Can't get DatabaseReference for user in Firebase

Question

I have two initializers. First where snapshot is being "broken down" into its raw data (strings etc) within the firebase closure and the second is convenient one.

   struct UserInfo{
let ref: DatabaseReference?
let key: String
let firstName: String
let lastName: String
let username: String
let pictureURL : String?
let training : [String]?
let uid: String
let admin: Bool

init(firstName: String, lastName:String,username:String,pictureURL:String?,training:[String]?,uid:String,admin:Bool, key:String = "" ){
    self.ref = nil
    self.key = key
    self.firstName = firstName
    self.lastName = lastName
    self.username = username
    self.pictureURL = pictureURL
    self.training = training
    self.uid = uid
    self.admin = admin
    
}

init?(snapshot: DataSnapshot){
    guard let value = snapshot.value as? [String:AnyObject],
          let firstName = value["firstName"] as? String,
          let lastName = value["lastName"] as? String,
          let username = value["userName"] as? String,
          let profilePic = value["pictureURL"] as? String,
          let training = value["Training"] as? [String],
          let uid = value["uid"] as? String,
          let admin = value["isAdmin"] as? Bool
            
    else {return nil}

    self.ref = snapshot.ref
    self.key = snapshot.key
    self.firstName = firstName
    self.lastName = lastName
    self.username = username
    self.pictureURL = profilePic
    self.training = training
    self.uid = uid
    self.admin = admin
}

For getting data fist init works well but when I try to get data with second init my ref value is nill.

DataObjects.infoRef.child(uid!).observe(.value){ snapshot,error in
        var newArray: [UserInfo] = []
            if let dictionary = snapshot.value as? [String:Any]{
                let username = dictionary["username"] as! String
                let firstName = dictionary["firstName"] as! String
                let lastName = dictionary["lastName"] as! String
                let profilePic = dictionary["pictureURL"] as? String
                let training = dictionary["Training"] as? [String]
                let uid = dictionary["uid"] as! String
                let admin = dictionary["isAdmin"] as! Bool
                let userInformation = UserInfo(firstName: firstName, lastName: lastName, username: username,pictureURL: profilePic,training: training, uid: uid, admin: admin)
                let user = UserInfo(snapshot: snapshot)

I set breakpoint at user and userInformations and this is what I get.

user:

userInformations:

Answer 1

This is more of guidance and observation than an answer; maybe it will help.

If you look at your code, the userInformation and user vars are initialized one after the other:

let userInformation = UserInfo(firstName:...
let user = UserInfo(snapshot: snapshot)

So then looking at the screenshots, the first one has the ref var being nil

Which is correct because that the first init call doesn't init the ref var

init(firstName: ...
    self.ref = nil

but then when the second line executes, it does init the ref var in the init

init?(snapshot:...
   self.ref = snapshot.ref

so then it's populated

and then, I created a minimal version of your struct

struct UserInfo{
    let firstName: String

    init(firstName: String ){
        self.firstName = firstName
    }

    init?(snapshot: DataSnapshot) {
        guard let value = snapshot.value as? [String:Any], let firstName = value["name"] as? String else { return nil }

        self.firstName = firstName
        print(snapshot.ref) //this prints the path the the snapshot e.g. it's not nil
    }
}

and then code to populate the two vars and print them to console

func test() {
    let uid = "uid_0"
    self.ref.child("users").child(uid).observe(.value){ snapshot,error in
        var newArray: [UserInfo] = []
        if let dictionary = snapshot.value as? [String:Any] {
            let firstName = dictionary["name"] as! String
            let userInformation = UserInfo(firstName: firstName)
            let user = UserInfo(snapshot: snapshot)

            print(userInformation)
            print(user)
        }
    }
}

and when I run the code, both are correctly populated

UserInfo(firstName: "Jay")
Optional(MyFirebase.ViewController.UserInfo(firstName: "Jay"))

Of course the optional var (second printed line) is showing as optional because it was defined that way.

So the bottom line is that I don't think the issue in the question is actually an issue.