Swift 4 Unwrapping Dictionary from Firebase - swift

Question

Here is the output of "print(dict)"...
["2018-10-17 11:19:51": {
firstname = Brooke;
id = 40vI7hApqkfX75SWsqIR6cdt7xV2;
lastname = Alvarez;
message = hshahyzhshbsbvash;
username = poiii;
}]
["2018-10-17 11:20:31": {
firstname = Trevor;
id = 40vI7hApqkfX75SWsqIR6cdt7xV2;
lastname = Bellai;
message = hey;
username = br9n;
}]
["2018-10-17 11:20:44": {
firstname = Amy;
id = 40vI7hApqkfX75SWsqIR6cdt7xV2;
lastname = Ikk;
message = hey;
username = nine9;
}]
My code...
Database.database().reference().child("recent-msgs").child(uid!).observe(.childAdded) { (snapshot: DataSnapshot) in
if let dict = snapshot.value as? [String: Any] {
print(dict)
// Store data in user.swift model
let firstnameData = dict[0]["firstname"] as! String
let idData = dict["id"] as! String
let lastnameData = dict["lastname"] as! String
let messageData = dict["message"] as! String
let usernameData = dict["username"] as! String
let rankData = dict["rank"] as! String
let propicrefData = dict["propicref"] as! String
let convoinfo = RecentConvo(firstnameString: firstnameData, idString: idData, lastnameString: lastnameData, messageString: messageData, usernameString: usernameData, rankString: rankData, propicrefString: propicrefData)
self.recentconvos.append(convoinfo)
print(self.recentconvos)
self.tableView.reloadData()
}
}
I'm trying to retrieve the dictionary within the first dictionary which is the value to the key which is the date associate with it. For example: 2018-10-17 11:19:51. However I cannot use this exact string to call it because I must do this without the knowledge of that string.
I tried this:
let firstnameData = dict[0]["firstname"] as! String
But it returns an error:
Cannot subscript a value of type '[String : Any]' with an index of type 'Int'

Answer 1

The error noted above is showing up because you were trying to access the element at a certain position (0) from the dictionary. Dictionaries are not ordered lists, and hence won't have a fixed order of elements to be accessed.
The logged dictionary doesn't really look like a dictionary. Assuming that it is a dictionary, and its keys are the date strings, you can use the following code snippet to parse the dictionary.
class RecentConversation {
var id: String?
var firstName: String?
var lastName: String?
var message: String?
var username: String?
var rank: String?
var propicref: String?
init?(dictionary: [String: Any]?) {
guard let dict = dictionary else {
// Return nil in case the dictionary passed on is nil
return nil
}
id = dict["id"] as? String
firstName = dict["firstname"] as? String
lastName = dict["lastname"] as? String
message = dict["message"] as? String
username = dict["username"] as? String
rank = dict["rank"] as? String
propicref = dict["propicref"] as? String
}
}
Usage:
let dateStrings = dict.keys.sorted {
// Sort in chronological order (based on the date string; if you need to sort based on the proper date,
// convert the date string to Date object and compare the same).
//
// Swap the line to $0 > $1 to sort the items reverse chronologically.
return $0 < $1
}
var conversations: [RecentConversation] = []
for date in dateStrings {
if let conversation = RecentConversation(dictionary: (dict[date] as? [String: Any])) {
conversations.append(conversation)
}
}

Answer 2

You were all very helpful, so I would like to start off by saying thank you. I went ahead and applied the method that lionserdar explained. (.allKeys)
// Fetch Recent Messages
func fetchRecentMsgs() {
// Direct to database child
Database.database().reference().child("recent-msgs").child(uid!).observe(.childAdded) { (snapshot: DataSnapshot) in
if let dict = snapshot.value as? NSDictionary {
print(dict)
print(dict.allKeys)
let keys = dict.allKeys
for key in keys {
print(key)
if let nestedDict = dict[key] as? [String: Any] {
print(nestedDict)
let firstnameData = nestedDict["firstname"] as! String
let idData = nestedDict["id"] as! String
let lastnameData = nestedDict["lastname"] as! String
let messageData = nestedDict["message"] as! String
let usernameData = nestedDict["username"] as! String
Worked for me so I hope this will help others too!