Read from Firebase to UIpickerView

Question

I have some trouble doing the following:

1. Read from Firebase database.
2. Add the information to my UIpickerView as "options"
3. Show "options" in the app.

What I want to achieve is to read from "Time report" and display the "user names" as "options" in the UIpickerView (in the "dropdown menu").

(The plan is to later be able to display the information in each of the "options" in the same view. Something like choosing a "User" in a app and having the users "stats" displayed.)

Any help would be great!

This is my code: Well for now, I dont really have code as everything i'v tried seems not to work. Last working code was:

    func fetchUser()
{
    ref = Database.database().reference() //Set the reference//

    databaseHandle = ref?.child("Time report").observe(.childAdded, with: { (snapshot) in

        print (snapshot)
    })
}

My database looks like: (Login is the first node. Meaning its the node closest to the root - if that makes any sens.)

My Results Well, for now - I only get Fred, Kalle and Ivar printed, with all their information...

I've tried:

• To change "childAdded" to Value. No go..
• Make it work with only one node. Meaning just having "Ivar" and a couple of random values. Printed in console - but nothing in the pickerview.

Used this video to aid in create a pickerView.

Answer 1

Here's how it's done. I am assuming you know how to populate a dataSource for your pickerView in general. If you need help with that, it would be best addressed as a separate question.

Assume we are using a structure like the one in the original question:

  time_report
    adam
      gym
        timestamp_0
          From : "from_0",
          To : "to_0"
        timestamp_1
          From : "from_1",
          To : "to_1"
      home : {
        timestamp_0
          From : "from_0",
          To : "to_0"
      work : {
        timestamp_0
          From : "from_0",
          To : "to_0"

Notes:

1) best practice is to not use spaces in keys so I am using time_report
2) It's not clear if under each option (gym, home, work) there will be
      multiple nodes so I included two under gym for demonstration purposes
3) I am using placeholders for timestamps from_0, to_0 etc but you get the idea.
4) This will handle any situation for options; they could be gym, home, work
       or A, B, C or whatever the key names are.
5) Nothing is hard coded so as timestamps change, the code continues to work

Now to read the options (gym, home, work or whatever they may be) for the adam node here's the code.

let timeReportRef = self.ref.child("time_report")
let adamRef = timeReportRef.child("adam")
adamRef.observeSingleEvent(of: .value, with: { snapshot in
    for child in snapshot.children {
        let snap = child as! DataSnapshot
        let nodeKey = snap.key //will be gym, home, work
        print(nodeKey)
        //populate your dataSource Array here with the nodeKeys
        //the following code could be used to populate a structure with additional
        //  info so when the user taps 'gym', we have already loaded the gym data
        //   and can populate another view controller with the details
        for childTimes in snap.children { //the child nodes under gym, home, work
            let timeSnap = childTimes as! DataSnapshot
            let timeKey = timeSnap.key
            let dict = timeSnap.value as! [String: Any]
            let from = dict["From"] as! String
            let to = dict["To"] as! String

            print("  timestamp: \(timeKey)")
            print("     from: \(from)")
            print("       to: \(to)")
        }
    }
})

and the output

gym
  timestamp: timestamp_0
     from: from_0
       to: to_0
  timestamp: timestamp_1
     from: from_1
       to: to_1
home
  timestamp: timestamp_0
     from: from_0
       to: to_0
work
  timestamp: timestamp_0
     from: from_0
       to: to_0

The important bit here is that if you just want to add gym, home, work to your pickerView, you can omit the For loop. However. That loop demonstrates how to load additional data (timestamps) under gym, home and work.

There's a couple of directions to go from here. If you want to load the firebase data from Firebase when the user taps gym for example, you would get what the user tapped (gym) and you are in the adam section so it would be

let user = userSection //assume we are in the 'adam' section
let option = optionTapped //assume the user tapped gym

let userOptionRef = self.ref.child(user).child(option)
userOptionRef.observeSingleEvent(.value.... etc etc to read in that data.

Another option would be to read it all in at one time, as in the code I provided)\, and populate a class with that info. Then store the class in a dataSource array to be used in the picker.

class userStuff {
   option = ""
   data: DataSnapshot?
}

populate that class or stuct within the closure I presented and then store it in an array. Then in your pickerView, as it's being updated, get the userStuff class from the array for the row and read the option text. If the user then taps on row 0, 'gym' read the array, row 0, get the dataSnapshot and iterate over it to populate a sub view with the timestamp info.

Edit

Original question was changed and in response to a comment here:

let timeReportRef = self.ref.child("Time report")
timeReportRef.observeSingleEvent(of: .value, with: { snapshot in
    for child in snapshot.children {
        let snap = child as! DataSnapshot
        print(snap.key)
    }
})

output will be

Fred
Ivar
Kalle