Call function from UICollectionViewCell to use in UICollectionView - swift

Question

I have a UICollectionViewCell that creates a bunch of text fields and a function (handleNewJob) that looks at all the textfields created in the cell and writes them to firebase.
However, what I want is for a button that I have created in my UICollectionView to call the function (handleNewJob) from the UICollectionViewCell.
Is this possible? I have tried having the function inside the UICollectionView but I can't seem to reference all the textfields.text?
Here is my function inside UICollectionViewCell (I haven't included all the textfield generation as it's quite long):
// HANDLE NEW JOB
func handleNewJob(){
let newJobBrand = jobBrand.text!
let newJobName = jobName.text!
let newDirectorName = directorName.text!
let newAgencyName = agencyName.text!
let newProdCoName = prodCoName.text!
// WHERE TO PUT IN DATABASE
let reference = Database.database().reference().child("jobInfo")
let childRef = reference.childByAutoId()
// REFERENCING DICTIONARY
let jobBrandValue = ["jobBrand": newJobBrand]
let jobNameValue = ["jobName": newJobName]
let jobDirectorValue = ["directorName": newDirectorName]
let jobAgencyNameValue = ["agencyName": newAgencyName]
let jobProdCoValue = ["prodCoName": newProdCoName]
// WRITE TO DATABASE
childRef.updateChildValues(jobBrandValue)
childRef.updateChildValues(jobNameValue)
childRef.updateChildValues(jobDirectorValue)
childRef.updateChildValues(jobAgencyNameValue)
childRef.updateChildValues(jobProdCoValue)
}
Here is my code for the UICollectionView - I want to call the function under the handleNext button:
import UIKit
import Firebase
class page_newJobSwipingController : UICollectionViewController, UICollectionViewDelegateFlowLayout, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
// VARIABLES
var ref:DatabaseReference?
// BOTTOM BUTTONS
private let previousButton: UIButton = {
let button = UIButton(type: .system)
button.setTitle("Previous", for: .normal)
button.titleLabel?.font = UIFont.boldSystemFont(ofSize: 14)
button.setTitleColor(.gray, for: .normal)
button.addTarget(self, action: #selector(handlePrev), for: .touchUpInside)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
private let nextButton: UIButton = {
let button = UIButton(type: .system)
button.setTitle("Next", for: .normal)
button.titleLabel?.font = UIFont.boldSystemFont(ofSize: 14)
let pinkColour = UIColor(red: 232/255, green: 68/266, blue: 133/255, alpha: 1)
button.setTitleColor(.mainPink, for: .normal)
button.translatesAutoresizingMaskIntoConstraints = false
button.addTarget(self, action: #selector(handleNext), for: .touchUpInside)
return button
}()
// SET UP NEXT AND PREVIOUS BUTTONS TO HAVE A FUNCTION
#IBAction func handlePrev(sender : UIButton) {
let prevIndex = max(pageControl.currentPage - 1, 0)
pageControl.currentPage = prevIndex
let indexPath = IndexPath(item: prevIndex, section: 0)
collectionView?.scrollToItem(at: indexPath, at: .centeredHorizontally, animated: true)
}
#IBAction func handleNext(sender : UIButton) {
let nextIndex = pageControl.currentPage + 1
pageControl.currentPage = nextIndex
if nextIndex == 1 {
print ("move to page 2")
} else {
print ("send alert message")
newJobCellGeneral.handleNewJob()
storyboardAlert()
}
let indexPath = IndexPath(item: 1, section: 0)
collectionView?.scrollToItem(at: indexPath, at: .centeredHorizontally, animated: true)
}
// HANDLE UPLOAD STORYBOARD OPTIONS
#IBAction func storyboardAlert() {
let imagePickerController = UIImagePickerController()
imagePickerController.delegate = self
// ACTION SHEET FOR ADDING NEW ATTACHMENT
let alert = UIAlertController(title: "Job Created", message: "Do you want to upload storyboard cells now?", preferredStyle: .actionSheet)
alert.addAction(UIAlertAction(title: "Now", style: .default, handler: { (action:UIAlertAction) in
let storyboardUpload = page_newJobStoryboardUpload()
self.show(storyboardUpload, sender: self)
}))
alert.addAction(UIAlertAction(title: "Later", style: .default, handler: { (action:UIAlertAction) in
let jobList = page_jobList()
self.show(jobList, sender: self)
}))
alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
self.present(alert, animated: true, completion: nil)
}
// PAGE CONTROL
private let pageControl: UIPageControl = {
let pc = UIPageControl()
pc.numberOfPages = 2
pc.currentPageIndicatorTintColor = .mainPink
pc.pageIndicatorTintColor = UIColor(red: 249/255, green: 207/266, blue: 224/255, alpha: 1)
return pc
}()
override func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
let x = targetContentOffset.pointee.x
pageControl.currentPage = Int(x / view.frame.width)
}
// CONSTRAINTS OF BOTTOM CONTROLS
fileprivate func setupBottomControls(){
let bottomControlsStackView = UIStackView(arrangedSubviews: [previousButton, pageControl, nextButton])
bottomControlsStackView.translatesAutoresizingMaskIntoConstraints = false
bottomControlsStackView.distribution = .fillEqually
view.addSubview(bottomControlsStackView)
NSLayoutConstraint.activate([
bottomControlsStackView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor),
bottomControlsStackView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
bottomControlsStackView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
bottomControlsStackView.heightAnchor.constraint(equalToConstant: 50)
])
}
// SUPER VIEW DID LOAD
override func viewDidLoad() {
super.viewDidLoad()
collectionView?.backgroundColor = .white
collectionView?.register(newJobCellGeneral.self, forCellWithReuseIdentifier: "newJobCellGeneral")
collectionView?.register(newJobCellTechnical.self, forCellWithReuseIdentifier: "newJobCellTechnical")
collectionView?.isPagingEnabled = true
setupBottomControls()
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 0
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 2
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
if indexPath.item == 0 {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "newJobCellGeneral", for: indexPath) as! newJobCellGeneral
navigationItem.title = "General Info"
return cell
} else {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "newJobCellTechnical", for: indexPath) as! newJobCellTechnical
navigationItem.title = "Technical Specs"
return cell
}
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: view.frame.width, height: view.frame.height)
}
}

Answer 1

The flow is inversed but yes, the easiest way is via notifications
in you collection view
Put this in your collectionView button pressed method
NotificationCenter.default.post(name: Notification.Name("handleNewJob"), object: nil)
Add observer in you collection view cell (init or awakeFromNib depends)
NotificationCenter.default.addObserver(self, selector: #selector(handleNewJob, name: NSNotification.Name(rawValue: "handleNewJob"), object: nil)

Answer 2

Notification Center is one solution, but the easier way is to be able to call a function on your collection view controller directly from the cell.
To do that, you need to be able to reference your parent view controller. so add this UIView extension:
Create a swift file named UIView.swift and paste this:
import UIKit
extension UIView {
var parentViewController: UIViewController? {
var parentResponder: UIResponder? = self
while parentResponder != nil {
parentResponder = parentResponder!.next
if parentResponder is UIViewController {
return parentResponder as! UIViewController!
}
}
return nil
}
}
then from your cell, for example when a button is clicked:
#IBAction func someButtonAction(sender : UIButton) {
let parent = self.parentViewController as! page_newJobSwipingController
parent.whateverFunction()
}