Subclass UIPickerView swift - ios

Question

I'm trying to create a subclass of UIPickerView so I can use my picker in multiple views. I'm trying to call my picker programmatically as inputView of a UITextField but I can't figure out how to initialise it correctly. I'm in doubt if this is the right approach and how I can get it to work. I hope any of you can help me.
UIPickerView subclass:
import UIKit
class GroupPicker : UIPickerView, UIPickerViewDelegate, UIPickerViewDataSource{
var cdm = CoreDataManager()
var groupObjList : [Group]!
init() {
groupObjList = cdm.groupList()
}
//MARK: - Delegates and data sources
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return groupObjList.count
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
return groupObjList[row].title
}
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
println("picked \(groupObjList[row].title)")
}
}
How I try to call it in the view controller:
override func viewDidLoad() {
super.viewDidLoad()
groupPicker = GroupViewPicker() //instead of UIPickerView()
groupField.inputView = groupPicker
}

Answer 1

You have to override your init method
required init(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override init(frame: CGRect) {
super.init(frame:frame)
self.delegate = self
self.dataSource = self
}

Answer 2

It was easy like this.
GroupPicker : UIPickerView {
override init(frame: CGRect){
super.init(frame: frame)
self.groupObjList = cdm.groupList()
}
}
Call it:
viewDidLoad() {
groupField.inputView = GroupPicker(frame: CGRectZero)
}

Answer 3

I presume you will want to present this modally?
If so, you could do the following:
override func viewDidLoad() {
super.viewDidLoad()
groupPicker = GroupViewPicker() //instead of UIPickerView()
//Send the data you want your picker view to handle.
groupPicker.groupObjList = dataForPickerView
self.presentViewController(viewControllerToPresent: groupPicker, animated: , completion: nil)
}
And it should pop up and present itself modally
Tip:
This var groupObjPicker: [Group]! will blow up if you never pass in a group to this array (i.e. you dont set the property as shown above). A safer (depending on what you are trying to achieve ofc.) would be to declare it as an empty array like such var groupObjList = [Group](). Then you know that if nothing is passed to it, it will at least just return 0 when .count is called on it etc.