I am working on a meme generator app. The meme generator is presented modally and is built into a tab bar view controller. The first tab displays all saved memes in a table view and the second is intended to display the saved memes in a collection view. The meme generator works as design and is saving generated memes to an array that is located in the App Delegate file (I know this is controversial, but it is a requirement of the exercise). I am attempting to set up the collection view and I am not able to get a reference to the meme object in the app delegate file and I don't understand why.
import UIKit
class CollectionViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource {
#IBOutlet weak var collectionView: UICollectionView!
var memes: [Meme]! {
didSet {
collectionView.reloadData()
}
}
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
let appDelegate = UIApplication.shared.delegate as! AppDelegate
memes = appDelegate.memes
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return memes.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath)
cell.imageView.image = memes[indexPath].memedImage
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
}
}
I based this code on the code used for my table view, which works as designed. That code is:
import UIKit
class TableViewMemesViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet weak var tableView: UITableView!
var memes: [Meme]! {
didSet {
tableView.reloadData()
}
}
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
let appDelegate = UIApplication.shared.delegate as! AppDelegate
memes = appDelegate.memes
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return memes.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell")
let meme = memes[indexPath.row]
cell?.imageView?.image = meme.memedImage
cell?.textLabel?.text = meme.topText
return cell!
}
}
How can I get a reference to the array data and display it inside of the collection view when the user saves a new meme? Here is a link to the repo.
You have some issues, first you have to create a Custom CollectionViewCell:
class Cell: UICollectionViewCell {
#IBOutlet var imageView:UIImageView!
}
remember to set the Custom Class for UICollectionViewCell inside the storyboard:
then when you dequeue the cell, be sure of as! Cell:
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath) as! Cell
cell.imageView.image = memes[indexPath.row].memedImage
return cell
}
Then inside your TabBarStoryboard.storyboard, you must set delegate and datasource for your CollectionViewController (I checked your github, you didn't attach them).
Finally the result will be:
Related
There is a very similar question here, but the solution doesn't solve anything for me, mainly because my embedded collection view is already inside the table view cell's content view (I created it in storyboard).
Is there some setting that I need to check to allow my collection view to scroll? It seems that the parent table view cell is eating up all gestures.
TableViewController.swift
class TableViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, UICollectionViewDataSource, UICollectionViewDelegate {
#IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
tableView.delegate = self
tableView.dataSource = self
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! CustomTableViewCell
cell.collectionView.dataSource = self
cell.collectionView.delegate = self
return cell
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 5
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionCell", for: indexPath)
return cell
}
}
CustomTableViewCell.swift
class CustomTableViewCell: UITableViewCell {
#IBOutlet weak var collectionView: UICollectionView!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
You can find my demo project here
https://github.com/MattiaPell/CollectionView-inside-a-TableViewCell
Turns out in my case it was simple as not having User Interaction Enabled check marked for my child collection view.
I am attempting to set a CollectionView inside of a TableViewCell. I have read through a hand full of stack questions, tuts, and videos and so far I have what appears to be the correct method but my collection view is still not loading into my table view cell.
Code:
import UIKit
class TheaterCell: UITableViewCell {
#IBOutlet var theaterName: UILabel!
#IBOutlet var theaterLocation: UILabel!
#IBOutlet var showtimesCollection: UICollectionView!
override func awakeFromNib() {
super.awakeFromNib()
showtimesCollection.delegate = self
showtimesCollection.dataSource = self
showtimesCollection.reloadData()
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
extension TheaterCell: UICollectionViewDataSource, UICollectionViewDelegate {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 10
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = showtimesCollection.dequeueReusableCell(withReuseIdentifier: "timeCell", for: indexPath) as! TimeCell
cell.time.text = "1:00"
return cell
}
}
The Tableview loads from the ViewController and is displaying its cells and elements but the collection view is not loading within the cell.
This is working for me, I think the problems comes from the way you register your cell
class YourCell: UITableViewCell, UICollectionViewDelegate, UICollectionViewDataSource {
#IBOutlet weak var collectionView: UICollectionView!
override func awakeFromNib() {
super.awakeFromNib()
registerCell()
self.collectionView.delegate = self
self.collectionView.dataSource = self
}
func registerCell() {
collectionView.register(TimeCell.self, forCellWithReuseIdentifier: "cell")
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 10
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! TimeCell
cell.time.text = "1:00"
return cell
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
What I do, I use storyboard and setting the delegates & datasource from Storyboard by dragging into the classes.
a) Set TableView's delegates & datasource to ViewController
b) Set CollectionView's delegates & datasource to TableViewCell(TheaterCell)
ViewController Code:
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
}
extension ViewController:UITableViewDelegate, UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let theaterCell:TheaterCell = tableView.dequeueReusableCell(withIdentifier: "TheaterCell", for: indexPath) as! TheaterCell
theaterCell.reloadCollectionView()
return theaterCell
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 200
}
}
TheaterCell Code:
class TheaterCell: UITableViewCell {
#IBOutlet var showtimesCollection: UICollectionView!
override func awakeFromNib() {
super.awakeFromNib()
}
func reloadCollectionView() -> Void {
self.showtimesCollection.reloadData()
}
}
extension TheaterCell: UICollectionViewDataSource, UICollectionViewDelegate {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 10
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = showtimesCollection.dequeueReusableCell(withReuseIdentifier: "timeCell", for: indexPath) as! TimeCell
cell.time.text = "1:00"
return cell
}
}
TimeCell Code:
class TimeCell: UICollectionViewCell {
#IBOutlet var time: UILabel!
}
Here is the output:
NOTE: IF YOU ARE NOT USING STORYBOARDS AND YOU MAKE COLLECTIONVIEW OR TABLE FROM CODE ONLY, THEN YOU HAVE REGISTER YOURS CELL AS:
A) TheaterCell must be registered into ViewController class
B) TimeCell must be registered into TheaterCell class
I have a collection view nested in a table view. The collection view cells are not loading. I am not able to set the collection view delgate and dataSource in the tableViewCell init function because it unwraps as nil, so i created a load function that is called to set it when the cell loads. The issue I have now is that the dataSource/delgate functions are not being called and the table view cell is not loading. My collection view cell for now is just an image, so didn't include that. Also, I have checked that all these outlets are connected correctly, and the table view cell and collection view cell both have reuse identifies set through interface builder. Here is my code:
View Controller:
#IBOutlet weak var libraryTableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
self.libraryTableView.dataSource = self
self.libraryTableView.delegate = self
// Do any additional setup after loading the view.
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
guard let cell = tableView.dequeueReusableCell(withIdentifier: "LibraryTableViewCell", for: indexPath) as? LibraryTableViewCell else {
return LibraryTableViewCell()
}
cell.load()
return cell
}
Table View Cell:
#IBOutlet weak var carouselLabel: UILabel!
#IBOutlet weak var carousel: UICollectionView!
func load() {
layer.backgroundColor = UIColor.clear.cgColor
carouselLabel.text = "hello world"
carousel.delegate = self
carousel.dataSource = self
//carousel.reloadData()
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 1
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
guard let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "packCell", for: indexPath) as? PackCollectionViewCell else {
return PackCollectionViewCell()
}
return cell
}
I have a tableview cell inside which i have added collectionview cell ( for horizontal scrolling).
Now i want to push to other navigation controller on pressing any cell of horizontal collectionview. How to do it ? Or how can i define delegate methods for cell press.
Code :
ViewController.swift :
class ViewController: UIViewController {
var categories = ["Action", "Drama", "Science Fiction", "Kids", "Horror"]
}
extension ViewController : UITableViewDelegate { }
extension ViewController : UITableViewDataSource {
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return categories[section]
}
func numberOfSections(in tableView: UITableView) -> Int {
return categories.count
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell") as! CategoryRow
return cell
}
}
CategoryRow.swift
class CategoryRow : UITableViewCell {
#IBOutlet weak var collectionView: UICollectionView!
}
extension CategoryRow : UICollectionViewDataSource {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 12
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "videoCell", for: indexPath) as! VideoCell
return cell
}
}
extension CategoryRow : UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let itemsPerRow:CGFloat = 4
let hardCodedPadding:CGFloat = 5
let itemWidth = (collectionView.bounds.width / itemsPerRow) - hardCodedPadding
let itemHeight = collectionView.bounds.height - (2 * hardCodedPadding)
return CGSize(width: itemWidth, height: itemHeight)
}
}
VideoCell.swift
class VideoCell : UICollectionViewCell {
#IBOutlet weak var imageView: UIImageView!
}
Here you will get the cell click at the delegate method didSelectItemAtIndexPath on CategoryRow class and from there you can fire a delegate to get call inside ViewController
ViewController.swift :
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell") as! CategoryRow
cell.delegate = self
return cell
}
VideoCell.swift :
protocol CategoryRowDelegate:class {
func cellTapped()
}
CategoryRow.swift :
class CategoryRow : UITableViewCell {
weak var delegate:CategoryRowDelegate?
#IBOutlet weak var collectionView: UICollectionView!
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if delegate!= nil {
delegate?.cellTapped()
}
}
Add the delegate function inside ViewController
func cellTapped(){
//code for navigation
}
First create protocol for delegation from CategoryRow.swift like below code
protocol CollectionViewSelectionDelegate: class {
func didSelectedCollectionViewItem(selectedObject: AnyObject)
}
Now create delegate object on VideoCell.swift like below
weak var delegate:CollectionViewSelectionDelegate?
Change ViewController.swift code before return cell
cell?.delegate = self
Override method of delegate in ViewController.swift and call similar method from VideoCell.swift from UICollectionView Delegate method.
I think its better to use Notification in this case.
post a notification in didSelectItem of collection view
NSNotificationCenter.defaultCenter().postNotificationName(notificationIdentifier, object: nil)
and add an observer in viewController viewDidLoad as follows
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(pushToNew(_:)), name: notificationIdentifier, object: nil)
in the new pushToNew function, perform your segue
func pushToNew(notification: Notification) {
// perform your segue here. Navigate to next view controller
}
Make a protocol
protocol collectionViewCellClicked{
func cellClicked()
}
Implement this protocol in main View Controller Your View Controller look like this
class ViewController: UITableViewController, collectionViewCellClicked{ func cellClicked(){ // Your Code }}
Your cellForRowAt delegate look like this
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: <#T##String#>, for: <#T##IndexPath#>)
cell.delegate = self
return cell
}
In your Table View Cell Make a variable of type collectionViewCellClicked
var delegate: collectionViewCellClicked?
and in your didSelectItemAt delegate
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
delegate.cellClicked()
}
I've created a pretty simple test app. It includes a 3 view controllers. The main view controller has a table view, that uses custom cells. The other two view controllers are able to be accessed through the main view controller, each have collection views, and can go back to the main view controller.
Here is the memory issue. Anytime I click on any of the cells from the 3 view controllers, the memory usage increases. I ran the app while using the 'Leaks' profiling template and found no leaks. Also used the 'Allocations' profiling template, checked 2 of the view controllers (recorded the reference counts), and all the stored reference counts under my program were released.
I haven't been able to use the Debug Memory Graph as it keeps crashing Xcode...
Main View Controller
import UIKit
class TableViewController: UITableViewController, UISearchBarDelegate {
#IBOutlet weak var searchForTool: UISearchBar!
#IBOutlet weak var toolTable: UITableView!
var searchActive : Bool = false
var data = [" Alphabetical", " Numerical"]
var identities = ["A", "B"]
override func viewDidLoad() {
super.viewDidLoad()
toolTable.delegate = self
toolTable.dataSource = self
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return data.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! CustomCell
cell.toolLabel.text = data[indexPath.row]
return cell
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let vcName = identities[indexPath.row]
let viewController = storyboard?.instantiateViewController(withIdentifier: vcName)
self.navigationController?.pushViewController(viewController!, animated: true)
}
}
One of the other View Controllers (both identical)
import UIKit
class AlphabeticalViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource {
#IBOutlet weak var collectionView: UICollectionView!
var labelArray = [String]()
var identities = [String]()
override func viewDidLoad() {
super.viewDidLoad()
labelArray = ["Main", "Definitions", "Steps", "References", "Other"]
identities = ["C", "B", "B", "D", "E"]
self.navigationController?.setNavigationBarHidden(true, animated: false)
collectionView.delegate = self
collectionView.dataSource = self
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return labelArray.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath)
let myLabel = cell.viewWithTag(1) as! UILabel
myLabel.text = labelArray[indexPath.row]
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let vcName = identities[indexPath.row]
let viewController = storyboard?.instantiateViewController(withIdentifier: vcName)
self.navigationController?.pushViewController(viewController!, animated: true)
}
}
Custom Cell Class
import UIKit
class CustomCell: UITableViewCell {
#IBOutlet weak var toolLabel: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
I will provide any other images if needed. Any help would be greatly appreciated.
Information I got using the allocation tool.
The commented out code is just a search feature that I don't need atm.
The problem seems to be inside the CustomCell, maybe some resources not deinitialized.
Do you have some code inside awakeFromNib() or setSelected(...)?
You have problem with your tableView and collection view. look at IBOutlets your tableView name is toolTable
#IBOutlet weak var toolTable: UITableView!
but inside your datasource for the tableView you're accessing the wrong tableView
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
// this is the wrong tableView
/*
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! CustomCell
*/
// you should use the tableview which you have declared
let cell = toolTable.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! CustomCell
cell.toolLabel.text = data[indexPath.row]
return cell
}
You have the same problem with your CollectionViewControllers as well.
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
//accessing wrong collectionView
/*
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath)
*/
// here you have to use self because your have named your collectionView the same as collectionView
let cell = self.collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath)
let myLabel = cell.viewWithTag(1) as! UILabel
myLabel.text = labelArray[indexPath.row]
return cell
}
Note: Your TableViewController and CollectionViewController are already Controllers. wondering why you have another tableView and collection view IBOutlets. Use one at a time
Firstly, I want to give credit to #totiG for pointing out that the problem could be with the navigation controller, and he was right.
There are other smaller memory issues, but the biggest by far had to do with my navigation. I kept pushing controllers onto the navigation stack, without popping them.
Here is the code for my final solution.
I replaced:
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let vcName = identities[indexPath.row]
let viewController = storyboard?.instantiateViewController(withIdentifier: vcName)
self.navigationController?.pushViewController(viewController!, animated: true)
}
With:
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if indexPath.row == 0 {
if let navController = self.navigationController {
for controller in navController.viewControllers {
if controller is TableViewController {
navController.popToViewController(controller, animated: true)
}
}
}
} else {
let vcName = identities[indexPath.row]
let viewController = storyboard?.instantiateViewController(withIdentifier: vcName)
self.navigationController?.pushViewController(viewController!, animated: true)
}
}
So now instead of pushing from controller to controller without popping any of them off of the stack, I pop all of the previous controllers up to the 'TableViewController' when 'Main' is clicked.