so I've been researching a lot and apparently no method is working to add timestamp to my firebase data and then sort the data accordingly. I tried the traditional "timestamp": [".sv":"timestamp"] method and that only adds a value of .sv: Timestamp in firebase. Then I tried self.createdAt = Date(timeIntervalSince1970: timestamp/1000) and added that to where I add the item to firebase but that didn't help either.So doesn't anyone know what's the most straightforward method to add timestamp to firebase via swift? Would appreciate any input! Thanks.
EDIT:
Here's now I define the item being added to firebase:
struct Note: Identifiable, Codable {
var id: String
var content: String
var createdAt: String
}
Here's how I define fetching that item from firebase:
func fetchNotes () {
notes.removeAll()
let uid = Auth.auth().currentUser!.uid
let db = Firestore.firestore()
let ref = db.collection("userslist").document(uid).collection("actualnotes")
ref.order(by: "createdAt", descending: true).addSnapshotListener{ (querySnapshot, error) in
let documents = querySnapshot!.documents
if querySnapshot!.isEmpty {
let ref = db.collection("userslist").document(uid).collection("actualnotes")
ref.document().setData(["content": "Welcome", "createdAt": FieldValue.serverTimestamp() ])
}
else {
self.notes = documents.map { (queryDocumentSnapshot) -> Note in
let data = queryDocumentSnapshot.data()
let id = queryDocumentSnapshot.documentID
let content = data["content"] as! String ?? ""
let createdAt = data["createdAt"] as? String ?? "" // this is where
// it breaks with the error (Thread 1: signal SIGABRT)
let note = Note(id:id, content:content, createdAt: createdAt)
return (note)
}
}
}
}
And here's where I want the timestamp to appear in another view:
List{ ForEach(dataManager.notes) { note in
NavigationLink(destination: NoteView(newNote: note.content, idd: note.id ))
{
HStack {
Text(note.createdAt)
}})}}
The [".sv":"timestamp"] applies to the Realtime Database only, while you are using Cloud Firestore. While both databases are part of Firebase, they are completely separate and the API of one does not apply to the other.
For Firestore follow its documentation on writing a server-side timestamp, which says it should be:
db.collection("objects").document("some-id").updateData([
"lastUpdated": FieldValue.serverTimestamp(),
])
If that doesn't work, edit your question to show the exact error you get.
Related
Thanks in advance for the help. I'm teaching myself Swift and trying to figure out how to retrieve the following data from Firebase. Here's my Firebase Data Model...
Groups (Collection)
-> GroupName (String)
-> Owner (References to someone in the Players collection)
Players (Collection)
-> PlayerFirstName
-> PlayerLastName
The Swift I've written to retrieve this data is in a ViewModel. getAllGroups is called from onAppear in the View and looks like this...
class Group: Identifiable, ObservableObject {
var id: String = UUID().uuidString
var name: String?
var owner: Player?
}
class GroupViewModel: ObservableObject {
#Published var groups = [Group]()
private var db = Firestore.firestore()
func getAllGroups() {
db.collection("groups").addSnapshotListener { (querySnapshot, error) in
guard let documents = querySnapshot?.documents else {
print("No groups")
return
}
self.groups = documents.map { (queryDocumentSnapshot) -> Group in
var group = Group()
let data = queryDocumentSnapshot.data()
group.name = data["name"] as? String ?? ""
//
// LIKE --- SHOULD THIS CALL TO GETPLAYER use AWAIT, FOR EXAMPLE?
// WE'RE EXECUTING THE CLOSURE FOR THE FIRST CALL AND ABOUT TO MAKE A SECOND
//
group.owner = self.getPlayer(playerRef: data["owner"] as! DocumentReference)
return group
}
}
}
func getPlayer(playerRef: DocumentReference) -> Player {
var player = Player()
playerRef.getDocument { (document, error) in
guard error == nil else {
print ("error", error ?? "")
return
}
if let document = document, document.exists {
let data = document.data()
if let data = data {
player.firstName = data["firstname"] as? String
player.lastName = data["lastname"] as? String
}
}
}
return player
}
}
The sorta obvious problem here is the closure for retrieving the parent Group executes and then goes and tries to retrieve the Owner. But by the time the closure inside getPlayer completes... the Group has already been established.
Groups will have...
group[0]
-> GroupName = "Cool Name Here"
-> Owner = nil
group[0]
-> GroupName = "Different Cool Name"
-> Owner = nil
even though each Group definitely has an Owner.
I get there's some stuff here about asynchronous calls in Swift and how best to handle that... I'm just not sure what the proper pattern is. Thanks again for the help and advice!
-j
To restate the question:
How do you nest Firestore functions
There are 100 ways to do it and, a lot of it depends on the use case. Some people like DispatchGroups, others like escaping completion handlers but in a nutshell, they pretty much do the "same thing" as the following code, written out "long hand" for readability
func populateGroupArray() {
db.collection("groups").addSnapshotListener { (querySnapshot, error) in
guard let docs = querySnapshot?.documents else { return }
for doc in docs {
let groupName = doc.get("name") as! String
let ownerId = doc.get("owner_id") as! String
self.addToArray(groupName: groupName, andOwnerId: ownerId)
}
}
}
func addToArray(groupName: String, andOwnerId: String) {
db.collection("owners").document(andOwnerId).getDocument(completion: { snapshot, error in
let name = snapshot?.get("owner_name") as! String
let group = Group(groupName: groupName, ownerName: name)
self.groups.append(group)
})
}
In summary; calling populateGroupArray reads in all of the documents from the groups collection from Firestore (adding a listener too). We then iterate over the returned documents to get each group name and the owner id of the group.
Within that iteration, the group name and ownerId are passed to another function that reads in that specific owner via it's ownerId and retrieves the name
Finally, a Group object is instantiated with groupName and owner name being populated. That group is then added to a class var groups array.
Now, if you ask a Firebaser about this method, they will generally recommend not reading large amounts of Firebase data 'in a tight loop'. That being said, this will work very well for many use cases.
In the case you've got a HUGE dataset, you may want to consider denormalizing your data by including the owner name in the group. But again, that would be a rare situation.
I've spent days researching this including various answers like: Firebase Firestore: Append/Remove items from document array and my previous question at: Removing an array item from Firestore
but can't work out how to actually get this working. Turns out the issue is when there is a date property in the object as shown below:
I have two structs:
struct TestList : Codable {
var title : String
var color: String
var number: Int
var date: Date
var asDict: [String: Any] {
return ["title" : self.title,
"color" : self.color,
"number" : self.number,
"date" : self.date]
}
}
struct TestGroup: Codable {
var items: [TestList]
}
I am able to add data using FieldValue.arrayUnion:
#objc func addAdditionalArray() {
let testList = TestList(title: "Testing", color: "blue", number: Int.random(in: 1..<999), date: Date())
let docRef = FirestoreReferenceManager.simTest.document("def")
docRef.updateData([
"items" : FieldValue.arrayUnion([["title":testList.title,
"color":testList.color,
"number":testList.number,
"date": testList.date]])
])
}
The above works as reflected in the Firestore dashboard:
But if I try and remove one of the items in the array, it just doesn't work.
#objc func deleteArray() {
let docRef = FirestoreReferenceManager.simTest.document("def")
docRef.getDocument { (document, error) in
do {
let retrievedTestGroup = try document?.data(as: TestGroup.self)
let retrievedTestItem = retrievedTestGroup?.items[1]
guard let itemToRemove = retrievedTestItem else { return }
docRef.updateData([
"items" : FieldValue.arrayRemove([itemToRemove.asDict])
]) { error in
if let error = error {
print("error: \(error)")
} else {
print("successfully deleted")
}
}
} catch {
}
}
}
I have printed the itemToRemove to the log to check that it is correct and it is. But it just doesn't remove it from Firestore. There is no error returned, yet the "successfully deleted" is logged.
I've tried different variations and this code works as long as I don't have a date property in the struct/object. The moment I add a date field, it breaks and stops working. Any ideas on what I'm doing wrong here?
Please note: I've tried passing in the field values as above in FieldValue.arrayUnion as well as the object as per FieldValue.arrayRemove and the same issue persists regardless of which method I use.
The problem is, as you noted, the Date field. And it's a problem because Firestore does not preserve the native Date object when it's stored in the database--they are converted into date objects native to Firestore. And the go-between these two data types is a token system. For example, when you write a date to Firestore from a Swift client, you actually send the database a token which is then redeemed by the server when it arrives which then creates the Firestore date object in the database. Conversely, when you read a date from Firestore on a Swift client, you actually receive a token which is then redeemed by the client which you then can convert into a Swift Date object. Therefore, the definition of "now" is not the same on the client as it is on the server, there is a discrepancy.
That said, in order to remove a specific item from a Firestore array, you must recreate that exact item to give to FieldValue.arrayRemove(), which as you can now imagine is tricky with dates. Unlike Swift, you cannot remove items from Firestore arrays by index. Therefore, if you want to keep your data architecture as is (because there is a workaround I will explain below), the safest way is to get the item itself from the server and pass that into FieldValue.arrayRemove(). You can do this with a regular read and then execute the remove in the completion handler or you can perform it atomically (safer) in a transaction.
let db = Firestore.firestore()
db.runTransaction { (trans, errorPointer) -> Any? in
let doc: DocumentSnapshot
let docRef = db.document("test/def")
// get the document
do {
try doc = trans.getDocument(docRef)
} catch let error as NSError {
errorPointer?.pointee = error
return nil
}
// get the items from the document
if let items = doc.get("items") as? [[String: Any]] {
// find the element to delete
if let toDelete = items.first(where: { (element) -> Bool in
// the predicate for finding the element
if let number = element["number"] as? Int,
number == 385 {
return true
} else {
return false
}
}) {
// element found, remove it
docRef.updateData([
"items": FieldValue.arrayRemove([toDelete])
])
}
} else {
// array itself not found
print("items not found")
}
return nil // you can return things out of transactions but not needed here so return nil
} completion: { (_, error) in
if let error = error {
print(error)
} else {
print("transaction done")
}
}
The workaround I mentioned earlier is to bypass the token system altogether. And the simplest way to do that is to express time as an integer, using the Unix timestamp. This way, the date is stored as an integer in the database which is almost how you'd expect it to be stored anyway. This makes locating array elements that contain dates simpler because time on the client is now equal to time on the server. This is not the case with tokens because the actual date that is stored in the database, for example, is when the token is redeemed and not when it was created.
You can extend Date to conveniently convert dates to timestamps and extend Int to conveniently convert timestamps to dates:
typealias UnixTimestamp = Int
extension Date {
var unixTimestamp: UnixTimestamp {
return UnixTimestamp(self.timeIntervalSince1970 * 1_000) // millisecond precision
}
}
extension UnixTimestamp {
var dateObject: Date {
return Date(timeIntervalSince1970: TimeInterval(self / 1_000)) // must take a millisecond-precision unix timestamp
}
}
One last thing is that in my example, I located the element to delete by its number field (I used your data), which I assumed to be a unique identifier. I don't know the nature of these elements and how they are uniquely identified so consider the filter predicate in my code to be purely an assumption.
I need to merge two queries with firebase firestore and then order the results using the timestamp field of the documents.
Online I didn't find much information regarding Swift and Firestore.
This is what I did so far:
db.collection("Notes").whereField("fromUid", isEqualTo: currentUserUid as Any).whereField("toUid", isEqualTo: chatUserUid as Any).getDocuments { (snapshot, error) in
if let error = error {
print(error.localizedDescription)
return
}
db.collection("Notes").whereField("fromUid", isEqualTo: self.chatUserUid as Any).whereField("toUid", isEqualTo: self.currentUserUid as Any).getDocuments { (snaphot1, error1) in
if let err = error1{
print(err.localizedDescription)
return
}
}
}
I added the second query inside the first one on completion but now I don't know how to merge them and order them through the field of timestamp.
On this insightful question It is explained that it's recommended to use a Task object but I don't find anything similar with swift.
There are many ways to accomplish this; here's one option.
To provide an answer, we have to make a couple of additions; first, we need somewhere to store the data retrieved from firebase so here's a class to contains some chat information
class ChatClass {
var from = ""
var to = ""
var msg = ""
var timestamp = 0
convenience init(withDoc: DocumentSnapshot) {
self.init()
self.from = withDoc.get("from") as! String
self.to = withDoc.get("to") as! String
self.msg = withDoc.get("msg") as! String
self.timestamp = withDoc.get("timestamp") as! Int
}
}
then we need a class level array to store it so we can use it later - perhaps as a tableView dataSource
class ViewController: NSViewController {
var sortedChatArray = [ChatClass]()
The setup is we have two users, Jay and Cindy and we want to retrieve all of the chats between them and sort by timestamp (just an Int in this case).
Here's the code that reads in all of the chats from one user to another creates ChatClass objects and adds them to an array. When complete that array is passed back to the calling completion handler for further processing.
func chatQuery(from: String, to: String, completion: #escaping( [ChatClass] ) -> Void) {
let chatsColl = self.db.collection("chats") //self.db points to my Firestore
chatsColl.whereField("from", isEqualTo: from).whereField("to", isEqualTo: to).getDocuments(completion: { snapshot, error in
if let err = error {
print(err.localizedDescription)
return
}
guard let docs = snapshot?.documents else { return }
var chatArray = [ChatClass]()
for doc in docs {
let chat = ChatClass(withDoc: doc)
chatArray.append(chat)
}
completion(chatArray)
})
}
Then the tricky bit. The code calls the above code which returns an array The above code is called again, returning another array. The arrays are combined, sorted and printed to console.
func buildChatArray() {
self.chatQuery(from: "Jay", to: "Cindy", completion: { jayCindyArray in
self.chatQuery(from: "Cindy", to: "Jay", completion: { cindyJayArray in
let unsortedArray = jayCindyArray + cindyJayArray
self.sortedChatArray = unsortedArray.sorted(by: { $0.timestamp < $1.timestamp })
for chat in self.sortedChatArray {
print(chat.timestamp, chat.from, chat.to, chat.msg)
}
})
})
}
and the output
ts: 2 from: Cindy to: Jay msg: Hey Jay, Sup.
ts: 3 from: Jay to: Cindy msg: Hi Cindy. Not much
ts: 9 from: Jay to: Cindy msg: Talk to you later
This is the first time I am using a Firestore Query and I'm struggling to parse the data. I normally use the same setup when I get documents (which works), but when I attach it to a query it does not work.
I am trying to query the database for the shop most visited, so I can later set it as favourite.
My Code:
func findFavouriteShop(completed: #escaping ([String]) -> Void)
{
// Variables
let dispatch = DispatchGroup()
var dummyDetails = [String]()
// References
let db = Firestore.firestore()
let userID = Auth.auth().currentUser?.uid
let groupCollectionRef = String("visits-" + userID! )
// Query the database for the document with the most counts
dispatch.enter()
db.collectionGroup(groupCollectionRef).order(by: "count", descending: true).limit(to: 1).getDocuments { (snapshot, error) in
if let err = error {
debugPrint("Error fetching documents: \(err)")
}
else {
print(snapshot)
guard let snap = snapshot else {return}
for document in snap.documents {
let data = document.data()
// Start Assignments
let shopName = data["shopName"] as? String
let count = data["count"] as? String
// Append the dummy array
dummyDetails.append(shopName!)
dummyDetails.append(count!)
}
dispatch.leave()
}
dispatch.notify(queue: .main, execute: {
print("USER number of documents appended: \(dummyDetails.count)")
completed(dummyDetails)}
)
}
Using Print statements it seems as if the guard statement kicks the function out. The processor does not reach the for-loop to do the assignments. When I print the snapshot it returns an empty array.
I am sure I have used the wrong notation, but I'm just not sure where.
There's a lot to comment on, such as your choice of collection groups over collections (maybe that's what you need), why you limit the results to one document but feel the need to query a collection, the naming of your collections (seems odd), the query to get multiple shops but creating a function that only returns a single shop, using a string for a count property that should probably be an integer, and using a string array to return multiple components of a single shop instead of using a custom type.
That said, I think this should get you in the right direction. I've created a custom type to show you how I'd start this process but there's a lot more work to be done to get this where you need it to be. But this is a good starting point. Also, there was no need for a dispatch group since you weren't doing any additional async work in the document parsing.
class Shop {
let name: String // constant
var count: Int // variable
init(name: String, count: Int) {
self.name = name
self.count = count
}
}
func findFavouriteShops(completion: #escaping (_ shops: [Shop]?) -> Void) {
guard let userID = Auth.auth().currentUser?.uid else {
completion(nil)
return
}
var temp = [Shop]()
Firestore.firestore().collection("visits-\(userID)").order(by: "count", descending: true).limit(to: 1).getDocuments { (snapshot, error) in
guard let snapshot = snapshot else {
if let error = error {
print(error)
}
completion(nil)
return
}
for doc in snapshot.documents {
if let name = doc.get("shopName") as? String,
let count = doc.get("count") as? String {
let shop = Shop(name: name, count: count)
temp.append(Shop)
}
}
completion(temp)
}
}
You can return a Result type in this completion handler but for this example I opted for an optional array of Shop types (just to demonstrate flexibility). If the method returns nil then there was an error, otherwise there are either shops in the array or there aren't. I also don't know if you're looking for a single shop or multiple shops because in some of your code it appeared you wanted one and in other parts of your code it appeared you wanted multiple.
findFavouriteShops { (shops) in
if let shops = shops {
if shops.isEmpty {
print("no error but no shops found")
} else {
print("shops found")
}
} else {
print("error")
}
}
I am still new in swift development, my problem is, I have Firestore structure as below:
the problem is to display the list of title from firestore into a uipicker, I need to get data into an array like below:
[firsProgramme, secondProgramme, thirdProgramme]
I managed to display all the "title" from firestore in the string, not in the array
below is the code:
func getprogram() {
let db = Firestore.firestore()
db.collection("Programme").getDocuments()
{
(querySnapshot, err) in
if let err = err
{
print("Error getting documents: \(err)");
}
else
{
for document in querySnapshot!.documents {
let data = document.data()
let program = data["title"] as? String ?? ""
// let agencyId = document.documentID
print(program)
//print("\(document.documentID) => \(document.data())");
}
}
}
}
result print(program) return as below :
firstprogramme
secondprogramme
thirdprogramme
the other part for UIPicker is already being managed well.
Thanks in advance.
In you class create an array variable to hold information about your programs:
var programsArray: [String] = []
When reading data from Firebase, instead of print(program) use programsArray.append(program). Call UIPickerView reload function after you have all data.
DispatchQueue.main.async {
self.your_picker_view.reloadAllComponents()
}
And of course, use this array inside your pickerview datasource methods.