How to sync IndexedDB with Firestore? - firebase

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.

Related

How to save user data in db, without logging in?

I am working on a simple app that allows users to search for something using an API and save it to view later.
However, I don't want to integrate authentication in the app. I can, but would rather not as a UX decision. Do you know of a way to generate a device token, that is unique to every device and can be used to store which assets a device has saved in the db?
I am thinking of expo push tokens as a possible solution, but that would require users to accept push notifications - so what happens if a user says no?
Sounds like you could just use react-native-uid to generate a unique id for your device and then store it in AsyncStorage and fetch it from there going forward.
For more inspiration, or perhaps just a more canonical way to do this... read up on suggestions surroundings the recently deprecated constant for installationId here:
https://docs.expo.dev/versions/latest/sdk/constants
I haven't used this before but if you're looking for something bullet proof then this is probably your goal of getting the same concept.
Firebase Anonymous Authentication might be ideal to use in this case. This can be used to create a user in Firebase auth without any credentials and can be useful especially when you are using either of Firebase's databases since you can use security rules with user's UIDs.
However, once the user logs out of the account by any means including but not limited to using sign out option in your app, clearing app data or uninstalling the app, the same account with that UID cannot be recovered. I looked up for AsyncStorage and apparently that gets cleared to if the app is deleted.

Problem with reading user data of an app developped with Firestore

I have been introduced to Firebase a few days ago. Since then I have been trying to discover more features and usage of Firebase, in particular, the usage of the Firestore/Realtime Database.
However, as I am reading into more details, I start to think of some questions. I hope someone that is familiar with Firebase can help me answer them
As for User authentication, I understand that I can use Firebase Authentication where I won't see their real password. However, technically, everything that user stores in my Firestore would be visible to me since I am the owner of the Firebase.
For example, if I were to develop a note/chat app, in which the user can access their notes/chat on the iOS app and also Android. That means all their notes data would be saved in my database. If it happens to contain some private data, then I would be able to read it?
Even if I set security rules, that would be only facing client-side, whereas, for me, the owner of the entire firebase data, I could see the whole thing. Surely, as a customer, you won't want to use an app knowing that I can see everything you write
I am not sure if what I said is true or not. If true, is there a possible solution?
Both of your statements are correct. This happens in most of the apps-websites, the admin or some core developers have full access to the data. That's why privacy policy and GDPR exist. You must specify what data you collect and for what reason. If you intend to use your user data for any other reason you must inform them. Be aware that if you disclose any user information without his permission you can be held liable.

Flutter: offline local storage syncing with online e.g. firebase

Is this a common/reasonable Use case?
An app allows a user to save favorites locally so that the user doesn't need to signup.
Then the user afterwards desires to share their favorites.
Therefore favorites data needs to be synced from local to remote. The usual local storage for flutter is sqflite, and firebase/store is the remote. However, this seems cumbersome, as sql to nosql conversion is necessary.
I thought that this would be a general issue for UX etc, but I can't find any discussion of this issue? Maybe forcing the user to create an account is the most general solution?
It's a common understanding that if you don't have user account then you can't have any user data associated with your name. You don't have to force the user to have an account or lock them out.
When they favourite something just show a dialog telling them "If you don't have an account your favourites are stored on the device only. If you want your favourites to be available everywhere please create an account" then show options for "Create account" or "No, Thanks"
Create account: Goes to account creation page
No, Thanks: Adds the device to the favourites list and lets the user continue to do what your app does.
There's no problem to solve here from what I'm seeing. If you don't have an account you don't get account functionality. If you track users without them entering anything it's also a little bit illegal and creepy so no need to push the limits on how you can track the same user.
Another way to think of it is to make signup so easy they don't mind and also guarantee that it's worth it. Won't be used for spam or information selling. Take what's app as an example, even though you need to mobile number to send the messages, it's just used as a unique identifier and has nothing to do with the device's number.
Ask for their phone number or email or just any email, you'll most likely get fake info.
And what does your analytics say? Are you getting requests from users saying they lost all their information on a different device? How many people are using your favourite functionality?
I may have come to the party a little late here but here's my 2 cents worth.
The Sql to NoSql conversion is not cumbersome. In fact, there is a reasonable use case for this. I have the same requirement for an app that I am about to build.
Anyway, to store data in RDMDB or NoSQLDB you will need a data model to ensure consistency in your app. If the user has been using the app offline, and they later choose to go online, you can allow them to create the Remote Account, then check if they have local favorites. If they do, you will HAVE to ask them if they'd like to import them into the remote storage. If they choose to do so, you will then have to read their favorites from the local storage and store them in a List<Model> then map() that back to the online storage.
NoSqlDB can accept the json type data, so your model should include the conversion fromMap() and toJson() for this purpose (and others).
When I have come around to doing this, I will share my code (if I remember to come back here).

Understanding the Firebase and purpose of google cloud functions

Let's say I'm developing app like Instagram: for iOS, Android and Web. I decided to use Google Firebase as it really seems to simplify the work.
The features user needs in the app are:
Authorization/Registration
Uploading photos
Searching for other people, following them and see their photos
I come from traditional "own-backend" development where I do need to setup a server, create database and finally write the API to let the frontend retrieve the data from the server. That's the reason why it's unclear to me how it all works in Firebase.
So the question is how can I create such app:
Should I create my own API with cloud functions? Or it's ok to work with the database directly from the client-side?
If I work with the database directly why do I need cloud functions? Should I use them?
Sorry for such silly questions, but it is really hard to get from scratch.
The main difference between Firebase and the traditional setup you describe is that with Firebase, as far as the app developer is concerned, the client has direct access to the database, without the need for an intermediate custom API layer. Firebase provides SDKs in various languages that you would typically use to fetch the data you need / commit data updates.
You also have admin SDKs that you can use server-side, but these are meant for you to run some custom business logic - such as analytics, caching in an external service, for exemple - not for you to implement a data fetching API layer.
This has 2 important consequences:
You must define security rules to control who is allowed to read/write at what paths in your database. These security rules are defined at the project level, and rely on the authenticated user (using Firebase Authentication). Typically, if you store the user profile at the path users/$userId, you would define a rule saying that this node can be written to only if the authenticated user has an id of $userId.
You must structure your data in a way that makes it easily readable - without the need for complex database operations such as JOINs that are not supported by Firebase (you do have some limited querying options tough).
These 2 points allow you to skip the 2 main roles of traditional APIs: validating access and fetching/formatting the data.
Cloud functions allow you to react to data changes. Let's say everytime a new user is created, you want to send him a Welcome email: you could define a cloud function sending this email everytime a new node is appended to the users path. They allow you to run the code you would typically run server-side when writes happen, so they can have a very broad range of use-cases: side-effects (such as sending an email), caching data in an external service, caching data within Firebase for easier reads, analytics, etc..
You don't really need a server, you can access the database directly from the client, as long as your users are authenticated and you have defined reasonable security rules on Firebase.
In your use case you could, for example, use cloud functions to create a thumbnail when someone uploads a photo (Firebase Cloud Functions has ImageMagick included for that), or to denormalize your data so your application is faster, or to generate logs. So, basically you can use them whenever you need to do some server side processing when something changes on your database or storage. But I find cloud functions hard to develop and debug, and there are alternatives such as creating a Node application that subscribes to real time changes in your data and processes it. The downside is that you need to host it outside Firebase.
My answer is definitely NOT complete or professional, but here are the reasons why I choose Cloud Functions
Performance
You mentioned that you're writing an instagram-like mobile device app, then I assume that people can comment on others' pictures, as well as view those comments. How would you like to download comments from database and display them on users' devices? I mean, there could be hundreds, maybe thousands of comments on 1 post, you'll need to paginate your results. Why not let the server do all the hard work, free up users' devices and wait for the results? This doesn't seem like a lot better, but let's face it, if your app is incredibly successful, you'll have millions of users, millions of comments that you need to deal with, server will do those hard jobs way better than a mobile phone.
Security
If your project is small, then it's true that you won't worry about performance, but what about security? If you do everything on client side, you're basically allowing every device to connect to your database, meaning that every device can read from/write into your database. Once a malicious user have found out your database url, all he has to do is to
firebase.database().ref(...).remove();
With 1 line of code, you'll lose all your data. Okay, if you say, then I'll just come up with some good security rules like the one below:
This means that for each post, only the owner of that post can make any changes to it or read from it, other people are forbidden to do anything. It's good, but not realistic. People are supposed to be able to comment on the post, that's modifying the post, this rule will not apply to the situation. But again, if you let everybody read/write, it's not safe again. Then, why not just make .read and .write false, like this:
It's 100% safe, because nobody can do anything about anything in your database. Then, you write an API to do all the operations to your database. API limits the operations that can be done to your database. And you have experience in writing APIs, I'm sure you can do something to make your API strong in terms of security, for example, if a user wants to delete a post that he created, in your deletePost API, you're supposed to authenticate the user first. This way, 'nobody' can cause any damage to your database.

session vs profile to store userID in an extremely simple vb.netapp

I am building an extremely simple VB.net web application that uses Visual Studio's forms authentication. As part of this- I am trying to capture the userID upon login and use it while the user is in the app (to dynamically display information via dataset/gridview that is associated with that userID) so I don't have to give them their userID and prompt them for it constantly.
The app is very simple and uses a local DB to do all the authentication (Users, User_Activation, Roles)
This app will have 9-10 users that will be consistent over the years(logging in 10-15 times a year), and 40-50 rotating users that log in once or twice and do not return past that year.
The profiles and authentication/sessions do not need to handle tons of users and authentication requests.
I also want to avoid cookies because I want to keep everything as simple, and centralized to the application as possible.
I have explored building a GetUserID function that queries the database based on the userName every time a user takes an action (button click, page load) that requires the userID. But I am having trouble with the SQL and it seems bulky.
I have also looked into sessions- but they seem unreliable and difficult to manage.(How do i keep each session separate as users login?)
I am now looking at Profiles
https://msdn.microsoft.com/en-us/library/2y3fs9xs.aspx
https://msdn.microsoft.com/en-us/library/system.web.profile.sqlprofileprovider.aspx
I think I can just use the default instance of the SqlProfileProvider and point it to my database I already have built?
I am very new to programming and am not sure how complex the configuration would be for the Profiles, so any guidance or advice would be greatly appreciated!
I can post any code snippets needed, or upload the app to github or something if that helps at all.
Thanks!

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