I have a profile class and settings class
profile class contains an internal function
class Profile: UIViewController,UIImagePickerControllerDelegate,UINavigationControllerDelegate {
internal func profileSelectFromGallery(sender: Profile){
let myPickerController = UIImagePickerController()
myPickerController.delegate = sender;
myPickerController.sourceType =
UIImagePickerControllerSourceType.PhotoLibrary
sender.presentViewController(myPickerController, animated:true, completion: nil)
}
}
I want to use profileSelectFromGallery in setting class and I have two tries below
class SettingsVC: UITableViewController {
// I will call this private function on a click events
private func selectFromGallery(){
// let profile = Profile()
// profile.profileSelectFromGallery(self)
Profile.profileSelectFromGallery(self)
}
}
The above codes results into Cannot convert value of type 'SettingsVC' to expected argument type 'Profile'
since profileSelectFromGallery
needs a parameter of a class Profile
so what i want to do is change sender so that i can use it from any of my class and not just my Profile class .
So the problem is that you can't convert a SettingsVC
into a Profile
. If you look at the method signature you'll see it's expecting a Profile
:
internal func profileSelectFromGallery(sender: Profile)
You are trying to pass in a SettingVC in selectFromGallery()
Inside profileSelectFromGallery
you want the sender to be both a UIViewController
and a UIImagePickerControllerDelegate
. There's a couple ways you could do this:
The simplest is to change the method signature. You'd do something like this:
internal func profileSelectFromGallery(sender: UIImagePickerControllerDelegate){
guard let vc = sender as? UIViewController else {
return
}
let myPickerController = UIImagePickerController()
myPickerController.delegate = sender;
myPickerController.sourceType =
UIImagePickerControllerSourceType.PhotoLibrary
vc.presentViewController(myPickerController, animated:true, completion: nil)
}
Theres 2 main things here: sender
is changed to the proper delegate method, and theres a guard
statement to cast it to a VC for the presentViewController
call.
The much more awesome way to do this is to use protocol extensions!
extension UIImagePickerControllerDelegate where Self: UIViewController, Self: UINavigationControllerDelegate {
func profileSelectFromGallery() {
let myPickerController = UIImagePickerController()
myPickerController.delegate = self
myPickerController.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
self.presentViewController(myPickerController, animated:true, completion: nil)
}
}
Basically what I'm doing here is adding a method for every UIImagePickerControllerDelegate
thats also an UIViewController
and an UINAvigationControllerDelegate
. This means that I can call it on both Profile and SettingVC (once you add the necessary delegates to SettingVC). All you would need to do is:
let profile = Profile()
profile.profileSelectFromGallery()
let settingVC = SettingVC()
settingVC.profileSelectFromGallery()
Declare new protocol as:
protocol PickerProtocol : UIImagePickerControllerDelegate, UINavigationControllerDelegate {
}
Now your Profile class will look like:
class Profile: UIViewController, PickerProtocol {
//Option 1
internal func profileSelectFromGallery(contoller: UIViewController, pickerProtocol: PickerProtocol){
let myPickerController = UIImagePickerController()
myPickerController.delegate = pickerProtocol
myPickerController.sourceType =
UIImagePickerControllerSourceType.PhotoLibrary
contoller.presentViewController(myPickerController, animated:true, completion: nil)
}
//Option 2
internal func profileSelectFromGalleryOption2(sender : UIViewController? ) {
var viewContoller : UIViewController = self
if let unwrappedSender = sender {
viewContoller = unwrappedSender
}
let myPickerController = UIImagePickerController()
if let pickerProtocol = viewContoller as? PickerProtocol {
myPickerController.delegate = pickerProtocol
} else {
myPickerController.delegate = self //Assign self as default
}
myPickerController.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
viewContoller.presentViewController(myPickerController, animated:true, completion: nil)
}
}
class SettingsVC1: UITableViewController {
// I will call this private function on a click events
private func selectFromGallery(){
let profile = Profile()
profile.profileSelectFromGallery(self, pickerProtocol:profile)
profile.profileSelectFromGalleryOption2(self)
//Or
profile.profileSelectFromGalleryOption2(nil)//profile itself delegate and presenting controller
}
}
// OR
class SettingsVC2: UITableViewController, PickerProtocol {
// I will call this private function on a click events
private func selectFromGallery(){
let profile = Profile()
profile.profileSelectFromGallery(self, pickerProtocol:self)
profile.profileSelectFromGalleryOption2(self)
//Or
profile.profileSelectFromGalleryOption2(nil)//profile itself delegate and presenting controller
}
}
I would use POP (protocol oriented programming) like this:
protocol SelectorProtocol: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
}
extension SelectorProtocol where Self: UIViewController {
func profileSelectFromGallery() {
let myPickerController = UIImagePickerController()
myPickerController.delegate = self;
myPickerController.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
self.presentViewController(myPickerController, animated:true, completion: nil)
}
}
class Profile: UIViewController,UIImagePickerControllerDelegate,UINavigationControllerDelegate, SelectorProtocol {
func foo() {
profileSelectFromGallery()
}
}
class SettingsVC: UITableViewController, SelectorProtocol {
// I will call this private function on a click events
private func selectFromGallery(){
profileSelectFromGallery()
}
}
You are trying to statically call profileSelectFromGallery:
even though it is an instance method.
Try changing the method definition to:
internal static func profileSelectFromGallery(sender: Profile){
As for being able to use any class as a delegate, create a custom Protocol
and ensure that the sender
conforms to this protocol. See here (specifically the heading titled Protocols
) for more information: http://www.raywenderlich.com/115300/swift-2-tutorial-part-3-tuples-protocols-delegates-and-table-views
perhaps the following will work:
class SettingsVC: UITableViewController {
// I will call this private function on a click events
private func selectFromGallery(){
let prof = Profile()
prof.profileSelectFromGallery(prof)
}
}
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