I am trying to create a program which dynamically updates the collectoinView as the user enters text into the UITextField. Below is the extension I have created to achieve this
I have updated code based on your suggestions to include insert and delete statements,I am still in the process of refactoring and adding delegation but while the code doesn't result in an error it doesn't allow the user to keep typing and closes the keyboard have I implemented everything correctly
Update #2 (Thank you for all of your Help)
import UIKit
class ViewController: UIViewController, UICollectionViewDelegateFlowLayout, UICollectionViewDataSource, UICollectionViewDelegate, UISearchBarDelegate {
lazy var collectionView : UICollectionView = {
let layout = UICollectionViewFlowLayout()
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.backgroundColor = .white
cv.delegate = self
cv.dataSource = self
return cv
}()
var genericTagsArray:[String] = ["tag1","tag2","tag3","tag4","tag5","tag6","tag7","tag8","tag9","tag10","tag11","tag12","A","B","C","D","E","F","G","Ab","Abc","za","tag1","tag2","tag3","tag4","tag5","tag6","tag7","tag8","tag9","tag10","tag11","tag12","A","B","C","D","E","F","G","Ab","Abc","za"]
var currentTagsArray:[String] = [String]() {
didSet {
collectionView.reloadData()
}
}
override func viewDidLoad() {
super.viewDidLoad()
self.view.addSubview(collectionView)
collectionView.register(Cell.self, forCellWithReuseIdentifier: "cell")
collectionView.register(Header.self, forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "header")
collectionView.anchor(top: view.safeAreaLayoutGuide.topAnchor, leading: self.view.leadingAnchor, bottom: self.view.bottomAnchor, trailing: self.view.trailingAnchor, padding: .init(top: 30, left: 0, bottom: 30, right: 0))
collectionView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0)
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return currentTagsArray.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! Cell
cell.label.text = currentTagsArray[indexPath.item]
return cell
}
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
let header = collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "header", for: indexPath) as! Header
header.searchBar.delegate = self
return header
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
return CGSize(width: collectionView.contentSize.width, height: 75)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: self.view.frame.size.width, height: 50)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return 5
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 5
}
func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
self.currentTagsArray = self.genericTagsArray.filter { (text) -> Bool in
return text.contains(searchText.lowercased())
}
}
}
class Cell : UICollectionViewCell {
let label = UILabel()
override init(frame: CGRect) {
super.init(frame: frame)
setupViews()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func setupViews() {
self.backgroundColor = .gray
self.addSubview(label)
label.anchor(top: self.topAnchor, leading: self.leadingAnchor, bottom: self.bottomAnchor, trailing: self.trailingAnchor)
}
}
class Header: UICollectionReusableView{
var searchBar = UISearchBar(frame: .zero)
override init(frame: CGRect) {
super.init(frame: frame)
setupViews()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func setupViews() {
self.backgroundColor = .gray
self.addSubview(searchBar)
searchBar.anchor(top: self.topAnchor, leading: self.leadingAnchor, bottom: nil, trailing: self.trailingAnchor, padding: .init(top: 0, left: 5, bottom: 0, right: 5), size: .init(width: 0, height: 50))
}
}
extension UIView {
func anchor(top: NSLayoutYAxisAnchor?, leading: NSLayoutXAxisAnchor?, bottom: NSLayoutYAxisAnchor?, trailing: NSLayoutXAxisAnchor?, padding: UIEdgeInsets = .zero, size: CGSize = .zero) {
translatesAutoresizingMaskIntoConstraints = false
if let top = top {
topAnchor.constraint(equalTo: top, constant: padding.top).isActive = true
}
if let leading = leading {
leadingAnchor.constraint(equalTo: leading, constant: padding.left).isActive = true
}
if let bottom = bottom {
bottomAnchor.constraint(equalTo: bottom, constant: -padding.bottom).isActive = true
}
if let trailing = trailing {
trailingAnchor.constraint(equalTo: trailing, constant: -padding.right).isActive = true
}
if size.width != 0 {
widthAnchor.constraint(equalToConstant: size.width).isActive = true
}
if size.height != 0 {
heightAnchor.constraint(equalToConstant: size.height).isActive = true
}
}
}
Updated Function With Edits
@objc func textFieldDidChange(){
guard(!(feedSearchBar.text?.isEmpty)!) else{
VC.currentTagsArray = VC.genericTagsArray
VC.feedScreenCollectionView.reloadData()
return
}
VC.currentTagsArray = VC.genericTagsArray.filter({letter -> Bool in
if feedSearchBar.text!.count > letter.count{
return false
}
let stringRange = letter.index(letter.startIndex, offsetBy: feedSearchBar.text!.count)
let subword = letter[..<stringRange]
return subword.lowercased().contains(feedSearchBar.text!.lowercased())
})
if VC.currentTagsArray.isEmpty{
VC.feedScreenCollectionView.deleteItems()
VC.currentTagsArray.insert(feedSearchBar.text!, at: 0)
VC.feedScreenCollectionView.insertItems(at: [IndexPath(item: 0, section: 0)])
//VC.feedScreenCollectionView.reloadItems(inSection: 0)
// VC.feedScreenCollectionView.reloadItems(at: [IndexPath(item: 0, section: 0)])
}
//VC.feedScreenCollectionView.reloadData()
VC.feedScreenCollectionView.reloadItems(inSection: 0)
}
extension UICollectionView{
func reloadItems(inSection section:Int = 0) {
var indicies:[IndexPath] = [IndexPath]()
print("current number of items to reload \(self.numberOfItems(inSection: section))")
for i in 0..<self.numberOfItems(inSection: section){
indicies.append(IndexPath(item: i, section: section))
print("current item number: \(i)")
}
self.reloadItems(at: indicies)
// self.insertItems(at: indicies)
}
func deleteItems(inSection section:Int = 0){
var indicies:[IndexPath] = [IndexPath]()
for i in 0..<self.numberOfItems(inSection: section){
indicies.append(IndexPath(item: i, section: section))
}
self.deleteItems(at: indicies)
}
}
Original Function:
extension UICollectionView{
func reloadItems(inSection section:Int = 0) {
var indicies:[IndexPath] = [IndexPath]()
for i in 0..<self.numberOfItems(inSection: section){
indicies.append(IndexPath(item: i, section: section))
}
self.reloadItems(at: indicies)
}
}
However when ever I call this function after the textField has been edited the program crashes with the error
* Assertion failure in -[UICollectionView _endItemAnimationsWithInvalidationContext:tentativelyForReordering:animator:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKit_Sim/UIKit-3698.54.4/UICollectionView.m:5867 2018-07-18 16:28:02.226606-0400 FeedScreenReuseableView[87752:9704142] * Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'attempt to insert item 6 into section 0, but there are only 6 items in section 0 after the update'
I am not sure how to fix this. Is there a better way to go about reloading cells that does not affect the header. Thank you for all of your help in advance. Below is the code from the project in its entirety.
import UIKit
class ViewController: UIViewController,UICollectionViewDelegateFlowLayout,UICollectionViewDelegate,UICollectionViewDataSource,printDelegateWorkedDelegate,updateCollectionView{
func updateCollectionView() {
self.feedScreenCollectionView.reloadData()
}
func printDelegateWorkedDelegate() {
print("The delegate worked")
}
var genericTagsArray:[String] = ["tag1","tag2","tag3","tag4","tag5","tag6","tag7","tag8","tag9","tag10","tag11","tag12","A","B","C","D","E","F","G","Ab","Abc","za","tag1","tag2","tag3","tag4","tag5","tag6","tag7","tag8","tag9","tag10","tag11","tag12","A","B","C","D","E","F","G","Ab","Abc","za"]
var currentTagsArray:[String] = [String]()
var tagsSelected:[String] = [String]()
let keyboardSlider = KeyboardSlider()
var header:feedViewHeader = feedViewHeader()
@IBOutlet weak var feedScreenCollectionView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
keyboardSlider.subscribeToKeyboardNotifications(view: view)
currentTagsArray = genericTagsArray
let viewTapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(feedViewHeader.viewTapped(gestureRecognizer:)))
viewTapGestureRecognizer.cancelsTouchesInView = false
self.feedScreenCollectionView.addGestureRecognizer(viewTapGestureRecognizer)
feedScreenCollectionView.delegate = self
//
feedScreenCollectionView.dataSource = self
//
let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 5, left: 1, bottom: 0, right: 1)
layout.minimumLineSpacing = 0
layout.headerReferenceSize = CGSize(width: 50, height: 75)
layout.sectionHeadersPinToVisibleBounds = true
feedScreenCollectionView.collectionViewLayout = layout
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
return CGSize(width: 50, height: 75)
}
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
header = collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "feedViewHeader", for: indexPath) as! feedViewHeader
header.VC = self
return header
}
//
//Data Source
func numberOfSections(in collectionView: UICollectionView) -> Int {
return 1
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return currentTagsArray.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "feedViewCell", for: indexPath) as! feedViewCell
cell.feedImageView.backgroundColor = .blue
cell.feedImageView.clipsToBounds = true
cell.feedImageView.layer.cornerRadius = CGFloat((cell.feedImageView.frame.width)/5)
cell.feedLabel.text = currentTagsArray[indexPath.item]
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 0
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat{
return 0
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let collectionViewWidth = collectionView.bounds.width/4.0
let collectionViewHeight = collectionViewWidth
return CGSize(width: collectionViewWidth-4, height: collectionViewHeight+25)
}
var lastContentOffset:CGFloat = 0
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if self.lastContentOffset > self.feedScreenCollectionView.contentOffset.y && self.feedScreenCollectionView.contentOffset.y > 0 && self.feedScreenCollectionView.contentOffset.y < self.feedScreenCollectionView.frame.maxY {
self.lastContentOffset = scrollView.contentOffset.y
header.isHidden = false
}
else if (self.lastContentOffset < self.feedScreenCollectionView.contentOffset.y) && (self.feedScreenCollectionView.contentOffset.y < self.feedScreenCollectionView.frame.maxY) && (self.feedScreenCollectionView.contentOffset.y > 0) {
print("you scrolled down,content offSet: \(scrollView.contentOffset.y)->\(self.feedScreenCollectionView.contentOffset.y)")
header.isHidden = true
}
else{
self.lastContentOffset = scrollView.contentOffset.y
print("content offSet: \(scrollView.contentOffset.y)")
print("Nothing happened")
// self.headerDelegate?.hideHeaderView(hide: true)
}
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardFrameChangeNotification(notification:)), name: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil)
}
var offsetY:CGFloat = 0
@objc func keyboardFrameChangeNotification(notification: Notification) {
}
}
class feedViewCell:UICollectionViewCell{
@IBOutlet weak var feedImageView: UIImageView!
@IBOutlet weak var feedLabel: UILabel!
let keyboardSlider = KeyboardSlider()
override func awakeFromNib() {
super.awakeFromNib()
feedLabel.translatesAutoresizingMaskIntoConstraints = false
feedImageView.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
feedImageView.leadingAnchor.constraint(equalTo: self.leadingAnchor).isActive = true
feedImageView.trailingAnchor.constraint(equalTo: self.trailingAnchor).isActive = true
feedImageView.bottomAnchor.constraint(equalTo: self.feedLabel.topAnchor).isActive = true
feedImageView.translatesAutoresizingMaskIntoConstraints = false
feedLabel.leadingAnchor.constraint(equalTo: self.leadingAnchor).isActive = true
feedLabel.trailingAnchor.constraint(equalTo: self.trailingAnchor).isActive = true
feedLabel.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
feedLabel.topAnchor.constraint(equalTo: self.feedImageView.bottomAnchor).isActive = true
feedLabel.textAlignment = .center
}
}
class feedViewHeader:UICollectionReusableView,UITextFieldDelegate,UICollectionViewDelegate{
@IBOutlet weak var feedSearchBar: UITextField!
var delegateWorked:printDelegateWorkedDelegate?
var updateCV:updateCollectionView?
var VC:ViewController!
var collectionView:UICollectionView?
var stringToBeSet = "String to be set"
override func awakeFromNib() {
super.awakeFromNib()
feedSearchBar.delegate = self
feedSearchBar.autocorrectionType = .no
feedSearchBar.keyboardType = .default
feedSearchBar.addTarget(self, action: #selector(feedViewHeader.textFieldDidChange), for: .editingChanged)
self.feedSearchBar.borderStyle = .roundedRect
self.feedSearchBar.layer.borderColor = UIColor.black.cgColor
self.feedSearchBar.layer.borderWidth = 4
var searchBarHeight = self.feedSearchBar.bounds.height
self.feedSearchBar.placeholder = "Tap To Search"
self.feedSearchBar.returnKeyType = .search
self.feedSearchBar.rightViewMode = .always
}
@objc func viewTapped(gestureRecognizer:UIGestureRecognizer){
if feedSearchBar.isFirstResponder{
feedSearchBar.resignFirstResponder()
}
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
textField.resignFirstResponder()
VC.feedScreenCollectionView.reloadData()
//VC.feedScreenCollectionView.reloadSections([0])
return true
}
/// Helper to dismiss keyboard
@objc func didStopEditing() {
}
func textFieldDidEndEditing(_ textField: UITextField) {
UIView.setAnimationCurve(UIViewAnimationCurve.easeInOut)
UIView.animate(withDuration: 0.2) {
self.VC.view.frame.origin.y = 0
}
}
@objc func textFieldDidChange(){
guard(!(feedSearchBar.text?.isEmpty)!) else{
VC.currentTagsArray = VC.genericTagsArray
VC.feedScreenCollectionView.reloadData()
return
}
VC.currentTagsArray = VC.genericTagsArray.filter({letter -> Bool in
if feedSearchBar.text!.count > letter.count{
return false
}
let stringRange = letter.index(letter.startIndex, offsetBy: feedSearchBar.text!.count)
let subword = letter[..<stringRange]
return subword.lowercased().contains(feedSearchBar.text!.lowercased())
})
if VC.currentTagsArray.isEmpty{
VC.currentTagsArray.insert(feedSearchBar.text!, at: 0)
}
VC.feedScreenCollectionView.reloadItems(inSection: 0)
}
}
extension Notification.Name{
static let showKeyboard = Notification.Name("showKeyboard")
}
class KeyboardSlider: NSObject {
// variables to hold and process information from the view using this class
weak var view: UIView?
@objc func keyboardWillShow(notification: NSNotification) {
// method to move keyboard up
// view?.frame.origin.y = 0 - getKeyboardHeight(notification as Notification)
print("made it to keyboard will show")
}
func getKeyboardHeight(_ notification:Notification) -> CGFloat {
// get exact height of keyboard on all devices and convert to float value to return for use
let userInfo = notification.userInfo
let keyboardSize = userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue
return keyboardSize.cgRectValue.height
}
func subscribeToKeyboardNotifications(view: UIView) {
// assigning view to class' counterpart
self.view = view
// when UIKeyboardWillShow do keyboardWillShow function
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: .UIKeyboardWillShow, object: nil)
}
func unsubscribeFromKeyboardNotifications() {
NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillShow, object: nil)
}
}
class blankView:UICollectionReusableView{
}
extension UICollectionView{
func reloadItems(inSection section:Int = 0) {
print("made it to reload")
for i in 0..<self.numberOfItems(inSection: section){
self.reloadItems(at: [IndexPath(item: i, section: section)])
}
}
}
