database structure
I am trying to get an array of users(strings) from a comment, but am having trouble since it is kinda deep in my database, here is the implementation I've tried, it is returning 0 for the count.
REF_FEEDMESSAGES.child(messageKey).child("comments").observeSingleEvent(of: .value) { (commentSnapshot) in
guard let commentSnapshot = commentSnapshot.children.allObjects as? [DataSnapshot] else {return}
for comment in commentSnapshot {
let theComment = comment.value as? [String: Any]
let theContent = theComment?["content"] as? String ?? ""
let theIcon = theComment?["icon"] as? String ?? ""
let theColor = theComment?["color"] as? String ?? ""
let theDate = theComment?["date"] as? String ?? "0"
let theName = theComment?["userName"] as? String ?? ""
let theVerified = theComment?["isVerified"] as? String ?? "no"
let profileImageURL = theComment?["profileImageURL"] as? String ?? ""
let postedBy = theComment?["postedBy"] as? String ?? ""
let likes = theComment?["likes"] as? String ?? ""
let key = comment.key
let likers = comment.childSnapshot(forPath: "likedBy").value as? [String] ?? []
print(likers.count)
guard let likers = comment.childSnapshot(forPath: "likedBy").children.allObjects as? [DataSnapshot] else {return}
for like in likers {
let theLike = like.value as? [String:Any]
print(theLike!["user"] as? String ?? "")
commentLiked.append(theLike!["user"] as? String ?? "")
}
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.
Please anyone who would show me how to include the snapshot key value along with children value that I already append to my array (forgot to include it and now remember I have to) ... aside from that something really I couldn't understand when I tried to solve my own issue, by testing the value first by using this method: print(rooms.popFirst().key!) half of my database values got nil value ?!! and if I don't include that method everything works fine anyways if you can't imagine that nonetheless I really wish your suggestion or advice for getting all data with their own key value...
This is my code so far:
Database.database().reference().child("rooms").observe(.value, with: { (snapshot) in
print()
var rooms = snapshot.value as! [String:AnyObject]
for(_,value) in rooms {
if (rooms.popFirst()?.key) != nil{
let title = value["title"] as? String
let description = value["description"] as? String
let roomPictureUrl = value["Room Picture"] as? String
let longitude = value["Longtitude"] as? String
let latitude = value["Latitude"] as? String
let dateFrom = value["Date From"] as? String
let dateTo = value["Date To"] as? String
let owner = value["Owner"] as? String
let myRooms = Room(roomID: "XXX",title: title!, description: description!, roomPicutreURL: roomPictureUrl!, longitude: longitude!, latitude: latitude!, dateFrom: dateFrom!, dateTo: dateTo!, owner: owner!)
//print(rooms.popFirst()?.key)
self.rooms.append(myRooms)
self.tableView.reloadData()
}
}
})
Try this:
Database.database().reference().child("rooms").observe(.value, with: { (snapshot) in
var rooms = snapshot.value as! [String:AnyObject]
let roomKeys = Array(rooms.keys)
for roomKey in roomKeys {
guard
let value = rooms[roomKey] as? [String:AnyObject]
else
{
continue
}
let title = value["title"] as? String
let description = value["description"] as? String
let roomPictureUrl = value["Room Picture"] as? String
let longitude = value["Longtitude"] as? String
let latitude = value["Latitude"] as? String
let dateFrom = value["Date From"] as? String
let dateTo = value["Date To"] as? String
let owner = value["Owner"] as? String
let myRooms = Room(roomID: "XXX",title: title!, description: description!, roomPicutreURL: roomPictureUrl!, longitude: longitude!, latitude: latitude!, dateFrom: dateFrom!, dateTo: dateTo!, owner: owner!)
print(roomKey)
self.rooms.append(myRooms)
self.tableView.reloadData()
}
}
})
To get the key from snapshot you can use following lines of code it will give you result like -> Kqwewsds12 -> your child Details
let dictValues = [String](snapshot.keys)
print(dictValues[0]) //Output -- Kqwewsds12
I have parsed the JSON data, now while setting the JSON to my NSDictionary there might be certain keys in the JSON that might not be present. I want to check if the key is present in the JSON parsed to me and if not, set blank field as value to the key in the `NSDictionary' object.
jsonData = ["id": ((json["idnumber"]) as? String!)!,
"Name": ((json["name"]) as? String!)!,
"Roll Number": ((json["rollnumber"]) as? String!)!,
"Class": ((json["class"]) as? String!)!,
"Marks": ((json["marks"]) as? String!)!,
"Gender": ((json["gender"]) as? String!)!]
So in the above case, the marks field may or may not be present in the JSON. I want to check this and assign respective value to the corresponding key in jsonData.
I tried using "??", but it takes lot of compilation time.
You can use if let or guard for conditional optional wrapping for that like this.
var jsonData = [String : String]
if let num = json["idnumber"]) as? String {
jsonData["id"] = num
}
else {
jsonData["id"] = num
}
and so on for others.
Edit: You can also try like this.
var id = name = rollNum = class = ""
if let num = json["idnumber"]) as? String {
id = num
}
if let sname = json["name"]) as? String {
name = sname
}
...
Then at last create Dictionary
var jsonData = ["id": id, "name": name, ...]
You can set the value if present otherwise blank string (""). This will prevent crash. Try below code:-
let idValue = dictionary["idnumber"] as? String ?? ""
let name = dictionary["name"] as? String ?? ""
let rollNumber = dictionary["rollnumber"] as? String ?? ""
let className = dictionary["class"] as? String ?? ""
let marks = dictionary["marks"] as? String ?? ""
let gender = dictionary["gender"] as? String ?? ""
let jsonDic : NSMutableDictionary = NSMutableDictionary()
jsonDic.setObject(idValue, forKey: "id")
jsonDic.setObject(name, forKey: "name")
jsonDic.setObject(className, forKey: "class")
jsonDic.setObject(rollNumber, forKey: "rollNumber")
jsonDic.setObject(marks, forKey: "marks")
jsonDic.setObject(gender, forKey: "gender")
I'm not sure how to fix this error. Can someone explain it?
Type 'NSFastEnumerationIterator.Element' (aka 'Any') does not conform to protocol 'AnyObject'
Here's my Query.
media24HourQuery.observe(FIRDataEventType.value, with: { snapshot in
var newItems = [[String: AnyObject]]()
for child in snapshot.children {
let title = (child as AnyObject).value["title"] as? String
let userID = (child as AnyObject).value["userID"] as? String
let mediaID = (child as AnyObject).value["mediaID"] as? String
let timestamp = (child as AnyObject).value["timestamp"] as? Double
edit: this doesn't work either (everything is nil)
for _ in snapshot.children {
let title = (snapshot.value as? NSDictionary)?["title"] as? String
let userID = (snapshot.value as? NSDictionary)?["userID"] as? String
let mediaID = (snapshot.value as? NSDictionary)?["mediaID"] as? String
let timestamp = (snapshot.value as? NSDictionary)?["timestamp"] as? Double
and if I do print (child), this is what I get:
// print(child)
Snap (XsUwNDQB3qPdjYFCOLzANmsjjpf1-1474144681) {
mediaID = "XsUwNDQB3qPdjYFCOLzANmsjjpf1-1474144681";
timestamp = 1474144681490;
title = "outside sep 17";
userID = XsUwNDQB3qPdjYFCOLzANmsjjpf1;
}
edit: solved it. this works:
let snapDic = snapshot.value as? NSDictionary
for child in snapDic! {
print (child)
let childDic = child.value as? NSDictionary
let title = childDic?["title"] as? String
let userID = childDic?["userID"] as? String
let mediaID = childDic?["mediaID"] as? String
let timestamp = childDic?["timestamp"] as? Double