial key. If user enters correct key he gets full version of application and the key is disabled on the server to avoid multiply usage of the same key, otherwise he can buy app in Google Play without a key.
For this I thought to use Firebase Database but after read this I have some doubts
Firebase Realtime Database
Store and sync data with our NoSQL cloud database. Data is synced across all clients in realtime, and remains available when your app goes offline.
Does it mean that firebase will duplicate the table with all available keys to all application users and some smart user can read the list from this copy at his phone?
Not all data is automatically duplicated to all clients. Only data that the client subscribes to is received by that client.
You can control what data each client can see through Firebase's server-side security rules. For example, you'll typically want to ensure that each user can only read their own data.
It probably isn't a good idea to store super-sensitive data like social security numbers or credit card numbers, but if you see https://firebase.google.com/docs/database/security/ you can see, that you can control access to data, & use validation, especially since you can regenerate the keys if they become compromised, it wouldn't be the worst option. If you look at https://firebase.google.com/docs/database/security/user-security you can see, that it's possible to write an app that uses it like google drive with a smartphone-based client.
Personally the answer would no. You may want to think about Google Play Subscriptions and In-App Purchases.
If you really have to then:
Create a key as a user buys the upgrade (server-side).
Store the device id/account id (hashed) and timestamp with the key.
Credit card details and expiry dates should be combined into one hash.
Just encrypt everything.
It's better to have a banned list than a list of approved key. Eventually you have to create more keys and it's easier just to maintain a list of banned keys.
this is a bit of a composite question, I'll try my best to separate the various parts even if they all have a common intent.
Common intent
Having a clear way of delivering notifications about posts regarding specific topics to Firebase Users (and not simply to application instances).
I have tried various methods, and I can't find a definitive answer about which one is the best one.
Method 1 - Relying only on the database
Each Firebase User has its own document in the Firestore at users/{userId}
This document contains two collections: tokens and interests.
The token collection contains a list of documents which have FCM tokens as one of their fields. Each time an user signs in the application or FirebaseInstanceIDService.onTokenRefresh() is called, the collection is updated to add the new token.
The interest collection contains a list of interests which simply are strings and are used as tags for posts. This collection has a mirror as interests/{interestId}/users/{userId} showing all the users interested in something. (This is kept updated and synchronised via a Cloud Function)
When a new post is created under a specific interest, I can get a list of all the users interested and then get their tokens from their document. Finally, I send a notification to each individual token.
Problems
This solution is not elegant (this isn't that big of a problem)
With the new GDPR rules I fear I might not be allowed to save tokens
directly on the Database
If the user signs out when he's offline, the
token isn't removed from his document, and the new user receives
notifications for the old interests.
Should I keep track of what the current token is and update it each time an user signs in ignoring FirebaseInstanceIDService.onTokenRefresh()? Else only the user signed in when the service is called would update the database.
Method 2 - Using FCM topic subscriptions
This should be the best option for me, but I can't understand how to make it work with multiple users on the same phone (always one at a time though)
The way I would handle this is still have the users/{userId}/interests collection, removing users/{userId}/tokens and interests/{interestId}/users, and subscribe/unsubscribe from the various topics as the user signs in and out.
Problems
What happens if the user signs out when he's offline? There is no way to retrieve the current subscriptions and remove each one, potentially resulting in conflicting topics subscriptions.
Thank you very much for your time
I'm trying to get started implementing Web Push in one of my apps. In the examples I have found, the client's endpoint URL is generally stored in memory with a comment saying something like:
In production you would store this in your database...
Since only registered users of my app can/will get push notifications, my plan was to store the endpoint URL in the user's meta data in my database. So far, so good.
The problem comes when I want to allow the same user to receive notifications on multiple devices. In theory, I will just add a new endpoint to the database for each device the user subscribes with. However, in testing I have noticed that endpoints change with each subscription/unsubscription on the same device. So, if a user subscribes/unsubscribes several times in a row on the same device, I wind up with several endpoints saved for that user (all but one of which are bad).
From what I have read, there is no reliable way to be notified when a user unsubscribes or an endpoint is otherwise invalidated. So, how can I tell if I should remove an old endpoint before adding a new one?
What's to stop a user from effectively mounting a denial of service attack by filling my db with endpoints through repeated subscription/unsubscription?
That's more meant as a joke (I can obvioulsy limit the total endpoints for a given user), but the problem I see is that when it comes time to send a notification, I will blast notification services with hundreds of notifications for invalid endpoints.
I want the subscribe logic on my server to be:
Check if we already have an endpoint saved for this user/device combo
If not add it, if yes, update it
The problem is that I can't figure out how to reliably do #1.
I will just add a new endpoint to the database for each device the user subscribes with
The best approach is to have a table like this:
endpoint | user_id
add an unique constraint (or a primary key) on the endpoint: you don't want to associate the same browser to multiple users, because it's a mess (if an endpoint is already present but it has a different user_id, just update the user_id associated to it)
user_id is a foreign key that points to your users table
if a user subscribes/unsubscribes several times in a row on the same device, I wind up with several endpoints saved for that user (all but one of which are bad).
Yes, unfortunately the push API has a wild unsubscription mechanism and you have to deal with it.
The endpoints can expire or can be invalid (or even malicious, like android.chromlum.info). You need to detect failures (using the HTTP status code, timeouts, etc.) when you try to send the push message from your application server. Then, for some kind of failures (permanent failures, like expiration) you need to delete the endpoint.
What's to stop a user from effectively mounting a denial of service attack by filling my db with endpoints through repeated subscription/unsubscription?
As I described above, you need to properly delete the invalid endpoints, once you realize that they are expired or invalid. Basically they will produce at most one invalid request. Moreover, if you have high throughput, it takes only a few seconds for your server to make requests for thousands of endpoints.
My suggestions are based on a lot of experiments and thinking done when I was developing Pushpad.
Another way is to have a keep alive field on you server and have your service worker update it whenever it receives a push notification. Then regularly purge endpoints which haven't been responded to recently.