I am able to successfully write data from my application to my firebase real-time database. I cannot retrieve the data and display it in a UIViewController.
I have search stack, YouTube and firebase docs and no luck. I printed out the count and it returns 0. I believe the For loop isn't iterating or its not appending to my array correctly. I have trie force wrapping and unwrapping refRepairs, and placing databaseHandle in from of it.
override func viewDidLoad() {
super.viewDidLoad()
refRepairs = Database.database().reference().child("repairs");
//observing the data changes
refRepairs!.child("repairs").observe(DataEventType.value, with: { (snapshot) in
//if the reference have some values
if snapshot.childrenCount > 0 {
//clearing the list
self.repairList.removeAll()
//iterating through all the values
for repairs in snapshot.children.allObjects as! [DataSnapshot] {
//getting values
let repairObject = repairs.value as? [String: AnyObject]
let brand = repairObject?["brand"]
let id = repairObject?["id"]
let modelNumber = repairObject?["modelNumber"]
//creating artist object with model and fetched values
let repair = RepairModel(id: id as! String?, brand: brand as! String?, modelNumber: modelNumber as! String?)
//appending it to list
print(snapshot.childrenCount)
self.repairList.append(repair)
}
//reloading the tableview
self.doListTableView.reloadData()
}
})
}
I made the changes and it was working!!! Now, I am trying to add records to the database by uid, and I have successfully done it. Now I have the same problem where I can't display the records. I printed the count and it returns 1 record which is correct. Here is the new code.
override func viewDidLoad() {
super.viewDidLoad()
refRepairs = Database.database().reference().child("repairs");
//observing the data changes
//refRepairs!.child("uid").observe(DataEventType.value, with: { (snapshot) in
//observing the data changes
refRepairs!.observe(DataEventType.value, with: { (snapshot) in
//if the reference have some values
if snapshot.childrenCount > 0 {
//clearing the list
self.repairList.removeAll()
//iterating through all the values
for repairs in snapshot.children.allObjects as! [DataSnapshot] {
//getting values
let repairObject = repairs.value as? [String: AnyObject]
let brand = repairObject?["brand"]
let uid = repairObject?["uid"]
let id = repairObject?["id"]
let modelNumber = repairObject?["modelNumber"]
//creating artist object with model and fetched values
let repair = RepairModel(uid: uid as! String?, id: id as! String?, brand: brand as! String?, modelNumber: modelNumber as! String?)
//appending it to list
print(snapshot.childrenCount)
self.repairList.append(repair)
}
//reloading the tableview
self.doListTableView.reloadData()
}
})
}
You are looking another second child called repairs when you are "observing the data changes". Try this:
override func viewDidLoad() {
super.viewDidLoad()
refRepairs = Database.database().reference().child("repairs");
//observing the data changes
refRepairs!.observe(DataEventType.value, with: { (snapshot) in
...
If that don't work. Use the observeSingleEvent method from Firebase
Related
I am wanting to capture all the values in my childByAutoId in firebase. Essentially, it stores all the items that a person has shortlisted. However, I do not seem to be capturing this, and I assume it is because I am not calling the snapshot correctly to factor the auto id's.
Database:
userID
-> Favourited
-> Auto Id
-> itemName: x
-> Auto Id
-> itemName: x
-> Auto Id
-> itemName: x
Code:
func retrieveItems() {
guard let userId = Auth.auth().currentUser?.uid else { return }
let ref = Database.database().reference().child("users/\(userId)/Favourited")
ref.observe(.value, with: { (snapshot) in
if snapshot.childrenCount>0 {
self.favUsers.removeAll()
for likes in snapshot.children.allObjects as! [DataSnapshot] {
let likesObject = likes.value as? [String: AnyObject]
let itemName = likesObject!["itemName"]
let likesList = Names(id: likes.key, itemName: itemName as! String?)
self.favUsers.append(likesList)
}
} else {
print("not yet")
}
})
self.favList.reloadData()
}
Could someone have a look and let me know what I may be doing wrong? Thank you!
This happens because Firebase loads data asynchronously, and right now you're calling reloadData before the self.favUsers.append(likesList) has ever run.
The call to reloadData needs to be inside the close/completion handler that is called when the data comes back from Firebase:
ref.observe(.value, with: { (snapshot) in
if snapshot.childrenCount>0 {
self.favUsers.removeAll()
for likes in snapshot.children.allObjects as! [DataSnapshot] {
let likesObject = likes.value as? [String: AnyObject]
let itemName = likesObject!["itemName"]
let likesList = Names(id: likes.key, itemName: itemName as! String?)
self.favUsers.append(likesList)
}
self.favList.reloadData() // 👈 Move this here
} else {
print("not yet")
}
})
I also recommend checking out some of these answers asynchronous data loading in Firebase.
I have this database (see the link above with the image) and a code with a path, that leads to the destination using:
databaseReference.child("users").child(currentUser!.uid).child("todo-list")
Under the first node "users", the next level is a keyvalue for userID, and later there are more sub-levels "todo-list" etc.
I would like to fetch the data from all uid available. How can I make the query?
Here is the code:
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
databaseReference = Database.database().reference()
currentUser = Auth.auth().currentUser
let todoListRef = databaseReference.child("users").child(currentUser!.uid).child("todo-list")
todoListRef.observe(DataEventType.value, with: { (DataSnapshot) in
self.itemsToLoad.removeAll()
let enumerator = DataSnapshot.children
while let todoItem = enumerator.nextObject() as? DataSnapshot
{
let item = todoItem.value as AnyObject
self.itemsToLoad.append(item)
}
self.itemsToLoad = self.itemsToLoad.reversed()
self.tableView.reloadData()
})
}
It's quite similar to the code you already have. Instead of observing /users/$uid, you observe the entire /users node. And then you add an extra loop in the closure, to iterate over all the users.
So:
let usersRef = databaseReference.child("users")
usersRef.observe(DataEventType.value, with: { (usersSnapshot) in
let userEnumerator = usersSnapshot.children
while let user = userEnumerator.nextObject() as? DataSnapshot {
let uid = user.key
let todoEnumerator = user.childSnapshot(forPath: "todo-list").children
while let todoItem = todoEnumerator.nextObject() as? DataSnapshot {
let item = todoItem.value as AnyObject
self.itemsToLoad.append(item)
}
}
})
The added while loops over the users, while the inner while loops over the todo's for each user. I removed the code related to the table view, since what you want to do there doesn't depend on Firebase.
Im successfully getting data from Firebase but I can't manage to push it into array to use. My database is as follows:
users
-Wc1EtcYzZSMPCtWZ8wRb8RzNXqg2
-email : "mike#gmail.com"
-lists
-LJiezOzfDrqmd-hnoH-
-owner: Wc1EtcYzZSMPCtWZ8wRb8RzNXqg2
-LJif-UgPgbdGSHYgjY6
-owner: Wc1EtcYzZSMPCtWZ8wRb8RzNXqg2
shopping-lists
-LJh6sdBJtBCM7DwxPRy
-name: "weekly shopping"
-owner: "mike#gmail.com"
I have a home page after login that shows existing shopping lists on table if they exist. On viewDidLoad() I get shopping list IDs from the user and use those IDs as a reference to get details from shopping-lists.
However, I cant manage to save these data into an array as it gets deleted after closure. How can I do that in a clean way?
override func viewDidLoad() {
super.viewDidLoad()
SVProgressHUD.show()
tableView.allowsMultipleSelectionDuringEditing = false
// Sets user variable - must have
Auth.auth().addStateDidChangeListener { auth, user in
guard let user = user else { return }
self.user = User(authData: user)
// If new user, write into Firebase
self.usersRef.observeSingleEvent(of: .value, with: { snapshot in
if !snapshot.hasChild(self.user.uid) {
self.usersRef.child(user.uid).setValue(["email": user.email!])
}
})
// Get shopping lists data from "users/lists"
self.usersRef.child(user.uid).child("lists").observe(.value, with: { snapshot in
// Get list IDs
if snapshot.exists() {
if let result = snapshot.children.allObjects as? [DataSnapshot] {
for child in result {
self.listNames.append(child.key)
}
}
}
// Use list IDs - to get details
for item in self.listNames {
let itemRef = self.shoppingListsRef.child(item)
itemRef.observeSingleEvent(of: .childAdded, with: { (snapshot) in
if let value = snapshot.value as? [String: Any] {
let name = value["name"] as? String ?? ""
let owner = value["owner"] as? String ?? ""
let shoppingList = ShoppingList(name: name, owner: owner)
self.items.append(shoppingList)
}
})
}
})
self.tableView.reloadData()
SVProgressHUD.dismiss()
}
}
(the question is a bit unclear so several parts to this answer to cover all possibilities. This is Swift 4, Firebase 4/5)
You don't really need to query here since you know which nodes you want by their key and they will always be read in the in order of your listNames array. This assumes self.listNames are the keys you want to read in.
for item in listNames {
let itemRef = shoppingListsRef.child(item)
itemRef.observe(.value, with: { (snapshot) in
if let value = snapshot.value as? [String: Any] {
let name = value["name"] as? String ?? ""
let owner = value["owner"] as? String ?? ""
print(name, owner)
}
})
}
Generally, queries are used when you are searching for something within a node - for example if you were looking for the node that contained a child name of 'weekly shopping'. Other than that, stick with just reading the nodes directly as it's faster and has less overhead. Keep reading...
I also removed the older NSDictionary and went with the Swift [String: Any] and modified your error checking
However, the real issue is reading that node with an .observe by .value. Remember that .value reads in all children of the node and then the children need to be iterated over to get each separate DataSnapshot. Also, .observe leaves an observer on the node notifying the app of changes, which I don't think you want. So this will answer the question as posted, (and needs better error checking)
for item in listNames {
let queryRef = shoppingListsRef
.queryOrdered(byChild: "name")
.queryEqual(toValue: item)
queryRef.observe(.value, with: { (snapshot) in
for child in snapshot.children { //even though there is only 1 child
let snap = child as! DataSnapshot
let dict = snap.value as! [String: Any]
let name = dict["name"] as? String ?? ""
let owner = dict["owner"] as? String ?? ""
print(name, owner)
}
})
}
And the answer...
This is probably more what you want...
for item in listNames {
let queryRef = shoppingListsRef
.queryOrdered(byChild: "name")
.queryEqual(toValue: item)
queryRef.observeSingleEvent(of: .childAdded, with: { snapshot in
let dict = snapshot.value as! [String: Any]
let name = dict["name"] as? String ?? ""
let owner = dict["owner"] as? String ?? ""
print(name, owner)
})
}
note the .childAdded instead of .value which presents the snapshot as a single DataSnapshot and doesn't need to be iterated over and the .observeSingleEvent which does not leave an observer attached to each node.
Edit
Based on additonal information, it would be best too change the structure to this
shopping-lists
-LJh6sdBJtBCM7DwxPRy
-name: "weekly shopping"
-uid: "Wc1EtcYzZSMPCtWZ8wRb8RzNXqg2"
and then when the user logs in just query the shopping lists node for any uid that's theirs.
i am attempting to retrieve a list of Posts ("Planits - in my apps language") from firebase. My goal is to display a specific users posts within a table view on their profile. I have written a function to retrieves posts and query them by a sender ID so that the user see's their posts on their profile. But at the end of the query when i try to print out the appended array, i keep getting an empty array, so i can not go further on to populate the table view. Please any suggestions on where i went wrong, attached is a screen shot of my firebase nodes and the function i wrote. thanks
func retrievePost(){
ref = Database.database().reference()
let myPlanitsRef = self.ref.child("planits")
let query = myPlanitsRef.queryOrdered(byChild: "senderId").queryEqual(toValue: "uid")
print(query)
query.observeSingleEvent(of: .value, with: { (snapshot) in
if snapshot.exists() {
for child in snapshot.children {
let snap = child as! DataSnapshot
print(DataSnapshot.self)
let dict = snap.value as! [String: Any]
let myPostURL = dict["images"] as! String
self.images.append(myPostURL)
}
//print(myPostURL) - DOES NOT PRING ANYTHING
//print(self.images) - DOES NOT PRING ANYTHING
}
}) { (error) in
print(error)
}
}
override func viewDidLoad() {
super.viewDidLoad()
retrievePost()
print(images) // PRINTS []
I am beginner and I would like to use swift as my programming language.
user can add register users and transfer money to each other, therefore when user type the photo number and email, the app can check if the typed number is registered in the firebase system
Any simple way to search if the user exist, thanks a lot
Here's the structure of the database
var ref: DatabaseReference!
var tref: DatabaseReference!
var handle : DatabaseHandle!
var usersArray = [NSDictionary?]()
var filteredUsers = [NSDictionary?]()
var user : NSDictionary?
override func viewDidLoad() {
super.viewDidLoad()
self.picker.isHidden = true
tref = Database.database().reference()
ref = Database.database().reference()
self.handle = self.ref?.child("users").child((Auth.auth().currentUser?.uid)!).child("contact").observe(.childAdded, with: { (snapshot) in
if let item = snapshot.value as? String {
self.pickerdata.append(item)
self.picker.reloadAllComponents()
}
})
self.picker.delegate = self
self.picker.dataSource = self
tref.child("users").queryOrdered(byChild: "phone").observe(.childAdded, with: {(snapshot) in
self.usersArray.append(snapshot.value as? NSDictionary)
})
print(usersArray.count)
}
#IBAction func ContactChange(_ sender: UITextField) {
filteredContent(searchText: contactText.text!)
print(filteredUsers.count)
print(usersArray.count)
print("ARRAY")
}
func filteredContent(searchText: String){
self.filteredUsers = self.usersArray.filter{ user in
let username = user!["phone"] as? String
return (username?.lowercased().contains(searchText.lowercased()))!
}
}
func findUsers(text: String){
self.handle = ref.child("users").queryOrdered(byChild: "phone").queryStarting(atValue: contactText.text!).queryEnding(atValue: contactText.text!+"\u{f8ff}").observe(.value, with: { snapshot in
if let item = snapshot.value as? String {
self.contact.append(item)
} else{
print("error")
}
})
}
The code above doesn't work much. Thanks so much for helping
The question is a little unclear but I think what the OP is asking is:
how to see if a user exists by their phone number?
If that's what's being asked, a node can be retrieved by query'ing for a child of that node. For example, let's create a query on the users node to find the child that contains the name: Kam querying by phone
let usersRef = firebaseRef.child("users")
let query = usersRef.queryOrdered(byChild: "phone").queryEqual(toValue: "2330504")
query.observeSingleEvent(of: .value) { (snapshot) in
if snapshot.exists() {
//need to iterate in case we find more than one match
for child in snapshot.children {
let snap = child as! DataSnapshot
let dict = snap.value as! [String: Any]
let name = dict["name"] as! String
print("found \(name)")
}
} else {
print("not found")
}
}
When this code is run it would print
found Kam
assuming the phone number is 2330504