Does Firebase send ALL the data under a given path? - javascript

I'm a little confused as to how much data is automatically fetched by Firebase and I'm having a hard time modeling data.
As I understand it, an authenticated user's ID is compared to the path; if the key is missing, the path is inaccessible. In addition, once a path is called, all of the data within it is accessed.
For instance, fetching /cart/<$uid>/<item> would also include $uid1, $uid, $uid3 ... $uidN, etc. So if I were to nest all of the data under /<$uid>, like:
/<$uid>/cart
/<$uid>/orders
/<$uid>/transactions
Does this mean that fetching /<$uid>/cart also returns all those other keys? What if I only call <$uid>?
If the structure is instead by cart/ or orders/ first, does this mean all the orders for all the users are fetched?
In other words, when a user logs in, I'd like to retrieve the contents of (using one of those "schemas") the cart:
// Fires onAuthStateChanged()
firebaseListener(function authStateChange(loggedIn, user) {
if (store) {
if (user) {
store.dispatch('getShoppingCart', { uid: user.uid, currentCart: store.getters.cartItemList });
store.dispatch('setUser', user);
}
}
})
getShoppingCart then runs something similar to:
let ref = db.ref('/cart/' + store.state.uid + '/')
ref.on('value', (snapshot) => {
store.cart.concat(snapshot)
})

When a user logs in, you are retrieving the information of that user, so when you use uid, you are retrieving the id of that login user.
When you use this ref('/cart/' + store.state.uid + '/') it will go to cart node first and then the uid of that user and not all userids who are under carts.
You can also use once('value').then(function(snapshot) { which will only read the data once and not trigger again.

Related

Importing User Data from filtered Array (VUE3 + Quasar + Firebase)

I am importing the data from the currently signed in user in order to manage the entire user profile page and all the associated actions.
On one hand I have the auth.currentUser and on the other I have the USERS collection in the db which stores all the additional data related to that particular user.
Now, my question concerns optimization. What would be the ideal way to get this user's data? Currently I am getting the entire users collection and filtering to get the one that matched the uid from the route params, yet I was told that loading the entire users collection and filtering the one I want to display was less than ideal, that I should rather create a function to get a specific user by a property such as name or id. This is what confuses me, is that not essentially what I am doing by filtering the users collection? How else would it be best to get that user's info? By creating this function in the Store and not in the component itself?
Currently it's looking like this:
UserPage.vue
const storeUsers = useUserStore();
const users = storeUsers.users;
const route = useRoute();
const id = route.params.id;
const userData = computed(() => {
return users.find((u) => u.uid == id);
});
Any way to optimize this would be appreciated.
*Adding a screenshot of the Firestore console (data model):
Your code is loading every document from the users collection into your application code, and then choosing there which single document you are actually interested in. Since you pay for every document read from the database, and you (and your users) pay for all bandwidth that is used, this is wasteful - especially as you start adding more users to the collection.
Instead you should use a query to read only the document(s) you are interested in from the database into your application code. Read the documentation for examples for all supported SDK versions.
finally solved it using a query as suggested. I am triggering the getUserInfo action whenever a user signs in and then assigning it to a pinia state called currentUserData:
AUTH STORE
async getUsers() {
onSnapshot(userCollectionRef, (querySnapshot) => {
let users = [];
querySnapshot.forEach((doc) => {
let user = {
did: doc.id,
...doc.data(),
};
this.users.push(user);
});
});
},
getUserInfo(userCredential) {
const q = query(
userCollectionRef,
where("uid", "==", userCredential.user.uid)
);
onSnapshot(q, (snapshot) => {
let currentUserData = [];
snapshot.docs.forEach((doc) => {
currentUserData.push({ ...doc.data(), id: doc.id });
});
this.currentUserData = currentUserData;
});
}

How to fetch a single data value out of firebase database with reactjs

Im working on a project trying to fetch a name of the current user that is logged in.
When we create a user its getting added in the database with a unique id as row name.
Here you can see all the users that are registered but i only want the one that is logged in so i can pick the first and last name to say "Hello (bla) (bla)"
The code i have now it this :
import React from "react"
import { auth, database } from '../../handlers/Firebase'
export default function Dashboard() {
const user = auth.currentUser
const refUserInformation = database.ref('UserInformation/')
refUserInformation.on('value', function(data){
console.log(data.val())
})
return (
<div className="page-dashboard">
<div className="maxtext">
<p>userid: {user.uid}</p>
<p>Naam: </p>
</div>
</div>
)
}
Can just someone help me out with fetching the logged in user (so not a loop)
In summary, the problem is that I currently get all users back in my console log, but I only need the one that is logged in and on the appropriate dashboard. I would like to post this name (not with a loop but a single request)
To get just the user with a given user_id value, you will have to use a query:
const refUserInformation = database.ref('UserInformation/')
const currentUserQuery = refUserInformation.orderByChild('user_id').equalTo(user.uid);
currentUserQuery.on('value', function(snapshot){
snapshot.forEach((data) => {
console.log(data.val())
});
})
In general, I'd recommend storing user information with the UID as the key. That way:
Each UID can by definition occur only once in the database, since keys are unique under a parent node.
Looking up the user info by their UID becomes simpler, since you won't need a query.
To store the user under their UID use refUserInformation.child(user.uid).set(...) instead of refUserInformation.push(..).

How to notify the front end that it needs to refresh after setting a custom claim with Firebase cloud functions onCreate listener

I'm trying to initialize a user upon registration with a isUSer role using custom claims and the onCreate listener. I've got it to set the correct custom claim but the front end is aware of it only after a full page refresh.
I've been following this article, https://firebase.google.com/docs/auth/admin/custom-claims?authuser=0#logic, to notify the front end that it needs to refresh the token in order to get the latest changes on the custom claims object, but to be honest I don't quite fully understand what's going on in the article.
Would someone be able to help me successfully do this with the firestore database ?
This is my current cloud function:
exports.initializeUserRole = functions.auth.user().onCreate(user => {
return admin.auth().setCustomUserClaims(user.uid, {
isUser: true
}).then(() => {
return null;
});
});
I've tried adapting the real-time database example provided in the article above to the firestore database but I've been unsuccessful.
exports.initializeUserRole = functions.auth.user().onCreate(user => {
return admin.auth().setCustomUserClaims(user.uid, {
isUser: true
}).then(() => {
// get the user with the updated claims
return admin.auth().getUser(user.uid);
}).then(user => {
user.metadata.set({
refreshTime: new Date().getTime()
});
return null;
})
});
I thought I could simply set refreshTime on the user metadata but there's no such property on the metadata object.
In the linked article, does the metadataRef example provided not actually live on the user object but instead somewhere else in the database ?
const metadataRef = admin.database().ref("metadata/" + user.uid);
If anyone could at least point me in the right direction on how to adapt the real-time database example in the article to work with the firestore database that would be of immense help.
If my description doesn't make sense or is missing vital information let me know and I'll amend it.
Thanks.
The example is using data stored in the Realtime Database at a path of the form metadata/[userID]/refreshTime.
To do the same thing in Firestore you will need to create a Collection named metadata and add a Document for each user. The Document ID will be the value of user.uid. Those documents will need a timestamp field named refreshTime.
After that, all you need to do is update that field on the corresponding Document after the custom claim has been set for the user. On the client side, you will subscribe to changes for the user's metadata Document and update in response to that.
Here is an example of how I did it in one of my projects. My equivalent of the metadata collection is named userTokens. I use a transaction to prevent partial database changes in the case that any of the steps fail.
Note: My function uses some modern JavaScript syntax that is being transpiled with Babel before uploading.
exports.initializeUserData = functions.auth.user().onCreate(async user => {
await firestore.collection('userTokens').doc(user.uid).set({ accountStatus: 'pending' })
const tokenRef = firestore.collection('userTokens').doc(user.uid)
const userRef = firestore.collection('users').doc(user.uid)
const permissionsRef = firestore.collection('userPermissions').doc(user.email)
await firestore.runTransaction(async transaction => {
const permissionsDoc = await transaction.get(permissionsRef)
const permissions = permissionsDoc.data();
const customClaims = {
admin: permissions ? permissions.admin : false,
hasAccess: permissions ? permissions.hasAccess : false,
};
transaction.set(userRef, { name: user.displayName, email: user.email, getEmails: customClaims.hasAccess })
await admin.auth().setCustomUserClaims(user.uid, customClaims)
transaction.update(tokenRef, { accountStatus: 'ready', refreshTime: admin.firestore.FieldValue.serverTimestamp() })
});
})

How to obtain a record of a node, according to the value of a property, firebase?

I currently have the following node:
Basically what I want is to search the registry by the uid parameter. What I can not understand is that they tell me that I should not do it by means of a query, so what would be the other way? I have tried with the following:
firebase
.database()
.ref('nuevosUsuario')
.child(user.uid)
.once('value')
.then(snapshot =>
console.log(snapshot.val())
);
pero me imprime en consola null
Thank you in advance, I'm new to firebase.
You JSON structure stores user information, where it stores the information for each user under a so-called push ID (a key generated by calling push() or childByAutoId()). You're trying to query this structure to find the user based on their UID, which is stored in a property for each user. The only way to do this is by using a database query, like:
firebase.database()
.ref('nuevosUsuario')
.orderByChild("uid")
.child(user.uid)
.once('value')
.then(snapshot => {
snapshot.forEach(userSnapshot => {
console.log(snapshot.val())
});
});
You need to perform a loop here, since there may be multiple nodes that have the correct value for their UID property.
If there can logically be only one node for each user under nuevosUsuario, it is better to store the user information under the user's UID as a key, instead of using a push ID.
So you'd get a structure like:
"nuevosUsuario": {
"SYFW1u808weaGEf3fW...": {
"appellido": "PRUEBA",
"correo": "..."
...
}
}
This has a few advantages:
There can only be one child node for each user, since keys are by definition unique in a collection.
You can now get the user given their UID without a query, which is both faster and simpler in code. As in: the code in your question would work for this structure.

firebase simple - data structure questions

I have been reading a little about how to structure your firebase database and i understand that you need to split your data into pieces so you don't forced the client to download all of the 'users' data.
So in this example you will get all the users data when you write
ref.('users').once('value', function(snap)...
/users/uid
/users/uid/email
/users/uid/messages
/users/uid/widgets
but what if you specifically write the path to the location instead like
ref.('users/uid/email').once('value', function(snap)...
Will you still get all the users data or only the data in email ?
In firebase, you set the ref to be the reference for your database (the whole database) and then you got methods to iterate through each piece of data of your database object, hence, a good practice is to set all your database as the ref and then work from there to go through what you want to go.
// will select the whole db
const firebaseRef = firebase.database().ref();
// will select the whole app object of your db
const firebaseRef = firebase.database().ref().child('app');
// will select the whole users object of your db
const firebaseRef = firebase.database().ref().child('app/users');
So, it is a good practice to set a variable like firebaseRef to be your whole firebase db and then iterate from there.
Now, if you write:
firebaseRef.child(`users/${uid}/email`).once('value').then(snapshot => {
console.log('User email: ', snapshot.val());
}, e => {
console.log('Unable to fetch value');
});
Yes, you will get what you're asking, but you need to use the child method to get to the objects of your firebase ref.

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