How can I delete a specific child node in Firebase from UITableViewCell using Swift

Question

I have a UITableView which looks like this image

.

When I swipe to delete th

Answer 1

It's a fairly straightforward process:

In general, a datasource for tableViews is an array. That array is built from dictionaries read from Firebase snapshots - or an array of objects built from the snapshots (recommended).

So here's an example that matches your Firebase structure (this was populated from a single node from a snapshot)

class Exercise {
    key: "KWc7RTuOe5PefiMM2tL"
    bodyPart: "Legs"
    exerciseName: "Test 3 "
    userId: "8rHmyTxdocTEvk1ERiiavjMUYyD3"
}

Then, when the user swipes row 3 for example, retrieve the Exercise object from the array, row3.

let theObject = ExerciseArray[3]
let parentNode = theObject.key
let ref = rootNode.child(parentNode)
ref.setValue(nil)

and you're done.

Answer 2

Following on from what MHDev has already answered:

func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
    if editingStyle == .delete {

        if let exerciseName = exercises[indexPath.row].exerciseName {

            let ref = FIRDatabase.database().reference().child("userExercises")

            ref.queryOrdered(byChild: "exerciseName").queryEqual(toValue: exerciseName).observe(.childAdded, with: { (snapshot) in

                snapshot.ref.removeValue(completionBlock: { (error, reference) in
                    if error != nil {
                        print("There has been an error:\(error)")
                    }
                })

            })

        }

        exercises.remove(at: indexPath.row)
        tableView.deleteRows(at: [indexPath], with: .left)
    }
}

Answer 3

To solve this issue I tried a number of different methods before finally reaching my intended result.

To delete the value, I created a reference to the child node 'userExercises', then ordered it by 'exerciseName' and then .queryEqual(toValue:) the exercise name value which I extracted form the UITableViewCell.

I then removed the snapshot value of this and the example code is below:

func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
    if editingStyle == .delete {

        if let exerciseName = exercises[indexPath.row].exerciseName {

            let ref = FIRDatabase.database().reference().child("userExercises")

            ref.queryOrdered(byChild: "exerciseName").queryEqual(toValue: exerciseName).observe(.childAdded, with: { (snapshot) in

                snapshot.ref.removeValue(completionBlock: { (error, reference) in
                    if error != nil {
                        print("There has been an error:\(error)")
                    }
                })

            })

        }

        exercises.remove(at: indexPath.row)
        tableView.deleteRows(at: [indexPath], with: .left)
    }
}