Firebase/Swift two database-connections - swift

Question

I have an application where I would like to connect to two different firebase-databases.
I have two viewControllers which are individually able to connect to each database, but if I connect to the first database, and afterwards connect to the other - the app Crashes
I have 2 info.plist files and 2 ViewControllers connected with a button/segue.
this is my first viewController
import UIKit
import Firebase
class ViewController: UIViewController {
var ref: DatabaseReference!
var handle:UInt!
override func viewDidLoad() {
super.viewDidLoad()
let filePath = Bundle.main.path(forResource: "GoogleService-Info-anden", ofType: "plist")
guard let fileopts = FirebaseOptions.init(contentsOfFile: filePath!)
else { assert(false, "Couldn't load config file") }
FirebaseApp.configure(options: fileopts)
ref = Database.database().reference()
ref?.child("UserVandreture").child("navn").setValue("Inger")
}
override func viewDidDisappear(_ animated: Bool) {
ref.removeObserver(withHandle: handle)
}
}
I can connect to firebase - which happens when I load the app.
Second viewController
import UIKit
import Firebase
class AndenDBViewController: UIViewController {
var ref: DatabaseReference!
var handle:UInt!
let fileName = "Bambusstien"
override func viewDidLoad() {
super.viewDidLoad()
let filePath = Bundle.main.path(forResource: "GoogleService-Info", ofType: "plist")
guard let fileopts = FirebaseOptions.init(contentsOfFile: filePath!)
else { assert(false, "Couldn't load config file") }
FirebaseApp.configure(options: fileopts)
ref = Database.database().reference()
response()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
//kan læse navn,type, længde og link
func response() {
ref?.child("Vandreture").child(fileName).observe(.value, with: { (snapshot) in
let dict = snapshot.value as? [String: AnyObject]
let navn = dict!["navn"] as? String
print(navn as Any)
let type = dict!["type"] as? String
print(type as Any)
let Længde = dict!["length"] as? String
print(Længde as Any)
let link = dict!["link"] as? String
print(link as Any)
})
}
override func viewDidDisappear(_ animated: Bool) {
ref.removeObserver(withHandle: handle)
}
}
If I out-comment the database call in the previous viewController, this controller is also able to connect to firebase/database and read data, but if I don't outcomment this data, it will set the value in the first database, and when I press the button to go to the second viewController the app crashes.
I have set the targetMemebeship for the 2 plist-files to the same application-name.
The error message says that the app has already been configured - however I thought that ref.removeObserver(handle) in ViewDidDissapear() would disconnect the connection to the database, before connecting to the other database - so what is wrong??

Answer 1

Basically i needed protection of my data, but I had not populated the databases yet so..
The solution to my problem was to work with the rules-part - having just a single database.
Allowing users to have write-access to certain part of the database, and only having read-access to other parts - something like:
{
"rules": {
"myPersonal":{
".read": true,
".write": "auth != null"
},
"myPublic": {
".read": "auth != null",
".write": true
}
}
}