Develop Reference

Is there anyway i can update a firestore document automatically even if app is closed, is there a listeener or something

i have a firestore and project that needs to be updated automatically without user interaction but i do not know how to go about it, any help would be appreciated. take a look at the json to understand better
const party = {
id: 'bgvrfhbhgnhs',
isPrivate: 'true',
isStarted: false,
created_At: '2021-12-26T05:20:29.000Z',
start_date: '2021-12-26T02:00:56.000Z'
}
I want to update the isStarted field to true once the current time is equal to start_date

I think you will need Firebase Cloud Function, although I don't understand exactly what you mean.
With Cloud Functions, you can automatically run (add, delete, update, everything) codes on Google's Servers without the need for application and user interaction.
For example, in accordance with your example, it can automatically set "isStarted" to true when it hits the "start_date" time. If you want to code a system that does not require user interaction and should work automatically, you should definitely use Cloud Functions. Otherwise, you cannot do this on the application side.
For more info visit Cloud Functions

Ok, I managed to find a workaround to updating my documents automatically without user interaction since the google billing service won’t accept my card to enable cloud functions for my project, I tried what I could to make my code work and I don’t know if other peeps would follow my idea or if my idea would solve similar issues.
What I did was that in my nextjs file I created an API endpoint to fetch and update documents after installing the firebase admin SDK, so I fetched all documents and converted all start_date fields in each document to time and checked for documents whose start date is less than or equal to current date, so after getting the document, I ran a firestore function to Update the document.
Tho this will only run when you make a request to my domain.com/api/update-parties and never run again
In other to make it run at scheduled intervals, I signed up for a free tier account at https://www.easycron.com and added my API endpoint to EASYCRON to make requests to my endpoint at a minute interval, so when the request hits my endpoint, it runs my code like other serverless functions😜. Easy peezy.

Best way to have a Node.JS server keep updated with a FireBase database in real time?

I currently have a Node.JS server set up that is able to read and write data from a FireBase database when a request is made from a user.
I would like to implement time based events that result in an action being performed at a certain date or time. The key thing here though, is that I want to have the freedom to do this in seconds (for example, write a message to console after 30 seconds have passed, or on Friday the 13th at 11:30am).
A way to do this would be to store the date/time an action needs be performed in the database, and read from the database every second and compare the current date/time with events stored so we know if an action needs to be performed at this moment. As you can imagine though, this would be a lot of unnecessary calls to the database and really feels like a poor way to implement this system.
Is there a way I can stay synced with the database without having to call every second? Perhaps I could then store a version of the events table locally and update this when a change is made to the database? Would that be a better idea? Is there another solution I am missing?
Any advice would be greatly appreciated, thanks!
EDIT:
How I currently initialise the database:
firebase.initializeApp(firebaseConfig);
var database = firebase.database();
How I then get data from the database:
await database.ref('/').once('value', function(snapshot){
snapshot.forEach(function(childSnapshot){
if(childSnapshot.key === userName){
userPreferences = childSnapshot.val().UserPreferences;
}
})
});

The Firebase once() API reads the data from the database once, and then stops observing it.
If you instead us the on() API, it will continue observing the database after getting the initial value - and call your code whenever the database changes.

It sounds like you're looking to develop an application for scheduling. If that's the case you should check out node-schedule.
Node Schedule is a flexible cron-like and not-cron-like job scheduler
for Node.js. It allows you to schedule jobs (arbitrary functions) for
execution at specific dates, with optional recurrence rules. It only
uses a single timer at any given time (rather than reevaluating
upcoming jobs every second/minute).
You then can use the database to keep a "state" of the application so on start-up of the application you read all the upcoming jobs that will be expected and load them into node-schedule and let node-schedule do the rest.

The Google Cloud solution for scheduling a single item of future work is Cloud Tasks. Firebase is part of Google Cloud, so this is the most natural product to use. You can use this to avoid polling the database by simply specifying exactly when some Cloud Function should run to do the work you want.
I've written a blog post that demonstrates how to set up a Cloud Task to call a Cloud Functions to delete a document in Firestore with an exact TTL.

Adding a user to PFRelation using Parse Cloud Code

I am using Parse.com with my iPhone app.
I ran into a problem earlier where I was trying to add the currently logged in user to another user's PFRelation key/column called "friendsRelation" which is basically the friends list.
The only problem, is that you are not allowed to save changes to any other users besides the one that is currently logged in.
I then learned, that there is a workaround you can use, using the "master key" with Parse Cloud Code.
I ended up adding the code here to my Parse Cloud Code: https://stackoverflow.com/a/18651564/3344977
This works great and I can successfully test this and add an NSString to a string column/key in the Parse database.
However, I do not know how to modify the Parse Cloud Code to let me add a user to another user's PFRelation column/key.
I have been trying everything for the past 2 hours with the above Parse Cloud Code I linked to and could not get anything to work, and then I realized that my problem is with the actual cloud code, not with how I'm trying to use it in xcode, because like I said I can get it to successfully add an NSString object for testing purposes.
My problem is that I do not know javascript and don't understand the syntax, so I don't know how to change the Cloud Code which is written in javascript.
I need to edit the Parse Cloud Code that I linked to above, which I will also paste below at the end of this question, so that I can add the currently logged in PFUser object to another user's PFRelation key/column.
The code that I would use to do this in objective-c would be:
[friendsRelation addObject:user];
So I am pretty sure it is the same as just adding an object to an array, but like I said I don't know how to modify the Parse Cloud Code because it's in javascript.
Here is the Parse Cloud Code:
Parse.Cloud.define('editUser', function(request, response) {
var userId = request.params.userId,
newColText = request.params.newColText;
var User = Parse.Object.extend('_User'),
user = new User({ objectId: userId });
user.set('new_col', newColText);
Parse.Cloud.useMasterKey();
user.save().then(function(user) {
response.success(user);
}, function(error) {
response.error(error)
});
});
And then here is how I would use it in xcode using objective-c:
[PFCloud callFunction:#"editUser" withParameters:#{
#"userId": #"someuseridhere",
#"newColText": #"new text!"
}];
Now it just needs to be modified for adding the current PFUser to another user's PFRelation column/key, which I am pretty sure is technically just adding an object to an array.
This should be fairly simple for someone familiar with javascript, so I really appreciate the help.
Thank you.

I would recommend that you rethink your data model, and extract the followings out of the user table. When you plan a data model, especially for a NoSQL database, you should think about your queries first and plan your structure around that. This is especially true for mobile applications, as server connections are costly and often introduces latency issues if your app performs lots of connections.
Storing followings in the user class makes it easy to find who a person is following. But how would you solve the task of finding all users who follow YOU? You would have to check all users if you are in their followings relation. That would not be an efficient query, and it does not scale well.
When planning a social application, you should build for scalabilty. I don't know what kind of social app you are building, but imagine if the app went ballistic and became a rapidly growing success. If you didn't build for scalability, it would quickly fall apart, and you stood the chance of losing everything because the app suddenly became sluggish and therefore unusable (people have almost zero tolerance for waiting on mobile apps).
Forget all previous prioities about consistency and normalization, and design for scalability.
For storing followings and followers, use a separate "table" (Parse class) for each of those two. For each user, store an array of all usernames (or their objectId) they follow. Do the same for followers. This means that when YOU choose to follow someone, TWO tables need to be updated: you add the other user's username to the array of who you follow (in the followings table), and you also add YOUR username to the array of the other user's followers table.
Using this method, getting a list of followers and followings is extremely fast.
Have a look at this example implementation of Twitter for the Cassandra NoSQL database:
https://github.com/twissandra/twissandra

Update value in DB every five minutes

I am building a webapp where user have a ranking based on their twitter activity and their activity on my website.
Therefore I'd like to update their rank every five minutes, pulling their latest activity from twitter and update it in my database. I was thinking of using something like this:
var minutes = 5, the_interval = minutes * 60 * 1000;
setInterval(function() {
// my update here
}, the_interval);
However, I have several questions about this code:
where should I save it to make sure it is run?
will it slow my program or is it a problem to pull data out of twitter every five minute? Should I use their streaming API instead?
Note: I am using mongoDB

I'd suggest that you create a scheduled task/chron job/etc. (depends on your host OS) to call a separate Node.JS application that performs the specific tasks you want to do periodically and then it would exit when complete. (Or you could use a ChildProcess potentially as well).
While Node.JS is async, there's no need, given the description you provided, to perform this work within the same application process that is serving a web application. In fact, as it sounds like "busy work", it would be best handled by a distinct process to avoid impacting directly any of your interactive web users.

The placement shouldn't really matter as Node is asynchronous.

How to check failed recurring subscription Stripe

How should I design an on-login middleware that checks if the recurring subscription has failed ? I know that Stripe fires events when things happen, and that the best practice is webhooks. The problem is, I can't use webhooks in the current implementation, so I have to check when the user logs in.

The Right Answer:
As you're already aware, webhooks.
I'm not sure what you're doing that webhooks aren't an option in the current implementation: they're just a POST to a publicly-available URL, the same as any end-user request. If you can implement anything else in Node, you can implement webhook support.
Implementing webhooks is not an all-or-nothing proposition; if you only want to track delinquent payments, you only have to implement processing for one webhook event.
The This Has To Work Right Now, Customer Experience Be Damned Answer:
A retrieved Stripe Customer object contains a delinquent field. This field will be set to true if the latest invoice charge has failed.
N.B. This call may take several seconds—sometimes into the double digits—to complete, during which time your site will appear to have ceased functioning to your users. If you have a large userbase or short login sessions, you may also exceed your Stripe API rate limit.

I actually wrote the Stripe support team an email complaining about this issue (the need to loop through every invoice or customer if you're trying to pull out delinquent entries) and it appears that you can actually do this without webhooks or wasteful loops... it's just that the filtering functionality is undocumented. The current documentation shows that you can only modify queries of customers or invoices by count, created (date), and offset... but if you pass in other parameters the Stripe API will actually try to understand the query, so the cURL request:
https://api.stripe.com/v1/invoices?closed=false&count=100&offset=0
will look for only open invoices.... you can also pass a delinquent=true parameter in when looking for delinquent customers. I've only tested this in PHP, so returning delinquent customers looks like this:
Stripe_Customer::all(array(
"delinquent" => true
));
But I believe this should work in Node.js:
stripe.customers.list(
{delinquent:true},
function(err, customers) {
// asynchronously called
});
The big caveat here is that because this filtering is undocumented it could be changed without notice... but given how obvious the approach is, I'd guess that it's pretty safe.