I want to be able to list users in a tableview by fetching their UID Value from a key stored in my database. As of now, the code only fetches the first value in the database rather than all of the values. Here is the code for fetching the applicants.
func loadApplicants() {
let usersRef = ref.child("users")
usersRef.observe(.value, with: { (users) in
var resultArray = [UserClass]()
for user in users.children {
let user = UserClass(snapshot: user as! DataSnapshot)
if user.uid == self.job.userID {
let appRef = self.ref.child("jobs").child(self.job.postID).child("applicants")
appRef.queryOrderedByKey().observeSingleEvent(of: .childAdded, with: { (snapshot) in
let sValue = snapshot.value
resultArray.append(user)
})
}
}
}) { (error) in
print(error.localizedDescription)
}
}
This is what my database looks like where the User's UIDs are stored.
jobs
"Job ID"
applicants:
-KtLJaQnFMnyI-MDWpys:"8R6ZAojX0FNO7aSd2mm5aQXQFpk1"
-KtLLBFU_aVS_xfSpw1k:"GGqjtYvwSwQw9hQCVpF4lHN0kMI3"
If I was to run the app, it fetches UID: "8R6ZAojX0FNO7aSd2mm5aQXQFpk1"
How can I implement a for loop or an if statement to ensure that all of the values are taken and appended into the table view
I know that I need a for loop before the fetchApplicants is called from AuthService because it is only fetching one UID but I can't work out where it would go.
Thanks.
P.S. This is what I have tried
func loadApplicants() {
let jobID = job.postID
let appRef = ref.child("jobs").child(jobID!).child("applicants")
appRef.queryOrderedByKey().observeSingleEvent(of: .childAdded, with: { (snapshot) in
if let applicants = snapshot.value! as? [String:AnyObject] {
for (value) in applicants {
self.authService.fetchApplicants(applicantID: "\(value!)", completion: { (users) in
self.usersArray = users
self.tableView.reloadData()
})
}
}
})
}
but the output is:
(key: "-KtLLBFU_aVS_xfSpw1k", value: GGqjtYvwSwQw9hQCVpF4lHN0kMI3)
(key: "-KtLJaQnFMnyI-MDWpys", value: 8R6ZAojX0FNO7aSd2mm5aQXQFpk1)
Needed to use observe instead of observeSingleEvent
Answer:
appRef.queryOrderedByKey().observe(.childAdded, with: { (snapshot) in
Related
Current user in App tap the Like button on post (audio record) from another user and it appears in likes branch in Firebase. There is another branch records, where all records from each users exist.
I've got a Firebase structure
Blue: current userID,
Green: another userID,
Red: recordID.
I need to display on my ViewController only liked records (red line), but with my code I've got all records from another user (green line). How to display only liked records (red line)?
fileprivate func fetchRecordsWithUser(user: User2){
let ref = Database.database().reference().child("records").child(user.uid)
ref.observeSingleEvent(of: .value, with: { (snapshot) in
guard let dictionaries = snapshot.value as? [String: Any] else { return }
dictionaries.forEach({ (key, value) in
guard let dictionary = value as? [String: Any] else { return }
let record = Records(user: user, dictionary: dictionary)
self.records.append(record)
self.records.sort(by: { (p1, p2) -> Bool in
return p1.creationDate.compare(p2.creationDate) == .orderedDescending
})
self.tableView?.reloadData()
})
}) { (err) in
print ("Faild to fetch records:", err)
}
}
I am a little unclear on the question but let me give this a try
Lets's start with a structure like in the question, using simpler data.
likes
uid_0
uid_1
record_0: true
uid_2
record_1: true
uid_1
uid_0
record_3: true
I believe the object is the get the values record_0, record_1 and record_3 so the code to do that is:
func printRecordIds() {
var recordIdArray = [String]()
let likesRef = self.ref.child("likes")
likesRef.observeSingleEvent(of: .value, with: { snapshot in
let allLikes = snapshot.children.allObjects as! [DataSnapshot]
for likeSnap in allLikes {
let uid = likeSnap.key
print(uid)
let uidLikes = likeSnap.children.allObjects as! [DataSnapshot]
for childLike in uidLikes {
let childUid = childLike.key
print(" child uid: \(childUid)")
let childRecords = childLike.children.allObjects as! [DataSnapshot]
for child in childRecords {
let recordId = child.key
print(" recordId: \(recordId)")
recordIdArray.append(recordId)
}
}
for r in recordIdArray {
print(r)
}
}
})
and the output
uid_0
child uid: uid_1
recordId: record_0
child uid: uid_2
recordId: record_1
record_0
record_1
uid_1
child uid: uid_0
recordId: record_3
record_0
record_1
record_3
So the output shows the data we are reading in per node so you can see the flow and then the array, populated with the record id's.
I'm trying to paginate posts that users are following to my collection view from my firebase database. Currently only 4 posts are being appended to the collection view and not loading anymore when I scroll down.
I've tried changing the number of posts loaded initially with no luck.
fileprivate func fetchFollowingUserIds() {
guard let uid = Auth.auth().currentUser?.uid else { return }
Database.database().reference().child("user-following").child(uid).observeSingleEvent(of: .value, with: { (snapshot) in
guard let userIdsDictionary = snapshot.value as? [String: Any] else { return }
userIdsDictionary.forEach({ (key, value) in
Database.fetchUserWithUID(uid: key, completion: { (user) in
self.fetchPostsWithUser(user: user)
})
})
}) { (err) in
print("Failed to fetch following user ids:", err)
}
}
var posts = [Post]()
fileprivate func fetchPosts() {
guard let uid = Auth.auth().currentUser?.uid else { return }
Database.fetchUserWithUID(uid: uid) { (user) in
self.fetchPostsWithUser(user: user)
}
}
var isFinishedPaging = false
fileprivate func fetchPostsWithUser(user: User) {
self.collectionView?.refreshControl?.endRefreshing()
let ref = Database.database().reference().child("posts").child(user.uid)
var query = ref.queryOrdered(byChild: "creationDate")
if posts.count > 0 {
let value = posts.last?.creationDate.timeIntervalSince1970
query = query.queryEnding(atValue: value)
}
query.queryLimited(toLast: 4).observeSingleEvent(of: .value, with: { (snapshot) in
guard var allObjects = snapshot.children.allObjects as? [DataSnapshot] else { return }
allObjects.reverse()
if allObjects.count < 4 {
self.isFinishedPaging = true
} else {
self.isFinishedPaging = false
}
if self.posts.count > 0 && allObjects.count > 0 {
allObjects.removeFirst()
}
allObjects.forEach({ (snapshot) in
guard let dictionary = snapshot.value as? [String: Any] else { return }
var post = Post(user: user, dictionary: dictionary)
post.id = snapshot.key
self.posts.append(post)
})
self.collectionView?.reloadData()
}) { (err) in
print(err)
}
}
I simply want it to load more posts when the user scrolls down.
There may be a query issue or a potential logic issue. Lets assume you want to present posts to the user, with the most recent at the top of the list and allow the user to scroll down to see earlier posts.
Let's address both with an example:
We don't have your structure but keeping it super simple, suppose your posts have the following structure with creation dates
post_0
creation_date: "20180101"
post_1
creation_date: "20180102"
post_2
creation_date: "20180103"
post_3
creation_date: "20180104"
post_4
creation_date: "20180105"
post_5
creation_date: "20180106"
post_6
creation_date: "20180107"
post_7
creation_date: "20180108"
Here's your initial query, order by creation date, which will load the last 4 posts from the 5th to the 8th
var query = ref.queryOrdered(byChild: "creationDate")
Then subsequent queries are ordered by creation date but the ending value is not the creation date but the time elapsed since 1970 of the creation date.
let value = posts.last?.creationDate.timeIntervalSince1970
var query = ref.queryOrdered(byChild: "creationDate").queryEnding(atValue: value)
I would guess you just want to load the next 4 earlier posts. So as this sit in the array, they look like this:
20180108
20180107
20180106
20180105
One way to do that is the get the creationDate of the last post from your dataSource (which will be the oldest post)
20180105
Then query by creationDate, endingAt the creation date of the last post, getting 5 total posts, then remove the last one
20180101
20180102
20180103
20180104
20180105
then reversed
20180105
20180104
20180103
20180102
20180101
and remove the first
20180104
20180103
20180102
20180101
something like this
let lastD = self.postsArray.last
self.postsArray = []
let postsRef = self.ref.child("posts")
let queryRef = postsRef.queryOrdered(byChild: "creation_date")
let queryEndingRef = queryRef.queryEnding(atValue: lastD)
let queryLimitedRef = queryEndingRef.queryLimited(toLast: 5)
queryLimitedRef.observeSingleEvent(of: .value, with: { snapshot in
guard var thisArray = snapshot.children.allObjects as? [DataSnapshot] else { return }
thisArray.reverse()
thisArray.removeFirst()
for post in thisArray {
let theDate = post.childSnapshot(forPath: "creation_date").value as! String
self.postsArray.append(theDate)
}
})
This is how my Firebase database looks like:
I want to get the names "Attack on Nibeiwa", "Fort Capuzzo" and so on instead of the rest of the things. My current code gives my the complete JSON:
let ref = Database.database().reference().child("Battle Details")
ref.observeSingleEvent(of: .value, with: { (snap : DataSnapshot) in
print("\(String(describing: snap.value))")
}) { (err: Error) in
print("\(err.localizedDescription)")
}
To retrieve the names try the following:
let ref = Database.database().reference().child("Battle Details")
ref.observeSingleEvent(of: .value, with: { (snap : DataSnapshot) in
for child in snap.children {
let key = (child as AnyObject).key as String
}
}) { (err: Error) in
print("\(err.localizedDescription)")
}
Here the snapshot is at Battle Details then you iterate inside the direct children which are the names in this case and retrieve the names using child.key
I want to take the save all of my blocked user child as a string in my code. But as simple as it might sound I was not able to figure it out.
static func block(myself: String, posterUID: String){
var blockedUserRef = Database.database().reference().child("users").child(myself).child("blockedUsers").child(posterUID)
blockedUserRef.setValue(true)
var blokedArray:[String] = []
var handle:DatabaseHandle!
blockedUserRef = Database.database().reference()
handle = blockedUserRef.child("blockedUsers").observe(.childAdded, with:{ (DataSnapshot) in
if let item = DataSnapshot.value as? String{
blokedArray.append(item)
}
})
}
I want to take the array of my blocked users go through in for loop and filter them from showing.
ref.observeSingleEvent(of: .value, with: { (snapshot) in
guard let snapshot = snapshot.children.allObjects as? [DataSnapshot]
else { return completion([]) }
// 3 filter the user from the array
let users =
snapshot
.flatMap(User.init)
.filter { $0.uid != currentUser.uid }
Here is my firebase:
"users" : {
"3YLVUDA8YnSuVYUTxv6cvOQPSjm1" : {
"username" : "🌸😍🌸"
},
"4duY2hhTv5S7sSXtZYBfiP7JBLz1" : {
"username" : "Love from NYC"
},
"58t0M2Fxxhg6GRT96vVbKMFHRKO2" : {
"blockedUsers" : {
"4duY2hhTv5S7sSXtZYBfiP7JBLz1" : true,
"SqarOdPJUydcdV6deXTeIdzkarE2" : true
},
"username" : "IStandWithYou"
},
some new ways I am trying I debugged it and it seems that it is not saving it onto the array
///adedblock
var blockedUserRef = Database.database().reference().child("users").child(currentUser.uid).child("blockedUsers")
var blokedArray:[String] = []
var handle:DatabaseHandle!
blockedUserRef = Database.database().reference()
handle = blockedUserRef.child("blockedUsers").observe(.childAdded, with:{ (DataSnapshot) in
if let item = DataSnapshot.value as? String{
blokedArray.append(item)
}
})
for user in blokedArray{
let users =
snapshot
.flatMap(User.init)
.filter { $0.uid != user }
}
This can be done by saving all of the child entries of blockedUsers to an array that will hold all your strings.
To do this, first create an empty array like
myList:[string] = []
Then, you need to create a reference to your Firebase database like:
var ref: DatabaseReference!
You also need a database handle to navigate around your database:
var handle:DatabaseHandle!
Now, you need to go to your ViewDidLoad function and add code like:
ref = Database.database().reference()
handle = ref?.child("blockedUsers").observe(.childAdded, with:{ (DataSnapshot) in
if let item = DataSnapshot.value as? String{
self.myList.append(item)
}
})
This piece of code is checking whether an entry is added to the child database "blockedUsers", and from that, it is adding whatever was just entered into the array.
Now, you have an array filled with whatever was in the child database, blockedUsers. You can now use the array in a UITableView, or list it in a label.
Hope this helped!
I'm using the following query to get the snapshot below.
dbRef.child("users").queryOrdered(byChild: "username").queryStarting(atValue: text).queryEnding(atValue: text+"\u{f8ff}").observe(.value, with: { snapshot in })
But I'm having trouble figuring out how to iterate over the values of the children "username" (i.e. bill, billy, billykins) because they all have the same key ("username"). I'm trying to extract all the names and put them in an array of names.
Snap (users) {
fDrzmwRUt2guh3O8pc792ipyEqA3 = {
username = bill;
};
qyQkIOxSpXgQoUoh0QNvPlkQ1Mp1 = {
username = billy;
};
edSk54xSpXgQoYoh0QNvOlkQ1Mp3 = {
username = billykins;
};
}
This is my function which gets the snapshot and tries to iterate over it. However, the loop crashes:
func findUsers(text: String) {
print("search triggered")
dbRef.child("users").queryOrdered(byChild: "username").queryStarting(atValue: text).queryEnding(atValue: text+"\u{f8ff}").observe(.value, with: { snapshot in
print(snapshot)
for i in snapshot.children{
let value = snapshot.value as! Dictionary<String,String>
let username = value["username"]
print(username)
self.userList.append(username!)
print(self.userList)
}
}) { (error) in
print("searchUsers \(error.localizedDescription)")
}
}
Here's a fraction of the log. Too long to post:
0x1002cg360 <+272>: adr x9, #268929 ; "value type is not bridged to Objective-C"
0x1002cg364 <+276>: nop
0x1002cg368 <+280>: str x9, [x8, #8]
-> 0x1002cg36c <+284>: brk #0x1
0x1002cg370 <+288>: .long 0xffffffe8 ; unknown opcode
Here's the solution I was looking for. I needed to loop through the big snapshot to extract the child snapshots into an array, and then loop through the child snapshots by value to get the usernames:
func findUsers(text: String) {
print("search triggered")
dbRef.child("users").queryOrdered(byChild: "username").queryStarting(atValue: text).queryEnding(atValue: text+"\u{f8ff}").observe(.value, with: { snapshot in
print(snapshot)
if ( snapshot.value is NSNull ) {
print("not found")
} else {
var blaArray = [FIRDataSnapshot]()
for child in snapshot.children {
let snap = child as! FIRDataSnapshot //downcast
blaArray.append(snap)
}
for child in blaArray {
let dict = child.value as! NSDictionary
let username = dict["username"]!
print(username)
}
}) { (error) in
print("searchUsers \(error.localizedDescription)")
}
}
Adapted from this post: Get data out of array of Firebase snapshots