Realtime database update or create functionality - javascript

I have a user object in firebases realtime database. I am querying realtime database and when successful I am wanting to write some new data to the user object under the users node.
My desired outcome: When a user has not fetched the information before, a new field called 'lastViewed' under the user object is created and if the field has already been created then we update the timeViewed keys value. A user can have multiple objects in the array corresponding to the uuid of the fetched data.
Please see the user object below
This may not need to be an array if using .push()
-N0X8VLHTw3xgvD2vJs- : { // this is the users unique key
name: 'myName',
lastViewed: {
[
{
timeViewed: 1651558791, // this is the field to update if exists
datasUniqueKey: 'N17ZmwIsbqaVSGh93Q0' // if this value exists update timeViewed else we create the entry.
},
{
timeViewed: 1651558952,
datasUniqueKey: 'N17ZmwIsbqaVSad3gad'
},
]
}
}
Please see my attempt below.
const getData = database()
.ref(`data/${uniqueKeyFromData}`)
.on('value', snapshot => {
if (snapshot.exists()) {
database()
.ref(`users/${currentFirebaseUserKey}/lastViewed`) // currentFirebaseUserKey = N0X8VLHTw3xgvD2vJs
.once('value', childSnapshot => {
if (childSnapshot.exists()) {
// update
database()
.ref(
`users/${currentFirebaseUserKey}/lastViewed`,
)
.update({
timeViewed: new Date(), // new data will not give us the corresponding date format in the user object above but don't worry about that
fetchedDatasUniqueKey: uniqueKeyFromData,
});
} else {
// create
database()
.ref(
`users/${currentFirebaseUserKey}/lastViewed`,
)
// Push creates a unique key which might not be required so maybe set?
.push({
timeViewed: new Date(),
fetchedDatasUniqueKey: uniqueKeyFromData,
});
}
});
}
});
Where I think I am going wrong
Above I am not creating an array, if I use push I would get a unique key generated from firebase but then would have to use that key when updating, something like
`users/${currentFirebaseUserKey}/lastViewed/${lastViewedUniqueKey}`
So the user object would look like so
-N0X8VLHTw3xgvD2vJs- : { // this is the users unique key
name: 'myName',
lastViewed: {
-N17i2X2-rKYXywbJGmQ: { // this is lastViewedUniqueKey
timeViewed: 1651558791,
datasUniqueKey: 'N17ZmwIsbqaVSGh93Q0'
},
}
}
then check for snapshot.key in the if?, any help would be appreciated.

Since you don't want a list of data, but a single set of properties for ``, you should just call set instead of push:
database()
.ref(`users/${currentFirebaseUserKey}/lastViewed`)
.set({ // 👈
timeViewed: new Date(),
fetchedDatasUniqueKey: uniqueKeyFromData,
});
I also don't think you need the two different cases here for create vs update, as both seem to do the exact same thing. If you do need both cases though, consider using a transaction.

Related

how to add objects to array in firestore?

I have the below code which at first run creates a new collection with a document ID that is equal to my UID. This newly created document has an array named 'array' which contains the cocktailInformation object. So far all works fine.
const saveData = (uid) => {
db
.collection('users')
.doc(uid)
.set({
array: [ cocktailInformation ]
})
.then(function() {
console.log('Document successfully written!');
})
.catch(function(error) {
console.error('Error writing document: ', error);
});
};
the issue arises when i want to add more objects to this array in this document. I checked firestore docs on how to do this and it shows the below
var washingtonRef = db.collection("cities").doc("DC");
// Atomically add a new region to the "regions" array field.
washingtonRef.update({
regions: firebase.firestore.FieldValue.arrayUnion("greater_virginia")
});
// Atomically remove a region from the "regions" array field.
washingtonRef.update({
regions: firebase.firestore.FieldValue.arrayRemove("east_coast")
});
but i don't know how to integrate this as the current code only updates the current object with the one i send off to firestore. Can anyone give me some tips? BTW this is a react app
You can update the document by doing the following:
db.collection('users').doc(uid).update({
array: firebase.firestore.FieldValue.arrayUnion("value")
});

Firebase adding item to array [duplicate]

I'm currently trying Firestore, and I'm stuck at something very simple: "updating an array (aka a subdocument)".
My DB structure is super simple. For example:
proprietary: "John Doe",
sharedWith:
[
{who: "first#test.com", when:timestamp},
{who: "another#test.com", when:timestamp},
],
I'm trying (without success) to push new records into shareWith array of objects.
I've tried:
// With SET
firebase.firestore()
.collection('proprietary')
.doc(docID)
.set(
{ sharedWith: [{ who: "third#test.com", when: new Date() }] },
{ merge: true }
)
// With UPDATE
firebase.firestore()
.collection('proprietary')
.doc(docID)
.update({ sharedWith: [{ who: "third#test.com", when: new Date() }] })
None works. These queries overwrite my array.
The answer might be simple, but I could'nt find it...
Firestore now has two functions that allow you to update an array without re-writing the entire thing.
Link: https://firebase.google.com/docs/firestore/manage-data/add-data, specifically https://firebase.google.com/docs/firestore/manage-data/add-data#update_elements_in_an_array
Update elements in an array
If your document contains an array field, you can use arrayUnion() and
arrayRemove() to add and remove elements. arrayUnion() adds elements
to an array but only elements not already present. arrayRemove()
removes all instances of each given element.
Edit 08/13/2018: There is now support for native array operations in Cloud Firestore. See Doug's answer below.
There is currently no way to update a single array element (or add/remove a single element) in Cloud Firestore.
This code here:
firebase.firestore()
.collection('proprietary')
.doc(docID)
.set(
{ sharedWith: [{ who: "third#test.com", when: new Date() }] },
{ merge: true }
)
This says to set the document at proprietary/docID such that sharedWith = [{ who: "third#test.com", when: new Date() } but to not affect any existing document properties. It's very similar to the update() call you provided however the set() call with create the document if it does not exist while the update() call will fail.
So you have two options to achieve what you want.
Option 1 - Set the whole array
Call set() with the entire contents of the array, which will require reading the current data from the DB first. If you're concerned about concurrent updates you can do all of this in a transaction.
Option 2 - Use a subcollection
You could make sharedWith a subcollection of the main document. Then
adding a single item would look like this:
firebase.firestore()
.collection('proprietary')
.doc(docID)
.collection('sharedWith')
.add({ who: "third#test.com", when: new Date() })
Of course this comes with new limitations. You would not be able to query
documents based on who they are shared with, nor would you be able to
get the doc and all of the sharedWith data in a single operation.
Here is the latest example from the Firestore documentation:
firebase.firestore.FieldValue.ArrayUnion
var washingtonRef = db.collection("cities").doc("DC");
// Atomically add a new region to the "regions" array field.
washingtonRef.update({
regions: firebase.firestore.FieldValue.arrayUnion("greater_virginia")
});
// Atomically remove a region from the "regions" array field.
washingtonRef.update({
regions: firebase.firestore.FieldValue.arrayRemove("east_coast")
});
You can use a transaction (https://firebase.google.com/docs/firestore/manage-data/transactions) to get the array, push onto it and then update the document:
const booking = { some: "data" };
const userRef = this.db.collection("users").doc(userId);
this.db.runTransaction(transaction => {
// This code may get re-run multiple times if there are conflicts.
return transaction.get(userRef).then(doc => {
if (!doc.data().bookings) {
transaction.set({
bookings: [booking]
});
} else {
const bookings = doc.data().bookings;
bookings.push(booking);
transaction.update(userRef, { bookings: bookings });
}
});
}).then(function () {
console.log("Transaction successfully committed!");
}).catch(function (error) {
console.log("Transaction failed: ", error);
});
Sorry Late to party but Firestore solved it way back in aug 2018 so If you still looking for that here it is all issues solved with regards to arrays.
https://firebase.googleblog.com/2018/08/better-arrays-in-cloud-firestore.htmlOfficial blog post
array-contains, arrayRemove, arrayUnion for checking, removing and updating arrays. Hope it helps.
To build on Sam Stern's answer, there is also a 3rd option which made things easier for me and that is using what Google call a Map, which is essentially a dictionary.
I think a dictionary is far better for the use case you're describing. I usually use arrays for stuff that isn't really updated too much, so they are more or less static. But for stuff that gets written a lot, specifically values that need to be updated for fields that are linked to something else in the database, dictionaries prove to be much easier to maintain and work with.
So for your specific case, the DB structure would look like this:
proprietary: "John Doe"
sharedWith:{
whoEmail1: {when: timestamp},
whoEmail2: {when: timestamp}
}
This will allow you to do the following:
var whoEmail = 'first#test.com';
var sharedObject = {};
sharedObject['sharedWith.' + whoEmail + '.when'] = new Date();
sharedObject['merge'] = true;
firebase.firestore()
.collection('proprietary')
.doc(docID)
.update(sharedObject);
The reason for defining the object as a variable is that using 'sharedWith.' + whoEmail + '.when' directly in the set method will result in an error, at least when using it in a Node.js cloud function.
#Edit (add explanation :) )
say you have an array you want to update your existing firestore document field with. You can use set(yourData, {merge: true} ) passing setOptions(second param in set function) with {merge: true} is must in order to merge the changes instead of overwriting. here is what the official documentation says about it
An options object that configures the behavior of set() calls in DocumentReference, WriteBatch, and Transaction. These calls can be configured to perform granular merges instead of overwriting the target documents in their entirety by providing a SetOptions with merge: true.
you can use this
const yourNewArray = [{who: "first#test.com", when:timestamp}
{who: "another#test.com", when:timestamp}]
collectionRef.doc(docId).set(
{
proprietary: "jhon",
sharedWith: firebase.firestore.FieldValue.arrayUnion(...yourNewArray),
},
{ merge: true },
);
hope this helps :)
addToCart(docId: string, prodId: string): Promise<void> {
return this.baseAngularFirestore.collection('carts').doc(docId).update({
products:
firestore.FieldValue.arrayUnion({
productId: prodId,
qty: 1
}),
});
}
i know this is really old, but to help people newbies with the issue
firebase V9 provides a solution using the arrayUnion and arrayRemove
await updateDoc(documentRef, {
proprietary: arrayUnion( { sharedWith: [{ who: "third#test.com", when: new Date() }] }
});
check this out for more explanation
Other than the answers mentioned above. This will do it.
Using Angular 5 and AngularFire2. or use firebase.firestore() instead of this.afs
// say you have have the following object and
// database structure as you mentioned in your post
data = { who: "third#test.com", when: new Date() };
...othercode
addSharedWith(data) {
const postDocRef = this.afs.collection('posts').doc('docID');
postDocRef.subscribe( post => {
// Grab the existing sharedWith Array
// If post.sharedWith doesn`t exsit initiated with empty array
const foo = { 'sharedWith' : post.sharedWith || []};
// Grab the existing sharedWith Array
foo['sharedWith'].push(data);
// pass updated to fireStore
postsDocRef.update(foo);
// using .set() will overwrite everything
// .update will only update existing values,
// so we initiated sharedWith with empty array
});
}
We can use arrayUnion({}) method to achive this.
Try this:
collectionRef.doc(ID).update({
sharedWith: admin.firestore.FieldValue.arrayUnion({
who: "first#test.com",
when: new Date()
})
});
Documentation can find here: https://firebase.google.com/docs/firestore/manage-data/add-data#update_elements_in_an_array
Consider John Doe a document rather than a collection
Give it a collection of things and thingsSharedWithOthers
Then you can map and query John Doe's shared things in that parallel thingsSharedWithOthers collection.
proprietary: "John Doe"(a document)
things(collection of John's things documents)
thingsSharedWithOthers(collection of John's things being shared with others):
[thingId]:
{who: "first#test.com", when:timestamp}
{who: "another#test.com", when:timestamp}
then set thingsSharedWithOthers
firebase.firestore()
.collection('thingsSharedWithOthers')
.set(
{ [thingId]:{ who: "third#test.com", when: new Date() } },
{ merge: true }
)
If You want to Update an array in a firebase document.
You can do this.
var documentRef = db.collection("Your collection name").doc("Your doc name")
documentRef.update({
yourArrayName: firebase.firestore.FieldValue.arrayUnion("The Value you want to enter")});
Although firebase.firestore.FieldValue.arrayUnion() provides the solution for array update in firestore, at the same time it is required to use {merge:true}. If you do not use {merge:true} it will delete all other fields in the document while updating with the new value. Here is the working code for updating array without loosing data in the reference document with .set() method:
const docRef = firebase.firestore().collection("your_collection_name").doc("your_doc_id");
docRef.set({yourArrayField: firebase.firestore.FieldValue.arrayUnion("value_to_add")}, {merge:true});
If anybody is looking for Java firestore sdk solution to add items in array field:
List<String> list = java.util.Arrays.asList("A", "B");
Object[] fieldsToUpdate = list.toArray();
DocumentReference docRef = getCollection().document("docId");
docRef.update(fieldName, FieldValue.arrayUnion(fieldsToUpdate));
To delete items from array user: FieldValue.arrayRemove()
If the document contains a nested object in the form of an array, .dot notation can be used to reference and update nested fields.
Node.js example:
const users = {
name: 'Tom',
surname: 'Smith',
favorites: {
sport: 'tennis',
color: 'red',
subject: 'math'
}
};
const update = await db.collection('users').doc('Tom').update({
'favorites.sport': 'snowboard'
});
or Android sdk example:
db.collection("users").document("Tom")
.update(
'favorites.sport': 'snowboard'
);
There is a simple hack in firestore:
use path with "." as property name:
propertyname.arraysubname.${id}:
db.collection("collection")
.doc("docId")
.update({arrayOfObj: fieldValue.arrayUnion({...item})})

document wont save using save() method with mongoose

I have this schema:
var UserSchema = mongoose.Schema({
analytic: {
type: Object,
default: {
today:[],
weekly:[],
monthly:[],
yearly:[],
allTime:[]
}
}
});
let User = mongoose.model("bloger", UserSchema);
module.exports = {User};
and I am trying to save some data into one of the arrays like so:
User.findOne({username:username}, (e, user) => {
if (e) {
res.send('error fetching post')
}
else if (!user) {
res.send('no user found')
}
else if (user) {
user.analytic.today.push(req.body.visitor) // push the data object to the array
user.save((e, doc) => {
if (e) {
res.send(e)
}
if (doc) {
console.log('user saved')
res.send(doc)
}
})
}
})
})
I am getting the doc object on save() and not the e so I though it should have save it but it wasn't.
I have had a similar issue before this is because I am not defining a new Model I am just passing a JSON object.
Instead of saving the object you need to create a new model and save that.
Try creating a new model passing the save into it like below;
var newUser = new User(user);
newUser.save((e, doc) {
if (e) {
res.send(e)
}
if (doc) {
console.log('user saved')
res.send(doc)
}
});
Making sure you require the User Model inside the script.
Performing deep modifications in objects not in your schema makes Mongoose oblivious to those changes, preventing it from knowing what to save (and from making efficient atomic updates). The end result is that, when calling .save, Mongoose thinks there's nothing modified and therefore does nothing.
In your particular scenario, you have two options:
1. Add your analytics sub-arrays to your schema
This is the best option and allows for finer control of everything:
const UserSchema mongoose.Schema({
analytic: {
today: [{}],
weekly: [{}],
monthly: [{}],
yearly: [{}],
allTime: [{}],
}
});
With this, those arrays are now known to Mongoose and everything should work correctly.
Note that you don't need defaults in this case, as Mongoose is smart enough to create the arrays as needed.
2. Manually mark modified object as modified
If for any reason you don't want or can't modify the schema, you can manually mark the analytic object as modifies so Mongoose knows of it:
user.analytic.today.push(req.body.visitor) // push the data object to the array
user.markModified('analytic'); // mark field as modified
user.save(...);
This signals Mongoose that analytic or any of its children have changed and triggers an update when calling .save. Note however that Mongoose views this as a full change in the object, while with option 1 it can use $push instead.

Mongo update removing other keys in document

I am trying mongo update where one document key from a different collection is inserted into another collection.
CODE
// update user document with remove of otp and new state set.
updateOne = await db.collection(_collection).updateOne(
// search basis.
__docUpdateSearchBasis,
// updates.
__docUpdateBasis
)
RESULT
You need to make query like this:
updateOne = await db.collection(_collection).findOneAndUpdate(
//Condition
{
_id: req.user.id
},
//Update what you want
{
$set: {
key: value
}
});

Migrate simple List Array key to another key with an extra attribute in MongoDB

Sorry if I'm not getting the terminology right. Here's what I have currently my MongoDB user docs db.users:
"liked" : [
"EBMKgrD4DjZxkxvfY",
"WJzAEF5EKB5aaHWC7",
"beNdpXhYLnKygD3yd",
"RHP3hngma9bhXJQ2g",
"vN7uZ2d6FSfzYJLmm",
"NaqAsFmMmnhqNbqbG",
"EqWEY3qkeJYQscuZJ",
"6wsrFW5pFdnQfoWMs",
"W4NmGXyha8kpnJ2bD",
"8x5NWZiwGq5NWDRZX",
"Qu8CSXveQxdYbyoTa",
"yLLccTvcnZ3D3phAs",
"Kk36iXMHwxXNmgufj",
"dRzdeFAK28aKg3gEX",
"27etCj4zbrKhFWzGS",
"Hk2YpqgwRM4QCgsLv",
"BJwYWumwkc8XhMMYn",
"5CeN95hYZNK5uzR9o"
],
And I am trying to migrate them to a new key that also captures the time that a user liked the post
"liked_time" : [
{
"postId" : "5CeN95hYZNK5uzR9o",
"likedAt" : ISODate("2015-09-23T08:05:51.957Z")
}
],
I am wondering if it might be possible to simply do this within the MongoDB Shell with a command that iterates over each user doc and then iterates over the liked array and then updates and $push the new postId and time.
Or would it be better to do this in JavaScript. I am using Meteor.
I almost got it working for individual users. But want to know if I could do all users at once.
var user = Meteor.users.findOne({username:"atestuser"});
var userLiked = user.liked;
userLiked.forEach(function(entry) {
Meteor.users.update({ username: "atestuser" },
{ $push: { liked_times: { postId: entry, likedAt: new Date() }}});
console.log(entry);
});
Still a bit of a newbie to MongoDB obviously......
Here is something i made real quick you should run this on the server side just put it into a file e.g. "migrate.js" in root meteor and run the meteor app
if (Meteor.isServer) {
Meteor.startup(function () {
var users = Meteor.users.find().fetch();
users.forEach(function (doc) {
liked.forEach(function (postId) {
Meteor.users.update(doc._id, { $push: { liked_times: { postId: postId, likedAt: new Date() } } });
});
});
console.log('finished migrating');
});
}
p.s I didn't test it
If this is a one time migration i would do something like this in a one time js script.
Get all users
Iterate over each user
Get all likes
Iterate over them, get likedAt
var liked_times = _.collect(likes, function (likeId) {
return {
'postId' : likeId,
'likedAt': // get post liked time from like id.
}
});
Insert the above in the collection of choice.
Note:
The above example makes use of lodash
I would rather just save likedAt as a timestamp.

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