Update array Object and display it in collectionView - ios

Question

I have a list of machine name and type in tableView and when user click it, it push into detailVC.
At first the the user don't have an image, than user choose an image from gallery and return it as a PHAssets.
Than I convert the PHAssets into data and show it in collectionView, so I create an array of data and display it in collectionView.
Than I want to update MachineItem object to my data from PHAssets, since in MachineItem object have an array of Data.
So when user return from machine list in tableView, the object already update. But when I tap the list from tableView. The photo I save in an object is not showing, how can display it in my collectionView.
This is my Model
struct MachineItem: Codable {
var id = UUID().uuidString
var name: String
var type: String
var qrNumber = Int.random(in: 1..<10)
var maintenanceDate: String?
var images: [Data]?
}
This is my MachineStore class that perform all add, update, and remove object from MachineItem
class MachineStore {
var items: [MachineItem] = []
#discardableResult func add(_ machine: MachineItem, at index: Int) -> MachineItem {
let newMachine = MachineItem(id: machine.id, name: machine.name, type: machine.type, qrNumber: machine.qrNumber, maintenanceDate: machine.maintenanceDate, images: machine.images)
items.insert(newMachine, at: index)
return newMachine
}
func update(_ machine: MachineItem) {
if let index = items.firstIndex(where: { $0.id == machine.id }) {
items[index].name = machine.name
items[index].type = machine.type
items[index].qrNumber = machine.qrNumber
items[index].maintenanceDate = machine.maintenanceDate
items[index].images = machine.images
}
}
#discardableResult func remove(at index: Int) -> MachineItem {
return items.remove(at: index)
}
}
This is my MachineDataVC that have a list of MachineItem Object in TableView
class MachineDataVC: UIViewController {
var tableView = UITableView()
var store = MachineStore()
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let item = store.items[indexPath.row]
let detailVC = MachineDetailVC()
detailVC.item = item
detailVC.store = store
navigationController?.pushViewController(detailVC, animated: true)
tableView.deselectRow(at: indexPath, animated: true)
}
}
And this is the detailVC where I can't display the images data when back and fort from MachineDataVC to detailVC
class MachineDetailVC: UIViewController {
var item: MachineItem!
var store: MachineStore!
var images: [Data] = []
var photoCollectionView = UICollectionView(frame: .zero, collectionViewLayout: UICollectionViewFlowLayout())
override func viewDidLoad() {
super.viewDidLoad()
// CollectionView setup
photoCollectionView.delegate = self
photoCollectionView.dataSource = self
photoCollectionView.register(MachineDetailCell.self, forCellWithReuseIdentifier: MachineDetailCell.cellID)
photoCollectionView.backgroundColor = .systemBackground
}
// This where PHAssets being retrieve
#objc func pickPhotos() {
let imagePickerVC = ImagePickerController()
imagePickerVC.settings.selection.max = 10
imagePickerVC.settings.theme.selectionStyle = .numbered
imagePickerVC.settings.fetch.assets.supportedMediaTypes = [.image]
imagePickerVC.settings.selection.unselectOnReachingMax = true
self.presentImagePicker(imagePickerVC) { (assets) in
} deselect: { (_) in
} cancel: { (_) in
} finish: { (assets) in
self.images = self.getImage(from: assets)
self.photoCollectionView.reloadData()
}
}
private func getImage(from assets: [PHAsset]) -> [Data] {
let images = assets.map { fetchImage(from: $0) }
print("Pick image:", images)
return images
}
private func fetchImage(from asset: PHAsset) -> Data {
let manager = PHImageManager.default()
let options = PHImageRequestOptions()
options.isSynchronous = true
var thumbnail = Data()
manager.requestImage(for: asset, targetSize: .init(width: 100, height: 100), contentMode: .aspectFill, options: options) { (result, info) in
if let selectedImage = result?.data {
thumbnail = selectedImage
}
}
return thumbnail
}
// This is how I setup collectionView
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return images.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: MachineDetailCell.cellID, for: indexPath) as! MachineDetailCell
let image = images[indexPath.row]
cell.set(imageData: image)
return cell
}
// This is how I save the object from UIBarButtonItem
#objc func saveItem() {
guard let name = machineNameTF.text else { return }
guard let type = machineTypeTF.text else { return }
guard let date = machineMaintenanceDateTF.text else { return }
let machineItem = MachineItem(id: item.id, name: name, type: type, qrNumber: item.qrNumber, maintenanceDate: date, images: images)
store.update(machineItem)
}
}
What I've been trying so far is like this
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
if !images.isEmpty {
return store.items.count
} else {
return images.count
}
}
I'm very glad if anyone can help me :)

Answer 1

I finally found my answer from my question, what I need to do is in my viewDidLoad I need to add in my MachineDetailVC
self.images = self.item.images ?? []
since when I save the data back into items in machineStore, I need to give the data into images array in MachineDetailVC