I would like to get some data in user profile, I've got some info but I got stuck at this one.
Firebase database:
Here is some of my code:
self.ref.child("users").child("profile").observe(.childAdded, with: { (snapshot) in
if let dictionary = snapshot.value as? [String:Any] {
let user = User()
let brands = dictionary["status"] as! NSDictionary
user.displayname = dictionary["displayname"] as? String
user.isconnected = brands["isconnected"] as? String
print(user.isconnected) //fatal error: unexpectedly found nil while unwrapping an Optional value
class User: NSObject {
var displayname: String?
var isconnected: String?
}
Try something like that :
guard let dictionary = snapshot.value as? [String: Any] else {
return
}
guard let statusDictionary = dictionary["status"] as? [String: Any] else {
return
}
guard let deviceStatusDictionary = statusDictionary["DEVICE_KEY"] as? [String: Any] else {
return
}
let user = User()
user.displayname = dictionary["displayname"] as? String
user.isconnected = deviceStatusDictionary["isconnected"] as? Bool
You need to know your device key.
And :
class User: NSObject {
var displayname: String?
var isconnected: Bool?
}
Related
I am manually entering in data into my database and the only variable not getting passed from my database is the author and I do not know where I am going wrong.
func getAllArticles(handler: #escaping (_ articles: [Article])-> ()){
var articleArray = [Article]()
REF_ARTICLES.observeSingleEvent(of: .value) { (articleMessageSnapshot) in
guard let articleMessageSnapshot = articleMessageSnapshot.children.allObjects as? [DataSnapshot] else {return}
for article in articleMessageSnapshot {
let content = article.childSnapshot(forPath: "content").value as? String ?? "no content"
let author = article.childSnapshot(forPath: "author").value as? String ?? "no author"
let twitterHandle = article.childSnapshot(forPath: "twitterHandle").value as? String ?? "none"
let articleTitle = article.childSnapshot(forPath: "articleTitle").value as? String ?? "no title"
let date = article.childSnapshot(forPath: "date").value as? String ?? "no date"
let article = Article(content: content, author: author, twitterHandle: twitterHandle, ArticleTitle: articleTitle, date: date)
articleArray.append(article)
}
handler(articleArray)
}
}
Please check out below code
var articleArray = [Article]()
//REF_ARTICLES
let ref = Database.database().reference().child(“articles”)
ref.observe(.childAdded, with: { (snapshot) in
print(snapshot)
guard let dictionary = snapshot.value as? [String : AnyObject] else {
return
}
let articleObj = Article()
articleObj.Content = dictionary["content"] as? String
articleObj.Author = dictionary["author"] as? String
articleObj.Twitterhandle = dictionary["twitterHandle"] as? String
articleObj.Title = dictionary["articleTitle"] as? String
articleObj.Date = dictionary["date"] as? String
self. articleArray.append(articleObj)
}, withCancel: nil)
}
I am also working on similar app where i am storing data to firebase and retrieving. Below approach i used to fetch the data from firebase database. Please try once.
func getAllArticles(handler: #escaping (_ articles: [Article])-> ()) {
Database.database().reference().child("Articles").observe(.childAdded, with: { (snapshot) in
print("articles = \(snapshot)")
if let dict = snapshot.value as? [String: Any] {
let article = Article()
article.articleTitle = dict["articleTitle"] as? String
article.author = dict["author"] as? String
article.twitterHandle = dict["twitterHandle"] as? String
article.date = dict["date"] as? String
article.content = dict["content"] as? String
self.articleArray.append(article)
}
handler(articleArray)
}, withCancel: nil)
}
im not sure what the underlying issue was, but i fixed it by deleting "author" from the firebase tree and then adding it back
I have this function that is grabbing events from firebase that a specific user is attending. Everything seems to be working up until the point where I try to alter an element relative to the event snapshot.
I get the error
Cannot assign to property: 'event' is a 'let' constant
//will show the vents that a user is attending
static func Events(for user: User, completion: #escaping ([Event]) -> Void)
{
var currentEvents = [Event]()
//Getting firebase root directory
let ref = Database.database().reference().child("users").child(user.uid).child("Attending")
ref.observe(.value, with: { (snapshot) in
// print(snapshot)
// guard snapshot.children.allObjects is [DataSnapshot] else {
// return completion([])
// }
guard let eventDictionary = snapshot.value as? [String: Any] else {
return completion([])
}
// print(snapshot)
let dispatchGroup = DispatchGroup()
eventDictionary.forEach({ (key,value) in
// print(key)
// print(value)
EventService.show(forEventKey: key , completion: { (event) in
dispatchGroup.enter()
AttendService.isEventAttended(event, byCurrentUserWithCompletion: { (isAttended) in
//error happens here
event?.isAttending = isAttended
dispatchGroup.leave()
})
currentEvents.append(.init(currentEventKey: key , dictionary: (event?.eventDictionary)!))
completion(currentEvents)
})
})
})
}
It is really confusing to me because I can't see where I declared it as a let constant.
This is the code for the method I am using to gather event info
static func show(forEventKey eventKey: String, completion: #escaping (Event?) -> Void) {
// print(eventKey)
let ref = Database.database().reference().child("events").child(eventKey)
// print(eventKey)
//pull everything
ref.observeSingleEvent(of: .value, andPreviousSiblingKeyWith: { (snapshot,eventKey) in
// print(snapshot.value ?? "")
guard let event = Event(snapshot: snapshot) else {
return completion(nil)
}
completion(event)
})
}
Below is my model for an event object
import Foundation
import FirebaseDatabase.FIRDataSnapshot
struct Event: Keyed {
var key: String?
let currentEventName: String
let currentEventImage: String
let currentEventPromo: String?
let currentEventDescription: String
//nested properties
let currentEventStreetAddress: String
let currentEventCity: String
let currentEventState: String
let currentEventDate: String?
let currentEventTime: String?
let currentEventEndTime: String?
let currentEventZip: Int
var category: String
//nested properties stop
var currentAttendCount: Int
var isAttending = false
var eventDictionary: [String: Any]{
let dateDict = ["start:date":currentEventDate, "start:time": currentEventTime,"end:time":currentEventEndTime]
return ["event:name":currentEventName,"event:imageURL" : currentEventImage,
"event:description": currentEventDescription, "attend:count": currentAttendCount,
"event:street:address": currentEventStreetAddress,"event:zip": currentEventZip,
"event:state": currentEventState, "event:city": currentEventCity, "event:promo": currentEventPromo ?? "", "event:date": dateDict, "event:category":category]
}
init(currentEventKey: String, dictionary: [String:Any]) {
self.key = currentEventKey
self.currentEventName = dictionary["event:name"] as? String ?? ""
self.currentEventImage = dictionary["event:imageURL"] as? String ?? ""
self.currentEventDescription = dictionary["event:description"] as? String ?? ""
self.currentEventPromo = dictionary["event:promo"] as? String ?? ""
self.currentAttendCount = dictionary["attend:count"] as? Int ?? 0
self.category = dictionary["event:category"] as? String ?? ""
//nested properties
self.currentEventStreetAddress = dictionary["event:street:address"] as? String ?? ""
self.currentEventCity = dictionary["event:city"] as? String ?? ""
self.currentEventState = dictionary["event:state"] as? String ?? ""
self.currentEventZip = dictionary["event:zip"] as? Int ?? 0
let eventDate = dictionary["event:date"] as? [String: Any]
self.currentEventDate = eventDate?["start:date"] as? String ?? ""
self.currentEventTime = eventDate?["start:time"] as? String ?? ""
self.currentEventEndTime = eventDate?["end:time"] as? String ?? ""
}
init?(snapshot: DataSnapshot) {
guard let dict = snapshot.value as? [String : Any],
let currentEventName = dict["event:name"] as? String,
let currentEventImage = dict["event:imageURL"] as? String,
let currentEventDescription = dict["event:description"] as? String,
let currentEventPromo = dict["event:promo"] as? String,
let category = dict["event:category"] as? String,
let currentEventStreetAddress = dict["event:street:address"] as? String,
let currentEventCity = dict["event:city"] as? String,
let currentEventState = dict["event:state"] as? String,
let currentEventZip = dict["event:zip"] as? Int,
let currentAttendCount = dict["attend:count"] as? Int,
let eventDate = dict["event:date"] as? [String: Any],
let currentEventDate = eventDate["start:date"] as? String,
let currentEventTime = eventDate["start:time"] as? String,
let currentEventEndTime = eventDate["end:time"] as? String
else { return nil }
self.key = snapshot.key
self.currentEventName = currentEventName
self.currentEventImage = currentEventImage
self.currentEventDescription = currentEventDescription
self.currentEventStreetAddress = currentEventStreetAddress
self.currentEventCity = currentEventCity
self.currentEventState = currentEventState
self.currentEventZip = currentEventZip
self.currentAttendCount = currentAttendCount
self.currentEventPromo = currentEventPromo
self.currentEventDate = currentEventDate
self.currentEventTime = currentEventTime
self.currentEventEndTime = currentEventEndTime
self.category = category
}
}
Event is a struct, so its instances are passed by value. That is, the call completion(event) passes a copy of event to completion.
Since completion doesn't take the Event as an inout, it is treated as a let, not a var, so you cannot modify it.
You could change the type of completion to #escaping (inout Event?) -> Void. Then the Event will be treated as a var, and changes to it will be effectively copied back out to the caller.
However, that won't make a difference in your case, because you're creating a brand new Event instance for the call to completion (by saying guard let event = Event(snapshot: snapshot)). So even if you let completion modify the Event it receives, you just throw it away after. You also need to write it back to your database somehow after completion returns, if you want the change to isAttending to have any effect.
I'm comfortable with initializing objects in general but my method only seems to work when all parameters must exist on the database. I have looked at this which works. But I now don't know how to initialize it with a nest array.
This is how I would normally initialise an object:
class User {
var firstName: String
var lastName: String
var summary: String?
var groups = [Group]()
var ref: DatabaseReference?
var key: String
init?(from snapshot: DataSnapshot) {
let snapshotValue = snapshot.value as? [String: Any]
guard let firstName = snapshotValue?["firstName"] as? String, let lastName = snapshotValue?["lastName"] as? String, let summary = snapshotValue?["summary"] as? String else { return nil }
self.firstName = firstName
self.lastName = lastName
self.summary = summary
self.key = snapshot.key
self.groups(snapshot: snapshot.childSnapshot(forPath: "groups"))
}
func groups(snapshot: DataSnapshot) {
for child in snapshot.children {
guard let group = child as? DataSnapshot else { continue }
}
}
Just don't make the optional properties a part of that guard (that's what prevents the execution to finish it:
init?(from snapshot: DataSnapshot) {
let snapshotValue = snapshot.value as? [String: Any]
guard let firstName = snapshotValue?["firstName"] as? String,
let lastName = snapshotValue?["lastName"] as? String else { return nil }
self.firstName = firstName
self.summary = snapshotValue?["summary"] as? String
self.key = snapshot.key
self.groups(snapshot: snapshot.childSnapshot(forPath: "groups"))
}
Optionally, you can use if let syntax:
if let summary = snapshotValue?["summary"] as? String {
self.summary = summary
}
But in this case this is simpler:
self.summary = snapshotValue?["summary"] as? String
Here I tried to parse the data from my local server but unable to parse it and it returning empty data and below are my model classes from which the data I was passing to an table view which can anyone help me what's wrong in implementing it?
Here I had attached my image which follows the Json format:
Code:
var homePageModel = [HomeBanner]()
func HomeBannerDownloadJsonWithURL(){
let url = URL(string: homePageUrl)!
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
if error != nil { print(error!); return }
do {
if let jsonObj = try JSONSerialization.jsonObject(with: data!) as? [[String:Any]] {
for item in jsonObj {
print(item)
for dict in item {
print(dict)
let dict = HomeBanner(json: item)
self.homePageModel.append(dict!)
print(self.homePageModel)
}
}
print(self.homePageModel)
DispatchQueue.main.async {
self.homeTableView.delegate = self
self.homeTableView.dataSource = self
self.homeTableView.reloadData()
}
}
} catch {
print(error)
}
}
task.resume()
}
struct HomeBanner {
let title : String?
let titleInArabic : String?
let showTitle : String?
var banner = [ChildrenBanners]()
init?(json : [String:Any]) {
if let customAttribute = json["childran_banners"] as? [[String: AnyObject]] {
var result = [ChildrenBanners]()
for obj in customAttribute {
result.append(ChildrenBanners(json: obj as! [String : String])!)
}
self.banner = result
} else {
self.banner = [ChildrenBanners]()
}
self.title = json["title"] as? String ?? ""
print(self.title)
self.titleInArabic = json["title_in_arabic"] as? String ?? ""
self.showTitle = json["show_title"] as? String ?? ""
}
}
struct ChildrenBanners {
let bannerId : String?
let name : String?
let status : String?
let sliderId : String?
let desktopImage : String?
let mobileImage : String?
let imageAlt : String?
let sortOrder : String?
let startTime : String?
let endTime : String?
init?(json : [String:Any]) {
self.bannerId = json["banner_id"] as? String ?? ""
print(self.bannerId)
self.name = json["name"] as? String ?? ""
self.status = json["status"] as? String ?? ""
self.sliderId = json["slider_id"] as? String ?? ""
self.desktopImage = json["desktop_image"] as? String ?? ""
self.mobileImage = json["mobile_image"] as? String ?? ""
self.imageAlt = json["image_alt"] as? String ?? ""
self.sortOrder = json["sort_order"] as? String ?? ""
self.startTime = json["start_time"] as? String ?? ""
self.endTime = json["end_time"] as? String ?? ""
}
}
Just try these lines of code
if let jsonObj = try JSONSerialization.jsonObject(with: data!) as? [[String:Any]] {
self.homePageModel = jsonObj.map{HomeBanner(json: $0)}
print(self.homePageModel)
DispatchQueue.main.async {
self.homeTableView.delegate = self
self.homeTableView.dataSource = self
self.homeTableView.reloadData()
}
}
} catch {
print(error)
}
and there is no necessity of making optional initializer for HomeBanner and ChildrenBanners just use init(json : [String : Any]){} for both struct
Root of json is an array and then second level is dictionary with keys list1, list2 etc. You are missing that in your code. Should be something like this (I haven't compiled it).
if let data = data, let jsonObj = try JSONSerialization.jsonObject(with: data) as? [[String:[String:Any]]] {
for item in jsonObj {
for (_, dict) in item {
if let obj = HomeBanner(json: dict) {
self.homePageModel.append(obj)
}
}
}
}
There are lot of other issues in your code. Like force unwrapping optional. Using same parameters again within a scope. For example.
for dict in item {
let dict = HomeBanner(json: item)
// ....
}
You shouldn't use same param names like you are using dict it hides the scope of the outer dict.
I'm trying to make a fetch from my database to populate a collection view, in order of newest at the top, down to oldest. I tried using snap.children.allObjects.reversed(), but my app crashes upon loading. Here's the full fetch function:
func fetchPosts() {
let ref = FIRDatabase.database().reference()
ref.child("users").queryOrderedByKey().observe(.value, with: { snapshot in
let users = snapshot.value as! [String : AnyObject]
for (_, value) in users {
if let uid = value["uid"] as? String {
if uid == FIRAuth.auth()?.currentUser?.uid {
if let followingUsers = value["following"] as? [String : String] {
for (_, user) in followingUsers {
self.following.append(user)
}
}
self.following.append(FIRAuth.auth()!.currentUser!.uid)
ref.child("posts").queryOrderedByKey().observeSingleEvent(of: .value, with: { (snap) in
for postSnapshot in snap.children.allObjects.reversed() as! [FIRDataSnapshot] {
let value = postSnapshot.value as! [String : AnyObject]
if let userID = value["userID"] as? String {
for each in self.following {
if each == userID {
let posst = Post()
if let poster = value["poster"] as? String, let likes = value["likes"] as? Int, let pathToImage = value["pathToImage"] as? String, let postID = value["postID"] as? String {
posst.poster = poster
posst.likes = likes
posst.pathToImage = pathToImage
posst.postID = postID
posst.userID = userID
if let people = value["peopleWhoLike"] as? [String : AnyObject] {
for (_, person) in people {
posst.peopleWhoLike.append(person as! String)
}
}
posts.append(posst)
}
}
}
self.collectionView.reloadData()
}
}
})
ref.removeAllObservers()
}
}
}
})
}
The error is EXC_BAD_INSTRUCTION (code=EXC_1386_INVOP, subcode=0x0), with the warning Cast from 'ReversedRandomAccessCollection<[Any]>' (aka 'ReversedRandomAccessCollection>') to unrelated type '[FIRDataSnapshot]' always fails.
Is .reversed not the way to go about this? As it is, my code without .reversed loads the posts in order from oldest at the top, down to the newest at the bottom. How can I switch it around?
EDIT: Firebase snippet of posts:
"posts" : {
"-KfWzWv8rP38bUreDupj" : {
"likes" : 1,
"pathToImage" : "https://firebasestorage.googleapis.com/v0/b/cloudcamerattt.appspot.com/o/posts%2F1JSgke8QqFds4CxF2Z4MhuzbRoW2%2F-KfWzWv8rP38bUreDupj.jpg?alt=media&token=fef86bea-1ae2-4e1e-82fa-6209bc281a5e",
"peopleWhoLike" : {
"-KfX29jTcwaQDpkdIVX8" : "yI6NokUl2mTa7Uah4SgtAiulTJH2",
"-KfXQJBRemZUCI2ieT94" : "MpnGvQj7ZOdz12zKD0bTeX1kp0B3"
},
"postID" : "-KfWzWv8rP38bUreDupj",
"poster" : "Harry Potter",
"userID" : "1JSgke8QqFds4CxF2Z4MhuzbRoW2"
},
EDIT 2: Adding a timestamp
Added var timestamp: Int! to my Post object, then add it into my upload function:
func uploadToFirebase() {
AppDelegate.instance().showActivityIndicator()
let uid = FIRAuth.auth()!.currentUser!.uid
let ref = FIRDatabase.database().reference()
let storage = FIRStorage.storage().reference(forURL: "gs://cloudcamerattt.appspot.com")
let key = ref.child("posts").childByAutoId().key
let imageRef = storage.child("posts").child(uid).child("\(key).jpg")
let data = UIImageJPEGRepresentation(self.previewImage.image!, 0.6)
var Timestamp: TimeInterval {
return NSDate().timeIntervalSince1970 * 1000
}
let uploadTask = imageRef.put(data!, metadata: nil) { (metadata, error) in
if error != nil {
print(error!.localizedDescription)
AppDelegate.instance().dismissActivityIndicator()
return
}
imageRef.downloadURL(completion: { (url, error) in
if let url = url {
let feed = ["userID" : uid,
"pathToImage" : url.absoluteString,
"likes" : 0,
"poster" : FIRAuth.auth()!.currentUser!.displayName!,
"postID" : key,
"timestamp" : (0-Timestamp)] as [String : Any]
let postFeed = ["\(key)" : feed]
ref.child("posts").updateChildValues(postFeed)
AppDelegate.instance().dismissActivityIndicator()
let feedController = self.storyboard?.instantiateViewController(withIdentifier: "feedVC") as! FeedViewController
feedController.navigationItem.setHidesBackButton(true, animated: false)
self.tabBarController?.selectedIndex = 0
}
})
}
uploadTask.resume()
}
Then add it into my fetch:
let posst = Post()
if let poster = value["poster"] as? String, let likes = value["likes"] as? Int, let pathToImage = value["pathToImage"] as? String, let postID = value["postID"] as? String, let timestamp = value["timestamp"] as? Int {
posst.poster = poster
posst.likes = likes
posst.pathToImage = pathToImage
posst.postID = postID
posst.userID = userID
posst.timestamp = timestamp
Updated fetch function (results in crash Could not cast value of type 'FIRDataSnapshot' (0x10584eee8) to 'NSArray' (0x107b43dd8).):
func fetchPosts() {
let ref = FIRDatabase.database().reference()
ref.child("users").queryOrderedByKey().observe(.value, with: { snapshot in
let users = snapshot.value as! [String : AnyObject]
for (_, value) in users {
if let uid = value["uid"] as? String {
if uid == FIRAuth.auth()?.currentUser?.uid {
if let followingUsers = value["following"] as? [String : String] {
for (_, user) in followingUsers {
self.following.append(user)
}
}
self.following.append(FIRAuth.auth()!.currentUser!.uid)
for child in snapshot.children.reversed() {
let snap = child as! [FIRDataSnapshot]
ref.child("posts").queryOrdered(byChild: "timestamp").observeSingleEvent(of: .value, with: { (snap) in
if let userID = value["userID"] as? String {
for each in self.following {
if each == userID {
let posst = Post()
if let poster = value["poster"] as? String, let likes = value["likes"] as? Int, let pathToImage = value["pathToImage"] as? String, let postID = value["postID"] as? String, let timestamp = value["timestamp"] as? Int {
posst.poster = poster
posst.likes = likes
posst.pathToImage = pathToImage
posst.postID = postID
posst.userID = userID
posst.timestamp = timestamp
if let people = value["peopleWhoLike"] as? [String : AnyObject] {
for (_, person) in people {
posst.peopleWhoLike.append(person as! String)
}
}
posts.append(posst)
}
}
}
self.collectionView.reloadData()
}
})
}
ref.removeAllObservers()
}
}
}
})
}
Try
for child in snapshot.children.reversed() {
let snap = child as! FIRDataSnapshot
print(snap)
}
You are ordering by key which will load the oldest to the newest. If you want to reverse the order, and let Firebase do the heavy lifting, use a technique for reverse chronological order posted here
In Firebase, how can I query the most recent 10 child nodes?
Then it's easy to do a reverse query...
"posts" : {
"-KfWzWv8rP38bUreDupj" : {
"likes" : 1,
"pathToImage" : "https:/...",
"peopleWhoLike" : {
"-KfX29jTcwaQDpkdIVX8" : "yI6NokUl2mTa7Uah4SgtAiulTJH2",
"-KfXQJBRemZUCI2ieT94" : "MpnGvQj7ZOdz12zKD0bTeX1kp0B3"
},
"postID" : "-KfWzWv8rP38bUreDupj",
"poster" : "Harry Potter",
"timestamp" : -1.46081635550362E12, //Just add this child
"userID" : "1JSgke8QqFds4CxF2Z4MhuzbRoW2"
},
and then
ref.child("posts").queryOrdered(byChild: "timestamp").observe(...
Also, the duplicate postID is probably not needed as a child as it's the key to the post as well.
You are correct that you need to cast something somewhere, because Swift only knows that we started with an array of Any. The problem is that you are casting the wrong thing in the wrong place. Cast postSnapshot at the start of the inside of the for loop.
The way to figure out this sort of thing is to make a simplified playground example. You are doing the equivalent of this:
let arr : [Any] = [1,2,3]
for i in arr.reversed() as! [Int] { // crash
}
What we know in that example, however, is not something about arr.reversed(); it is that i is an Int. This is fine:
let arr : [Any] = [1,2,3]
for i in arr.reversed() {
if let i = i as? Int {
// now it is safe to use `i`
}
}
Your case is parallel. At the start of the for loop, you need to cast postSnapshot to a FIRDataSnapshot. Now you can proceed.