Get data from Firebase - ios

I am trying to get data from Firebase, I have tried like this:
FIREBASE_REF.childByAppendingPath("tasks").observeEventType(.Value, withBlock: { (snapshot) -> Void in
print(snapshot.value)
self.tasks = [Task]()
var task = Task()
let data = snapshot.value as! NSDictionary
let tasksFromServer = data.allValues as! [NSDictionary]
for taskFromServer in tasksFromServer {
task.description = taskFromServer.objectForKey("description") as! String
task.startTime = taskFromServer.objectForKey("startTime") as! String
task.endTime = taskFromServer.objectForKey("endTime") as! String
task.progress = taskFromServer.objectForKey("progress") as! Int
let priorityTemp = taskFromServer.objectForKey("priority") as! Int
switch priorityTemp {
case 0: task.priority = .Low
case 1: task.priority = .Medium
case 2: task.priority = .High
default: break
}
task.assignee = taskFromServer.objectForKey("assignee") as! String
self.tasks.append(task)
}
MBProgressHUD.hideAllHUDsForView(self.view, animated: true)
self.tableView.reloadData()
}
but it shows error in this line:
let data = snapshot.value as! NSDictionary
It says: Could not cast value of type '__NSArrayM' (0x10ebfc8d8) to 'NSDictionary' (0x10ebfcd60).
My data from Firebase like this:
But in other side, I use another code in another ViewController to get users name and role from Firebase, it works.
FIREBASE_REF.childByAppendingPath("users").observeEventType(.Value, withBlock: { (snapshot) -> Void in
self.names = []
self.roles = []
let data = snapshot.value as! NSDictionary
let employees = data.allValues as! [NSDictionary]
for employee in employees {
let name = (employee.objectForKey("firstName") as! String) + " " + (employee.objectForKey("lastName") as! String)
self.names.append(name)
let role = employee.objectForKey("position") as! String
self.roles.append(role)
}
MBProgressHUD.hideAllHUDsForView(self.view, animated: true)
self.collectionView.reloadData()
})
But why the first code always crash.
Any helps would be appreciated. Thanks.

Firebase transforms your dictionary object to an array if more than 50% of keys are between 0 and maximum key (exactly your case with one zero element).
https://www.firebase.com/docs/ios/guide/understanding-data.html#section-arrays-in-firebase

Related

getting duplicate data while fetch messages list firebase

Hello i am creating Chat App Using Swift And Firebase i am fetching messages and populating in tableview but when i send new message then tableview dislplaying multiple entry i am useing below code for fetching messages
func fetchAllMessage(){
guard let uid = Auth.auth().currentUser?.uid else { return }
let fetchMsgGroup = Database.database().reference().child("user-messages_group_iOS").child(uid).child(self.chatID)
fetchMsgGroup.observe(.value, with: { (snapshot) in
if snapshot.exists(){
if let dictonary = snapshot.value as? [String:AnyObject]{
self.groupMessageData.removeAll()
if let userMessages = dictonary["userMessages"] as? [String:AnyObject]{
for (key, _) in userMessages{
let messagesFrtchRef = Database.database().reference().child("messages_iOS").child(key)
messagesFrtchRef.observe(.value, with: { (snapshot1) in
if snapshot1.exists(){
if let dict = snapshot1.value as? [String:AnyObject]{
let fromId = dict["fromId"] as! String
let messageUID = dict["messageUID"] as! String
let seen = dict["seen"] as! Bool
let status = dict["status"] as! String
let text = dict["text"] as! String
let timestamp = dict["timestamp"] as! Double
let told = dict["told"] as! String
let messages = GroupMessage(fromId: fromId, messageUID: messageUID, seen: seen, status: status, text: text, timestamp: timestamp, told: told)
self.groupMessageData.insert(messages, at: 0)
}
self.tblListView.reloadData()
}else{
}
}, withCancel: nil)
}
}
}
}else{
}
}, withCancel: nil)
}
i have tried everything like clearing removing also clearing observer when needed but its not work enough for me is their anyone have any solution for this then please help me
can anyone help me to solve this out

Convert observe .value to .childAdded in swift

Currently I'm having some problems with this bit of code that is loading data from firebase database into an array. Since this is inside of viewDidLoad I have to empty my array food = [] before loading the data into it, if I don't then it will duplicate all the objects and I will have double duplicates the second time it loads, triple the third time and etc... However this was not a good fix for multiple reasons so what I would like is that it would only add new objects from the database with .childAdded however if I just switch out .value with .childAdded it will crash, I get a Thread 1: signal SIGABRT on this line: let dict = user_snap.value as! [String: String?]. I am pretty new to swift and don't know how to fix this, would really appreciate some help.
let parentRef = Database.database().reference().child("Recipes")
let storage = Storage.storage()
parentRef.observe(.value, with: { snapshot in
if ( snapshot.value is NSNull ) {
// DATA WAS NOT FOUND
print("– – – Data was not found – – –")
} else {
//Clears array so that it does not load duplicates
food = []
// DATA WAS FOUND
for user_child in (snapshot.children) {
let user_snap = user_child as! DataSnapshot
let dict = user_snap.value as! [String: String?]
//Defines variables for labels
let recipeName = dict["Name"] as? String
let recipeDescription = dict["Description"] as? String
let downloadURL = dict["Image"] as? String
let storageRef = storage.reference(forURL: downloadURL!)
storageRef.getData(maxSize: 1 * 1024 * 1024) { (data, error) -> Void in
let recipeImage = UIImage(data: data!)
food.append(Element(name: recipeName!, description: recipeDescription!, image: recipeImage!))
self.tableView.reloadData()
}
}
}
})
let dict = user_snap.value as! [String: String?]
Instead of
let dict = snapshot.value as! Dictionary<String, String>
and maybe you can do null test :
let dict = snapshot.value as! Dictionary<String, String>
if let recipeName = dict["Name"] as String!, let recipeDescription = dict["Description"] as String!, let downloadURL = dict["Image"] as String! {
let storageRef = storage.reference(forURL: downloadURL)
storageRef.getData(maxSize: 1 * 1024 * 1024) { (data, error) -> Void in
let recipeImage = UIImage(data: data!)
food.append(Element(name: recipeName, description: recipeDescription, image: recipeImage!, downloadURL: downloadURL))
self.tableView.reloadData()
}
}else {
print("Error! Could not decode data")
}
try this. It should work
for child in snapshot.children.allObjects as! [FIRDataSnapshot] {
let dict = child.value as! Dictionary<String, Any>
//.....
}

Swift 3 Firebase data retrieve error: Could not cast value of type '__NSCFString' (0x1a8e00d50) to 'NSDictionary' (0x1a8e01c78)

Hey I am new with Firebase and I got problem with getting data from database, I get error on this line:
let snapshotValue = snapshot.value as! [String: AnyObject]
Could you help me with fixing this problem?
Error says:
Could not cast value of type '__NSCFString' (0x1a8e00d50) to 'NSDictionary' (0x1a8e01c78).
event controller:
init(snapshot: FIRDataSnapshot) {
key = snapshot.key
let snapshotValue = snapshot.value as! [String: AnyObject]
name = snapshotValue["name"] as! String
addedByUser = snapshotValue["addedByUser"] as! String
startTime = snapshotValue["startTime"] as! Double
endPickerTime = snapshotValue["endPickerTime"] as! Double
longtitude = snapshotValue["longtitude"] as! Double
latitude = snapshotValue["latitude"] as! Double
eventImageStringUrl = snapshotValue["eventImageStringUrl"] as! String
eventId = snapshotValue["eventId"] as! String
eventDescription = snapshotValue["eventDescription"] as! String
completed = snapshotValue["completed"] as! Bool
ref = snapshot.ref
}
Getting data from database:
override func viewDidLoad() {
super.viewDidLoad()
databaseHandle = databaseRef.child("events").observe(.childAdded, with: { (snapshot) in
var newItems: [Event] = []
for item in snapshot.children {
let event = Event(snapshot: item as! FIRDataSnapshot)
newItems.append(event)
}
})
Database scheme:
Change .childAdded to .value in .observe.

Memory leak while reloading the collectionView : Firebase

I'm trying to fill the collectionView with posts. I have to get the posts, then get some data for the users who posted them. For some reason it isn't working.
DataService.ds.REF_POSTS.child("\(self.loggedInUser!.uid)").queryLimitedToLast(30).observeSingleEventOfType(.Value, withBlock: { postDictionary in
if postDictionary.exists() {
if let snapshots = postDictionary.children.allObjects as? [FIRDataSnapshot] {
self.posts = [Post]()
for snap in snapshots {
if let postDict = snap.value as? NSDictionary {
for(name, value) in postDict {
let interval = postDict.objectForKey("timePosted") as! Double
let formattedDate = NSDate(timeIntervalSince1970: interval)
let timeAgo = self.getDate(formattedDate)
if name as! String == "postedBy" {
DataService.ds.REF_USERS.child(value as! String).observeSingleEventOfType(.Value, withBlock: { (userDictionary) in
let userDict = userDictionary.value as! NSDictionary
let username = userDict.objectForKey("username")!
let profileThumbUrl = userDict.objectForKey("profileThumbUrl")!
let key = snap.key
let post = Post(postKey: key, dictionary: postDict, username: username as! String, profileThumbUrl: profileThumbUrl as! String, timeAgo: timeAgo)
self.posts.append(post)
})
}
}
}
}
}
}
self.collectionView?.reloadData()
})
It works if I perform the reload() right after appending the posts, but there is some sort of memory leak. There isn't a problem in the Post class or filling the collection view, if I use dummy values. The problem is in this code that I posted. I think I have an extra loop or something can anyone help?
If you fear that reload() is the reason of the memory leak , you can use this hack:-
if name as! String == "postedBy" {
DataService.ds.REF_USERS.child(value as! String).observeSingleEventOfType(.Value, withBlock: { (userDictionary) in
let userDict = userDictionary.value as! NSDictionary
let username = userDict.objectForKey("username")!
let profileThumbUrl = userDict.objectForKey("profileThumbUrl")!
let key = snap.key
let post = Post(postKey: key, dictionary: postDict, username: username as! String, profileThumbUrl: profileThumbUrl as! String, timeAgo: timeAgo)
self.posts.append(post)
if posts.count == postDictionary.childrenCount{
self.collectionView?.reloadData()
}
})
}
Then also see this answer :- Firebase observeSingleEventOfType stays in memory

Ambiguous use of subscript. Array Swift IOS

I try to compile on device but i get this error. Any help?. In the simulator works perfectly.
I get an ambiguous use of subscript error in the following code and was hoping somebody else has encountered this and know the fix.
case .Success:
if response.response?.statusCode == 200 {
print ("Respuesta 200")
if let value = response.result.value {
let respuestaJSON = JSON(value)
let objsonUSUARIOS = respuestaJSON["d"].object
let arrayUsuarios = objsonUSUARIOS["results"]!
//print ("Usuarios: ",String(arrayUsuarios))
for i in 0 ..< arrayUsuarios!.count{
let boletines = boletinJSON()
if let item = arrayUsuarios![i] as? [String: AnyObject]{
)
if let person = item["Title"] as? String
{
boletines.name = person
}
if let person = item["Portada"] as? String
{
boletines.imagen = person
}
if let person = item["Created"] as? String
{
boletines.fecha = person
}
if let person = item["AttachmentFiles"] as? [String: AnyObject] {
if let itemAttach = person["__deferred"] as? [String: AnyObject]{
if let itemdeferred = itemAttach["uri"] as? String {
boletines.urldescarga = itemdeferred
}
}
}
self.boletin.append(boletines)
self.view.hideToastActivity()
}
}
}
self.tableView.reloadData()
// self.view.hideToastActivity()
}
Inform the compiler what the intermediary object objsonUSUARIOS is of type
let objsonUSUARIOS = respuestaJSON["d"].object
After the above statement, the compiler does not know what kind of object he is dealing with. So make sure that you can actually do all the casting as below
let objsonUSUARIOS = respuestaJSON["d"].object as! Dictionary
let arrayUsuarios = objsonUSUARIOS["results"]! as! Array
The problem is that you have not specified the type of object arrayUsuarios is Array, so try to explicit type cast the arrayUsuarios Array
let arrayUsuarios = objsonUSUARIOS["results"] as! [[String: AnyObject]]

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