Updating values in Firebase - ios

func updateFirebase(){
myFun = thisIsMyFunTextView.text
IAm = iAmTextView.text
var profileKey = String()
profileRef.queryOrdered(byChild: "uid").queryEqual(toValue: userID).observe(.value, with:{
snapshot in
for item in snapshot.children {
guard let data = item as? FIRDataSnapshot else { continue }
guard let dict = data.value as? [String: Any] else { continue }
guard let profileKey = dict["profileKey"] else { continue }
self.profileRef.child(profileKey as! String).child("bodyOfIAM").setValue(IAm)
self.profileRef.child(profileKey as! String).child("bodyOfThisIsMyFun").setValue(myFun)
}
})
}
#IBAction func backButtonClicked(_ sender: Any) {
updateFirebase()
DispatchQueue.main.asyncAfter(deadline: .now() + 4, execute: {
self.dismiss(animated: true)
})
}
myFun and IAm are successfully defined by the changes to the textviews by the user. I can't extract the childByAutoID value without triggering this for in loop that does not end once called, continuing even as a new view controller is presented. The "bodyOfThisIsMyFun" vacillates between the old value and the new value during this loop while the "bodyOfIAM" gets correctly redefined right away and stays that way like it should. How do I get the extracted new values to replace the old values here?

I needed to add this line of code at the end of the for...in statement:
self.profileRef.removeAllObservers()

Related

How can you ensure that cells are not duplicated when the device is overwhelmed by code from the previous page?

I have a problem that only occurs when page A has to run a massive amount of code and the user goes to page B before all the A page code is finished. In these instances, sometimes cells get duplicated(ie, say page B must be : User H in top, user F below him. Instead there are two Hs followed by two Fs below them).
Below is the relevant code of page B, but I am fairly certain the problem does not lie there. Why?: Because I changed the array that gets displayed [H,F] to a set, so according to the code, there should never be an instance like [H,H,F,F]
///Part1: code that gets called from viewdidLoad
var peppi = [Usery]()
func printPersonInfo(uid: String) {
self.handleA = thisUser.observe(DataEventType.value, with: { snapshot in
...
myPeopleRef44.queryLimited(toLast: 30).observeSingleEvent(of: .value, with: { [self] snapshot in
let uniqueArray = snapshot.children.allObjects as! [DataSnapshot]
let peopleArray = Array(Set(uniqueArray))
for person in peopleArray where uid == person.value as? String {
...
func decode(autoId: String) -> TimeInterval {
}
return TimeInterval(exactly: timestamp)!
}
...
if Calendar.current.isDateInToday(date){
let p = Usery(...)
peppi.append(p)
}
}
DispatchQueue.main.async {
self.peppi.sort { ($0.self.time1 ?? 0) > ($1.self.time1 ?? 0)
}
print(self.peppi, "lo")
self.table.reloadData()
}
})
})
}
/// Part: 2 In viewDidLoad, code that calls the function printPersonInfo
handle = myPeopleRef.queryLimited(toLast: 30).observe(DataEventType.value, with: { snapshot in
func decode(autoId: String) -> TimeInterval {
..
return …
}
let uniqueArray1 = snapshot.children.allObjects as! [DataSnapshot]
let peopleArray = Array(Set(uniqueArray1))
for person4 in peopleArray where uid == Auth.auth().currentUser?.uid {
self.dg.enter()
self.dg.leave()
self.dg.notify(queue: .main) {
let date = Date(timeIntervalSince1970: TimeInterval(time11)/1000.0)
print(date,"pdate")
if Calendar.current.isDateInToday(date){
self.printPersonInfo(uid: personUid)
}
}
}
DispatchQueue.main.asyncAfter(deadline: .now() + 4) {
let ref = Database.database().reference().child("people")
ref.removeObserver(withHandle: handle)
ref.removeObserver(withHandle: self.handleA)
}
})

Call reloadData() in the right place

I'm trying to fetch data from firebase and pass to tableview.
// Model
import UIKit
import Firebase
struct ProfInfo {
var key: String
var url: String
var name: String
init(snapshot:DataSnapshot) {
key = snapshot.key
url = (snapshot.value as! NSDictionary)["profileUrl"] as? String ?? ""
name = (snapshot.value as! NSDictionary)["tweetName"] as? String ?? ""
}
}
// fetch
var profInfo = [ProfInfo]()
func fetchUid(){
guard let uid = Auth.auth().currentUser?.uid else{ return }
ref.child("following").child(uid).observe(.value, with: { (snapshot) in
guard let snap = snapshot.value as? [String:Any] else { return }
snap.forEach({ (key,_) in
self.fetchProf(key: key)
})
}, withCancel: nil)
}
func fetchProf(key: String){
var outcome = [ProfInfo]()
ref.child("Profiles").child(key).observe(.value, with: { (snapshot) in
let info = ProfInfo(snapshot: snapshot)
outcome.append(info)
self.profInfo = outcome
self.tableView.reloadData()
}, withCancel: nil)
}
//tableview
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return profInfo.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "followCell", for: indexPath) as! FollowingTableViewCell
cell.configCell(profInfo: profInfo[indexPath.row])
return cell
}
However it returns one row but profInfo actually has two rows. when I implement print(self.profInfo) inside fetchProf it returns two values. But after passed to tableview, it became one. I'm not sure but I guess the reason is that I put reloadData() in the wrong place because I hit break point and reloadData() called twice. So, I think profInfo replaced by new value. I called in different places but didn't work. Am I correct? If so, where should I call reloadData()? If I'm wrong, how can I fix this? Thank you in advance!
You need to append the new data to the profinfo array. Simply replace the fetchProf method with this:-
func fetchProf(key: String){
var outcome = [ProfInfo]()
ref.child("Profiles").child(key).observe(.value, with: { (snapshot) in
let info = ProfInfo(snapshot: snapshot)
outcome.append(info)
self.profInfo.append(contentOf: outcome)
Dispatch.main.async{
self.tableView.reloadData()
}
} , withCancel: nil)
}
self.tableView.reloadData() must be called from the main queue. Try
DispatchQueue.main.async {
self.tableView.reloadData()
}
if you notice one thing in the following function you will see
func fetchProf(key: String){
var outcome = [ProfInfo]()
ref.child("Profiles").child(key).observe(.value, with: { (snapshot) in
let info = ProfInfo(snapshot: snapshot)
outcome.append(info)
//Here
/You are replacing value in self.profInfo
//for the first time when this is called it results In First profile info
//When you reload here first Profile will be shown
//Second time when it is called you again here replaced self.profInfo
//with second Outcome i.e TableView reloads and output shown is only second Profile
//you had initialised a Array self.profInfo = [ProfInfo]()
//But you just replacing array with Single value Actually you need to append data
// I think here is main issue
self.profInfo = outcome
//So try Appending data as
//self.profInfo.append(outcome) instead of self.profInfo = outcome
//Then reload TableView to get both outputs
self.tableView.reloadData()
}, withCancel: nil)
}
Table view showing one content because when table view reloaded then profile info not combine all data. You need to reload the table view after combining all data. This will help you.
// fetch
var profInfo = [ProfInfo]()
func fetchUid(){
guard let uid = Auth.auth().currentUser?.uid else{ return }
ref.child("following").child(uid).observe(.value, with: { (snapshot) in
guard let snap = snapshot.value as? [String:Any] else { return }
snap.forEach({ (key,_) in
self.fetchProf(key: key)
})
// When all key fetched completed the just reload the table view in the Main queue
Dispatch.main.async{
self.tableView.reloadData()
}
}, withCancel: nil)
}
func fetchProf(key: String){
ref.child("Profiles").child(key).observe(.value, with: { (snapshot) in
let info = ProfInfo(snapshot: snapshot)
self.profInfo.append(info) // Here just add the outcome object to profileinfo
}, withCancel: nil)
}
This way no need to handle another array.

Completion handler Firebase observer in Swift

I am making a completion handler for a function which will return a list of objects. When it return value for first time, it works well. But when any change happen into firebase database and again observe gets called, array size gets doubled up. Why it's getting doubled up?
func getStadiums(complition: #escaping ([Stadium]) -> Void){
var stadiums: [Stadium] = []
let stadiumRef = Database.database().reference().child("Stadium")
stadiumRef.observe(.value, with: { (snapshot) in
for snap in snapshot.children {
guard let stadiumSnap = snap as? DataSnapshot else {
print("Something wrong with Firebase DataSnapshot")
complition(stadiums)
return
}
let stadium = Stadium(snap: stadiumSnap)
stadiums.append(stadium)
}
complition(stadiums)
})
}
And calling like this
getStadiums(){ stadiums
print(stadiums.count) // count gets doubled up after every observe call
}
The code you're using declares stadiums outside of the observer. This means any time a change is made to the value of the database reference, you're appending the data onto stadiums without clearing what was there before. Make sure to remove the data from stadiums before appending the snapshots again:
func getStadiums(complition: #escaping ([Stadium]) -> Void){
var stadiums: [Stadium] = []
let stadiumRef = Database.database().reference().child("Stadium")
stadiumRef.observe(.value, with: { (snapshot) in
stadiums.removeAll() // start with an empty array
for snap in snapshot.children {
guard let stadiumSnap = snap as? DataSnapshot else {
print("Something wrong with Firebase DataSnapshot")
complition(stadiums)
return
}
let stadium = Stadium(snap: stadiumSnap)
stadiums.append(stadium)
}
complition(stadiums)
})
}
This line stadiumRef.observe(.value, with: { (snapshot) in ... actually adding an observer that will be called everytime your stadium data is changed.
Because you called it twice by using getStadiums(){ stadiums ..., the total observer added will be 2.
That makes the line stadiums.append(stadium) called twice in the second call.
My suggestion would be to use stadiumRef.observe() once without calling it from getStadiums().
Create a Model as below
class OrderListModel: NSObject {
var Order:String?
var Date:String?
}
Use the below code in the view controller and you should be able to see content in your tableview
func getOrdersData() {
self.orderListArr.removeAll()
let ref = Database.database().reference().child(“users”).child(user).child("Orders")
ref.observe(.childAdded, with: { (snapshot) in
print(snapshot)
guard let dictionary = snapshot.value as? [String : AnyObject] else {
return
}
let orderObj = OrderModel()
orderObj.Order = dictionary[“Order”] as? String
orderObj.Date = dictionary[“Date”] as? String
self.orderListArr.append(orderObj)
self.tableView.delegate = self
self.tableView.dataSource = self
self.tableView.reloadData()
}, withCancel: nil)
}
func ListenForChildrenAdded() {
let registerToListenTo = "YourPathHere"
ref.child(registerToListenTo).observeSingleEvent(of: .value) { (snapshot) in
let initialChildren = snapshot.childrenCount
var incrementer = 0
ref.child(registerToListenTo).observe(.childAdded, with: { (snapshot) in
incrementer += 1
print("snapshot: \(snapshot.key) #\(incrementer)")
if incrementer == initialChildren {
print("-> All children found")
} else if incrementer > initialChildren {
print("-> Child Was Added - Run Some Code Here")
}
})
}}

Popup alert not showing when a match is not found in database

I'm using this function to check to see if a certain handle exists in my database. It works fine for the most part - if the handle exists, it updates the table view to display that user. However if there is no match for the handle entered, my alert view is not showing up.
// Search DB for matching handles
#IBAction func searchHandleButtonPressed(_ sender: Any) {
if let handleToSearch = handleSearchTextField.text?.lowercased() {
let databaseRef = FIRDatabase.database().reference()
databaseRef.child("users").queryOrdered(byChild: "lowercaseHandle").queryEqual(toValue: handleToSearch).observeSingleEvent(of: .value, with: { (snapshot) in
if let snapDict = snapshot.value as? [String:AnyObject] {
for each in snapDict{
let key = each.key
let handle = each.value["handle"] as! String
self.returnedHandles.removeAll()
self.returnedHandles.append(handle)
let pic = each.value["profilePicture"] as! String
self.returnedUsersProfilePic = pic
self.returnedUsersUID = key
if handle.lowercased() != handleToSearch {
self.noHandleFoundAlert()
}
if handle != "" {
DispatchQueue.main.async {
self.getFriendsInfo()
self.tableView.reloadData()
}
}
}
}
}, withCancel: {(Err) in
// print(Err.localizedDescription)
})
}
}
I put the alert in the loop as:
if handle.lowercased() != handleToSearch {
self.noHandleFoundAlert()
}
But obviously this isn't the correct approach as it isn't working. If I enter a random string of characters, or a handle that I know isn't in use, the alert doesn't come up. Where else would I put the alert so it will show up if there's no match?
The snapshot will be converted to an empty dictionary with your current code.
Before converting the snapshot.value to a Dictionary, check if it exists with snapshot.exists(): https://firebase.google.com/docs/reference/ios/firebasedatabase/api/reference/Classes/FIRDataSnapshot#-exists
You first have to check if the query you made, has data. So you have a
.hasChild("handle")
it returns a boolean, so when is true you do the loop, else notified user.

Using UpdateChildValue to Edit from Firebase

I am wanting to update the child values after editing inside the textfields.
At the moment I have this action:
#IBAction func updateAction(_ sender: Any) {
guard let itemNameText = itemName.text, let itemDateText = itemDate.text else { return }
guard itemNameText.characters.count > 0, itemDateText.characters.count > 0 else {
print("Complete all fields")
return
}
let uid = FIRAuth.auth()?.currentUser?.uid
let key = item.ref!.key
let itemList = Item(itemName: itemNameText, itemDate: itemDateText, uid: uid!)
let editItemRef = databaseRef.child("/usersList/\(key)")
editItemRef.updateChildValues(itemList.toAnyObject())
print("edited")
}
I was following this tutorial but he seems to use the username, and as I only have the email or uid (userID) as authentication I thought I'd use the uid.
This is my toAnyObject function inside my class:
func toAnyObject() -> [String: AnyObject] {
return ["itemName": itemName as AnyObject, "itemDate": itemDate as AnyObject, "userID": userID as AnyObject]
}
When I run the breakpoint it does show the edited value of the item however the update doesn't appear to be performing.
Just to be extra safe, try dropping the leading slash from your path:
databaseRef.child("usersList/\(key)")
…and try printing the Error returned by Firebase, if any:
editItemRef.updateChildValues(itemList.toAnyObject()) {
(error, _) in
if let error = error {
print("ERROR: \(error)")
} else {
print("SUCCESS")
}
Edit. We found out he was using the wrong database path. The right one is:
databaseRef.child("users").child(uid!).child("usersList/‌​\(key)")

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