CODEWITHSUNDEEP
iosswiftfirebase
Michael Williams
Michael Williams

Reputation: 1412

Retrieve randomly generated child ID from Firebase

I have Firebase generating random keys for my records in a Swift app. How do I go about retrieving that key if I want to change a specific record? In my example below, I'm marking a task complete but when I hit the button it doesn't work as intended because I am not referencing the particular task but to reference the task I need the randomly generated key.

 func doneHit(cell:TaskCell) {
        if let ip = tableView.indexPathForCell(cell) {
            var task = tasksInSectionArray[ip.section][ip.row]
            let tasksRef = ref.childByAppendingPath("tasks")
            ref.observeSingleEventOfType(.Value, withBlock: { snapshot in
                let doneRef = tasksRef.childByAppendingPath("\(snapshot.key)/done")
                if task.done == false {
                    task.done = true
                    cell.checkBox.image = UIImage(named: "checkedbox")
                    doneRef.setValue(task.done)
                }
                else {
                    task.done = false
                    cell.checkBox.image = UIImage(named: "uncheckedbox")
                    doneRef.setValue(task.done)
                }
                let completedByRef = tasksRef.childByAppendingPath("\(snapshot.key)/completedBy")
                if task.done == true {
                    completedByRef.setValue(self.user)
                    cell.detailLabel.text = "Completed By: \(self.user)"
                }
                else {
                    completedByRef.setValue("")
                    cell.detailLabel.text = ""
                }
                })
        }
    }

My Firebase structure:

  1. tasks
    • randomly generated ID
      • title:
      • description:
    • randomly generated ID
      • title:
      • description:

Update 1:

I have updated my code to get the IDs for all of the tasks but the functionality of updating the backend isn't working properly. It is only letting update the tasks created in the app. There are 150 tasks that I imported using the web Dashboard. Those are the ones I can't get to update.

func doneHit(cell:TaskCell) {
        if let ip = tableView.indexPathForCell(cell) {
            var task = tasksInSectionArray[ip.section][ip.row]
            let tasksRef = ref.childByAppendingPath("tasks")
            var taskID = ""
            tasksRef.observeSingleEventOfType(.Value, withBlock: { snapshot in
                for task in snapshot.children {
                    let _tasks = task as! FDataSnapshot
                    let id = _tasks.key
                    print(id)
                    taskID = id
                }
                let doneRef = tasksRef.childByAppendingPath("\(taskID)/done")
                if task.done == false {
                    task.done = true
                    cell.checkBox.image = UIImage(named: "checkedbox")
                    doneRef.setValue(task.done)
                }
                else {
                    task.done = false
                    cell.checkBox.image = UIImage(named: "uncheckedbox")
                    doneRef.setValue(task.done)
                }
                let completedByRef = tasksRef.childByAppendingPath("\(taskID)/completedBy")
                if task.done == true {
                    completedByRef.setValue(self.user)
                    cell.detailLabel.text = "Completed By: \(self.user)"
                }
                else {
                    completedByRef.setValue("")
                    cell.detailLabel.text = ""
                }
                })
        }
    }

Upvotes: 8

Views: 11875

Answers (4)

Dracula
Dracula

Reputation: 3090

An alternative to Ron's answer involves generating the key first and then using it to set value:

let autoId = databaseReference.childByAutoId().key
databaseReference.child(autoId).setValue(YOUR_VALUE)

Upvotes: 0

ttorbik
ttorbik

Reputation: 408

Following Tim's answer for Swift 3 and Firebase 4 I had to use the below

for task in snapshot.children {
            guard let taskSnapshot = task as? DataSnapshot else {
                continue
            }

            let id = taskSnapshot.key

Upvotes: 1

Tim Vermeulen
Tim Vermeulen

Reputation: 12562

tasksRef.observeSingleEventOfType(.Value, withBlock: { snapshot in
    for task in snapshot.children {
        guard let taskSnapshot = task as? FDataSnapshot else {
            continue
        }

        let id = task.key
        // do other things
    }
}

Upvotes: 5

Ron Harlev
Ron Harlev

Reputation: 16703

To create a randomly generated key you need to use childByAutoId() (which I can't see in your example code).
This will return a Firebase reference you could use and which will return the key with it's .key property

var post1Ref = ref.childByAutoId()
post1Ref.setValue(post1)

var postId = post1Ref.key

See documentation here

Upvotes: 27

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