I don't know why cant find how get friends Ids.
her is my code:
func fetchUsers() {
let ref = Firebase.Database.database().reference()
guard let userId = Auth.auth().currentUser?.uid else { return }
let userID = userId
ref.child("Users").child(userID).observe(.childAdded) { (snapshot) in
print("snapshot...\(snapshot)")
let user = User()
if let dictionary = snapshot.value as? [String:AnyObject]{
user.currentUserFriends = dictionary["Friends"] as? String
print("dictionary...\(user.currentUserFriends ?? "no value")")
}
}
}
and my tree from firebase is Users-Uid-Friends-friendID-true.
Solved!
ref.child("Users").child(userID!).child("Friends").observeSingleEvent(of: .value) { (snapshot) in
print("snapshot...\(snapshot)")
let dic = snapshot.value as! NSDictionary
for (key,value) in dic{
let friendsID = key
let friendBool = value
print("key is \(friendsID) and value is \(friendBool)")
let user = User()
user.currentUserFriends = key as? String
}
}
Related
I have stored the comments under a post in firebase realtime database. The problem i have is that when i try to parse out the data from firebase i get an error that says Unexpectedly found nil while unwrapping an Optional value. So for example if i try to pront the data stored under degree, i get this nil error. But when i print "comments" instead of the "degree" i successfully fetch the data. My database structure looks like this.
func obeserveComments() {
// get auto-id of post
let commentKey = self.keyFound
let postRef = Database.database().reference().child("posts").child(commentKey)
var tempComments = [Comments]()
postRef.observe(.value, with: {(snapshot) in
if let dict = snapshot.value as? [String:Any] {
if let comments = dict["comments"] as? [String:Any] {
let degree = comments["reply degree"] as! String
// let name = comments["reply name"] as! String
// let text = comments["reply text"] as! String
// let university = comments["reply university"] as! String
// let photoURL = comments["reply url"] as! String
// let url = URL(string: photoURL)
// let timestamp = comments["timestamp"] as! Double
print(degree)
}
}
})
}
The answer by #aytroncb is a good answer, I prefer to leave Firebase data 'Firebasy' as long as possible. In other words coverting to dictionaries looses ordering and and find code like this
[String: [String: [String: Any]]]
To be very hard to read.
I prefer
let snap = snapshot.childSnapshot("comments") //snap becomes a DataSnapshot
So my solution maintains the order and leverages .childSnapshot to leave data in it's DataSnapshot form.
func readPostComments() {
let postRef = self.ref.child("posts") //self.ref points to my firebase
postRef.observeSingleEvent(of: .value, with: { snapshot in
let allPosts = snapshot.children.allObjects as! [DataSnapshot]
for postSnap in allPosts {
print("postId: \(postSnap.key)")
let commentsSnap = postSnap.childSnapshot(forPath: "comments") //will be a DataSnapshot
let allComments = commentsSnap.children.allObjects as! [DataSnapshot]
for commentSnap in allComments {
print(" commentId: \(commentSnap.key)")
let replyDegree = commentSnap.childSnapshot(forPath: "reply_degree").value as? String ?? "No Degree"
let replyName = commentSnap.childSnapshot(forPath: "reply_name").value as? String ?? "No Name"
print(" degree: \(replyDegree) by: \(replyName)")
}
}
})
}
EDIT
For a single post, remove the top part of the code that reads in and iterates over all posts.
func readCommentsForOnePost() {
let postRef = self.ref.child("posts")
let postCommentRef = postRef.child("post_0")
postCommentRef.observeSingleEvent(of: .value, with: { snapshot in
print("postId: \(snapshot.key)")
let commentsSnap = snapshot.childSnapshot(forPath: "comments") //will be a DataSnapshot
let allComments = commentsSnap.children.allObjects as! [DataSnapshot]
for commentSnap in allComments {
print(" commentId: \(commentSnap.key)")
let replyDegree = commentSnap.childSnapshot(forPath: "reply_degree").value as? String ?? "No Degree"
let replyName = commentSnap.childSnapshot(forPath: "reply_name").value as? String ?? "No Name"
print(" degree: \(replyDegree) by: \(replyName)")
}
})
}
Its because firebase is returning your data like this
{
"MAKFW244kdL)Cw;1": [Array of data],
"LOPSw!35pa3flAL4": [Array of data],
"ALV34VR4_A6Vn1a": [Array of data]
}
So change your initial casting of snapshot.value to this:
if let dict = snapshot.value as? [String: [String: Any]]
then loop through that new dictionary like this:
for objectJson in dict.values {
if let comments = objectJson["comments"] as? [String: [String: Any]] {
for commentJson in comments.values {
let degree = commentJson["reply_degree"] as? String
}
}
}
Update
Just read through your post again and noticed your trying to access the comments directly with a key, your first going to need to provide the PostId. Then you can use the above code to loop through the objects
let postRef = Database.database().reference().child("posts").child(postID)
alternatively I believe you can have the comments returned as a normal list by doing something like this:
let postRef = Database.database().reference().child("posts").child("\(postID)/{id}")
I've been trying to filter data by a string array within firebase to return only the filtered values but the app crashes when I try to run the function. Is this the way it should be done? (The function isn't called if the array is empty)
func fetchFilteredActivities() {
let ref = Database.database().reference().child("posts").queryOrdered(byChild: "category").queryEqual(toValue: filterList)
ref.observe(.childAdded) { (snapshot) in
guard let dictionary = snapshot.value as? [String: Any] else { return }
guard let uid = dictionary["uid"] as? String else { return }
guard let latitudeString = dictionary["latitude"] as? String else { return }
guard let longitudeString = dictionary["longitude"] as? String else { return }
let latitude = (latitudeString as NSString).doubleValue
let longitude = (longitudeString as NSString).doubleValue
Database.fetchUserWithUID(uid: uid, completion: { (user) in
guard let dictionary = snapshot.value as? [String: Any] else { return }
var post = Post(postId: snapshot.key, user: user, dictionary: dictionary)
let postId = snapshot.key
post.id = snapshot.key
let coords = [CLLocation(latitude: latitude, longitude: longitude)]
self.addAnnotation(post: post, title: post.category, subtitle: nil, coords: coords)
})
}
}
The error:
libc++abi.dylib: terminating with uncaught exception of type NSException
I am trying to retrieve a list of posts from my firebase database, but it is not working. The specific piece of code that I am having trouble with is the line ref.child("users").queryOrderedByKey().observeSingleEvent. When I debug the application, it just skips over this line and the app jumps to ref.removeAllObservers(). Am I calling the correct functions to retrieve from my database? The tutorial I am using is from Swift3 so it may be outdated.
I have tried calling observe instead of observeSingleEvent, but that had the same outcome.
Here is my fetchPosts function:
func fetchPosts(){
let ref = Database.database().reference()
ref.child("users").queryOrderedByKey().observeSingleEvent(of: .value, with: {snapshot in
let users = snapshot.value as! [String : AnyObject]
for (_,value) in users {
if let uid = value["uid"] as? String{
if uid == Auth.auth().currentUser?.uid {
if let followingUsers = value["following"] as? [String: String]{
for(_, user) in followingUsers {
self.following.append(user)
}
}
self.following.append(Auth.auth().currentUser!.uid)
ref.child("posts").queryOrderedByKey().observeSingleEvent(of: .value, with: {(snap) in
let postsSnap = snap.value as! [String : AnyObject]
for(_, post) in postsSnap {
if let userID = post["userID"] as? String{
for each in self.following{
if each == userID{
let posst = Post()
if let author = post["author"] as? String, let likes = post["likes"] as? Int, let pathToImage = post["pathToImage"] as? String, let postID = post["postID"] as? String{
posst.author = author
posst.likes = likes
posst.pathToImage = pathToImage
posst.postID = postID
posst.userID = userID
self.posts.append(posst)
}
}
}
self.collectionview.reloadData()
}
}
})
}
}
}
})
ref.removeAllObservers()
}
I hope to fill a collection view with post information from my Firebase database. There are no error messages.
Hi there i'm newest in swift. I am working with a firebase database with at 2 layer of hierarchy as well as many children for each node. I got 1st layer (descript, enddata and other), but i stll can't get the news node. Is in 3 to 5 random keys. I sow many issues but still not have issue for me.
I'm understand i'm doing some wrong but what?
The Firebase is:
i need retreat the news child
struct is
struct ICONews {
let ICOId: String
let news1: String
let news2: String
let news3: String
init?(ICOId: String, dict: [String: Any] ) {
self.ICOId=ICOId
guard let news1 = dict[""] as? String,
let news2 = dict[""] as? String,
let news3 = dict[""] as? String
else { return nil }
self.news1 = news1
self.news2 = news2
self.news3 = news3
}
}
struct NewsSnapShot {
let posts: [ICONews]
init?(with snapshot: DataSnapshot) {
var posts = [ICONews] ()
guard let snapDict = snapshot.value as? [String: [String: Any]] else { return nil }
for snap in snapDict {
guard let post = ICONews (ICOId: snap.key, dict: snap.value) else {continue}
posts.append(post)
}
self.posts=posts
}
}
class of DataBase
class DatabaseService {
static let shared = DatabaseService()
private init(){}
let ICOReference = Database.database().reference()
}
and retreat method
DatabaseService.shared.ICOReference.child("news").observe(DataEventType.value, with: { (snapshot) in
guard let postsSnapShot = ICOSnapShot(with: snapshot) else {return}
})
done
Database.database().reference().observeSingleEvent(of: .value, with: {(snapshot) in
let enumerator = snapshot.children
while let rest = enumerator.nextObject() as? DataSnapshot {
let values = (rest as! DataSnapshot).value as? NSDictionary
let enumeratorMap1 = (rest as! DataSnapshot).children
while let rest2 = enumeratorMap1.nextObject() as? DataSnapshot {
let valuesMap1 = (rest2 as! DataSnapshot).value as? NSDictionary
if (rest2 as! DataSnapshot).key == "news" {
print(rest2.value)
}
}
}
})
Make the the Firebase Api call like
Database.database().reference().child("users").child(userID).observe(.childAdded, with: { (snapshot) in
if snapshot.exists() {
let receivedMessage = snapshot.value as! [String: Any]
let name = receivedMessage["name"] as? String ?? ""
let id = receivedMessage["id"] as? Double ?? 0.0
let profileurl = receivedMessage["url"] as? String ?? ""
completion(User(name: name, id: id, url: url))
} else {
failure()
}
})
This is my realtime database structure. I have only 1 item in club. In reality, I have many items.
I want to read all clubs information, and try to get the related address using club's key.
here is my code:
func loadClubs() {
ref = Database.database().reference()
let clubRef = ref.child("club")
let refHandle = clubRef.observe(DataEventType.value, with: { (snapshot) in
if let c = snapshot.value as? [String : AnyObject] {
let name = c["name"] as! String // PRINT NIL
}
// ...
})
}
How can I retrieve a club's name, courtNum, explanation,...?
try this:-
ref = Database.database().reference()
ref.child("club").observe(.value, with: { (snapshot) in
print("clubs: \(snapshot)")
if(snapshot.exists()) {
let array:NSArray = snapshot.children.allObjects as NSArray
for obj in array {
let snapshot:FIRDataSnapshot = obj as! FIRDataSnapshot
if let childSnapshot = snapshot.value as? [String : AnyObject]
{
if let clubName = childSnapshot["name"] as? String {
print(clubName)
}
}
}
}
}