How I can parse firebase realtime database?
So far my code is:
var ref: DatabaseReference!
ref = Database.database().reference()
ref.child("data").observe(.childAdded) { (snapshot) in
print("snapshot = \(snapshot)")
}
I can not enter the condition.
print("url = \(ref.url)")
url = "https://gdenamaz.firebaseio.com"
this variant don't work too
var ref: DatabaseReference!
ref = Database.database().reference().child("data")
ref.observeSingleEvent(of: .value) { (snapshot) in
for data in snapshot.children {
print("data = \(data)")
}
}
To reference the official docs -
refHandle = postRef.observe(DataEventType.value, with: { (snapshot) in
let postDict = snapshot.value as? [String : AnyObject] ?? [:]
// ...
})
You want to be looking for the snapshot.value not snapshot.children
A further example
let userID = Auth.auth().currentUser?.uid
ref.child("users").child(userID!).observeSingleEvent(of: .value, with: { (snapshot) in
// Get user value
let value = snapshot.value as? NSDictionary
let username = value?["username"] as? String ?? ""
let user = User(username: username)
// ...
}) { (error) in
print(error.localizedDescription)
}
also, .childAdded will only trigger when a child is added. IE, nothing will happen until you actually change something in that node reference.
Related
let userId = Auth.auth().currentUser?.uid
Database.database().reference().child("Employess").child(userId!).observeSingleEvent(of: .value, with: { (snapshot) in
// Get user value
let value = snapshot.value as? NSDictionary
//print(value)
let Name = value?["name"] as? String
print(Name)
// ...
}) { (error) in
print(error.localizedDescription)
}
How do I get data from a child deeper into a database that has an unknown name?
My example structure is below.
This code works (to get the snapshot data) but I am hardcoding the second child. I will not always know this value (Bus 1).
let ref = FIRDatabase.database().reference()
let usersRef = ref.child("Trips").child("Bus 1")
usersRef.observeSingleEvent(of: .value, with: { (snapshot) in
for snap in snapshot.children {
let userSnap = snap as! FIRDataSnapshot
let uid = userSnap.key //the uid of each user
let userDict = userSnap.value as! [String:AnyObject] //child data
let personOn = userDict["getOn"] as! String
print("key = \(uid) is at getOn = \(personOn)")
}
})
This will print:
key = Stop 1 is at getOn = 3
key = Stop 2 is at getOn = 7
Should I be structuring this differently? Flatter?
Thanks and let me know of any questions.
This is a more preferable way as I have a class for TripDetails which goes into an array to load into the table. But again, I do not know what the second child's name is.
FIRDatabase.database().reference().child("Trips").child("Bus 1").observe(.childAdded, with: { (snapshot) in
if let dictionary = snapshot.value as? [String: AnyObject] {
let trip = TripDetails()
trip.setValuesForKeys(dictionary)
self.trips.append(trip)
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
print(snapshot)
}, withCancel: nil)
I'm still not super sure what data you want exactly. If all you want is all the data you can just do this.
let ref = FIRDatabase.database().reference().child("Trips")
ref.observeSingleEvent(of: .value, with: { snapshot in
let enumerator = snapshot.children
while let bus = enumerator.nextObject() as? FIRDataSnapshot {
print("\(bus.key)")
let enumerator = bus.children
while let stop = enumerator.nextObject() as? FIRDataSnapshot {
let stopDict = stop.value as? [String: Any]
let uid = stop.key
let personOn = stopDict?["getOn"] as? String
print("key = \(uid) is at getOn = \(personOn)")
}
}
})
I'm trying to get a specific value from Firebase Database. I looked some of the documents such as Google's, but I couldn't do it. Here is the JSON file of the database:
{
"Kullanıcı" : {
"ahmetozrahat25" : {
"E-Mail" : "ahmetozrahat25#gmail.com",
"Yetki" : "user"
},
"banuozrht" : {
"E-Mail" : "banuozrahat#gmail.com",
"Yetki" : "user"
}
}
}
Swift Code:
ref?.child("Kullanıcı").child(userName.text!).observeSingleEvent(of: .value, with: { (snapshot) in
if let item = snapshot.value as? String{
self.changedName = item
}
})
I want to get E-Mail value of a user, not everybody's. How can I do that?
At last I found a solution. If I declare a var and try to use later it returns nil, but if I try use snapshot.value as? String it's ok. Here is a example I did.
ref: FIRDatabaseReference?
handle: FIRDatabaseHandle?
let user = FIRAuth.auth()?.currentUser
ref = FIRDatabase.database().reference()
handle = ref?.child("Kullanıcı").child((user?.uid)!).child("Yetki").observe(.value, with: { (snapshot) in
if let value = snapshot.value as? String{
if snapshot.value as? String == "admin"{
self.items.append("Soru Gönder")
self.self.tblView.reloadData()
}
}
})
In your code, the snapshot will contain a dictionary of child values. To access them, cast the snapshot.value as a Dictionary and then accessing the individual children is a snap (shot, lol)
ref?.child("Kullanıcı").child(userName.text!)
.observeSingleEvent(of: .value, with: { (snapshot) in
let userDict = snapshot.value as! [String: Any]
let email = userDict["E-Mail"] as! String
let yetki = userDict["Yetki"] as! String
print("email: \(email) yetki: \(yetki)")
})
Add the "E-Mail" child to the query.
ref?.child("Kullanıcı").child(userName.text!).child("E-Mail").observeSingleEvent(of: .value, with: { (snapshot) in
if let item = snapshot.value as? String{
self.changedName = item
}
})
I'm trying to retrieve specific data from just the currently logged in user. My data in my database looks like this:
For example, I want to just grab the full_name and save it in a variable userName. Below is what I'm using to grab my data
ref.queryOrderedByChild("full_name").queryEqualToValue("userIdentifier").observeSingleEventOfType(.ChildAdded, withBlock: { snapshot in
print(snapshot.value)
// let userName = snapshot.value["full_name"] as! String
})
Unfortunately, this is what my console prints.
I would appreciate any help :) Thank you!
It gives you that warning message indexOn because you are doing a query.
you should define the keys you will be indexing on via the .indexOn
rule in your Security and Firebase Rules. While you are allowed to
create these queries ad-hoc on the client, you will see greatly
improved performance when using .indexOn
As you know the name you are looking for you can directly go to that node, without a query.
let ref:FIRDatabaseReference! // your ref ie. root.child("users").child("stephenwarren001#yahoo.com")
// only need to fetch once so use single event
ref.observeSingleEventOfType(.Value, withBlock: { snapshot in
if !snapshot.exists() { return }
//print(snapshot)
if let userName = snapshot.value["full_name"] as? String {
print(userName)
}
if let email = snapshot.value["email"] as? String {
print(email)
}
// can also use
// snapshot.childSnapshotForPath("full_name").value as! String
})
Swift 4
let ref = Database.database().reference(withPath: "user")
ref.observeSingleEvent(of: .value, with: { snapshot in
if !snapshot.exists() { return }
print(snapshot) // Its print all values including Snap (User)
print(snapshot.value!)
let username = snapshot.childSnapshot(forPath: "full_name").value
print(username!)
})
{
"rules": {
"tbl_name": {
".indexOn": ["field_name1", "field_name2"]
},
".read": true,
".write": true
}
}
You can apply indexOn on any field. Add this json in rules security and rules tab.
Hope this works for you. :)
It retrieves logged in user data:
let ref = FIRDatabase.database().reference(fromURL: "DATABASE_URl")
let userID = FIRAuth.auth()?.currentUser?.uid
let usersRef = ref.child("users").child(userID!).observeSingleEvent(of: .value, with: { (snapshot) in
print(snapshot)
let ref = Database.database().reference().child("users/stephenwarren001#yahoo.com")
ref.observeSingleEvent(of: .value, with: { (snap : DataSnapshot) in
print("\(String(describing: snap.value))")
}) { (err: Error) in
print("\(err.localizedDescription)")
}
var refDatabase = DatabaseReference()
refDatabase = Database.database().reference().child("users");
let refUserIdChild = refDatabase.child("stephenwarren001#yahoo.com")
refUserIdChild.observeSingleEvent(of: .value, with: { snapshot in
if !snapshot.exists() { return }
print(snapshot) // Its print all values including Snap (User)
print(snapshot.value!)
if let tempDic : Dictionary = snapshot.value as? Dictionary<String,Any>
{
if let userName = tempDic["full_name"] as? String {
self.tfName.text = userName
}
if let email = tempDic["email"] as? String {
self.tfEmail.text = email
}
}
})
I have a Firebase resource that contains several objects and I would like to iterate over them using Swift.
What I expected to work is the following (according to the Firebase documentation)
https://www.firebase.com/docs/ios-api/Classes/FDataSnapshot.html#//api/name/children
var ref = Firebase(url:MY_FIREBASE_URL)
ref.observeSingleEventOfType(.Value, withBlock: { snapshot in
println(snapshot.childrenCount) // I got the expected number of items
for rest in snapshot.children { //ERROR: "NSEnumerator" does not have a member named "Generator"
println(rest.value)
}
})
So it seems there is a problem with Swift iterating over the NSEnumerator object returned by Firebase.
Help is really welcome.
If I read the documentation right, this is what you want:
var ref = Firebase(url: MY_FIREBASE_URL)
ref.observeSingleEvent(of: .value) { snapshot in
print(snapshot.childrenCount) // I got the expected number of items
for rest in snapshot.children.allObjects as! [FIRDataSnapshot] {
print(rest.value)
}
}
A better way might be:
var ref = Firebase(url: MY_FIREBASE_URL)
ref.observeSingleEvent(of: .value) { snapshot in
print(snapshot.childrenCount) // I got the expected number of items
let enumerator = snapshot.children
while let rest = enumerator.nextObject() as? FIRDataSnapshot {
print(rest.value)
}
}
The first method requires the NSEnumerator to return an array of all of the objects which can then be enumerated in the usual way. The second method gets the objects one at a time from the NSEnumerator and is likely more efficient.
In either case, the objects being enumerated are FIRDataSnapshot objects, so you need the casts so that you can access the value property.
Using for-in loop:
Since writing the original answer back in Swift 1.2 days, the language has evolved. It is now possible to use a for in loop which works directly with enumerators along with case let to assign the type:
var ref = Firebase(url: MY_FIREBASE_URL)
ref.observeSingleEvent(of: .value) { snapshot in
print(snapshot.childrenCount) // I got the expected number of items
for case let rest as FIRDataSnapshot in snapshot.children {
print(rest.value)
}
}
I have just converted the above answer to Swift 3:
ref = FIRDatabase.database().reference()
ref.observeSingleEvent(of: .value, with: { snapshot in
print(snapshot.childrenCount) // I got the expected number of items
for rest in snapshot.children.allObjects as! [FIRDataSnapshot] {
print(rest.value)
}
})
A better way might be:
ref = FIRDatabase.database().reference()
ref.observeSingleEvent(of: .value, with: { snapshot in
print(snapshot.childrenCount) // I got the expected number of items
let enumerator = snapshot.children
while let rest = enumerator.nextObject() as? FIRDataSnapshot {
print(rest.value)
}
})
This is pretty readable and works fine:
var ref = Firebase(url:MY_FIREBASE_URL)
ref.childByAppendingPath("some-child").observeSingleEventOfType(
FEventType.Value, withBlock: { (snapshot) -> Void in
for child in snapshot.children {
let childSnapshot = snapshot.childSnapshotForPath(child.key)
let someValue = childSnapshot.value["key"] as! String
}
})
ref = FIRDatabase.database().reference().child("exampleUsernames")
ref.observeSingleEvent(of: .value, with: { snapshot in
for rest in snapshot.children.allObjects as! [FIRDataSnapshot] {
guard let restDict = rest.value as? [String: Any] else { continue }
let username = restDict["username"] as? String
}
})
Firebase 4.0.1
Database.database().reference().child("key").observe(.value) { snapshot in
if let datas = snapshot.children.allObjects as? [DataSnapshot] {
let results = datas.flatMap({
($0.value as! [String: Any])["xxx"]
})
print(results)
}
}
Firebase 7.3.0
Database.database().reference().child("key").observe(.value) { snapshot in
if let datas = snapshot.children.allObjects as? [DataSnapshot] {
let results = datas.compactMap({
($0.value)
})
print(results)
}
}
If you have multiple keys/values, and want to return an array with dictionary elements, declare an array:
var yourArray = [[String: Any]]()
then change block body to this:
let children = snapshot.children
while let rest = children.nextObject() as? DataSnapshot, let value = rest.value {
self.yourArray.append(value as! [String: Any])
}