I am using a UITableView in one of my view controllers and am using a custom class called ListCell. The table view and the cells are being displayed, but the content in the cells are not being displayed, so the cell is empty. But if I press the cell it performs its task. So the content is there but its not being displayed. I think it has something to do with how I registered the class to the custom type ListCell. Here is how I declared it in viewDidLoad...
self.tblListView.registerClass(ListCell.self, forCellReuseIdentifier: "Cell")
Is there something wrong with the above line. And what it is causing the cell content to not being displayed?
Also I tried enabling size classes and that did not work. Also all the cells are being created programmatically.
The below line of code is responsible for displaying the cell data.
cell.displayAlertData(mutArrAlertList.objectAtIndex(indexPath.row) as! [NSObject : AnyObject])
the thing is mutArrAlertList's object at the first index is an optional type Optional(Temperature). I think the only way this will work if it is not optional. The object is being passed my a push notification, and what the push notification sends is not optional. So somewhere it randomly turns into an optional type. Is there a way I can get rid of that optional value around it?
Here is cell for row method:
func tableView (tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cellIdentifier: String = "Cell"
var cell = tableView.dequeueReusableCellWithIdentifier("Cell") as! ListCell
//if cell == nil
//{
//let nib: NSArray = NSBundle.mainBundle().loadNibNamed("ListCell", owner: self, options: nil)
//cell = (nib.objectAtIndex(0) as? ListCell)!
//}
cell.selectionStyle = UITableViewCellSelectionStyle.None
print("")
print("This is cell: \(mutArrAlertList.objectAtIndex(indexPath.row) as! [NSObject : AnyObject])") //did this to check what the value is and it is an optional
cell.displayAlertData(mutArrAlertList.objectAtIndex(indexPath.row) as! [NSObject : AnyObject])
if indexPath.row == mutArrAlertList.count-1
{
if ApplicationDelegate.intPage > mutArrAlertList.count
{
//do nothing
}
else
{
ApplicationDelegate.intPage = ApplicationDelegate.intPage + 10
self.reloadDataFromdb()
}
}
return cell
}
Related
I read similar questions such as how to have multiple collection view in multiple table view cells and I connected my collection views cells and use identifier names for them but I don't know why I receive this Error:
* Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'could not dequeue a view of kind: UICollectionElementKindCell with identifier extera_infoCollectionViewCell - must register a nib or a class for the identifier or connect a prototype cell in a storyboard'
* First throw call stack:
**Remember that I read Similar questions and the first table view cell with collection view working well and the problem is for second one **
here is my code for main view controller that has a table view and the table view has two cells
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
if collectionView == fieldOfActivityCell().fieldofActivitiesCollectionView {
let fullfields : String = self.adv.resultValue[0].work_field!
let fullfieldsArr : [String] = fullfields.components(separatedBy: ",")
print(fullfieldsArr)
return fullfieldsArr.count
} else {
let extera_infofields : String = self.adv.resultValue[0].extera_info!
let extera_infofieldsArr : [String] = extera_infofields.components(separatedBy: ",")
print(extera_infofieldsArr)
return extera_infofieldsArr.count
}
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
if collectionView == fieldOfActivityCell().fieldofActivitiesCollectionView {
let fieldsCells = collectionView.dequeueReusableCell(withReuseIdentifier: "fieldOfActivityCollectionViewCell", for: indexPath) as! fieldOfActivityCollectionViewCell
let fullfields : String = self.adv.resultValue[0].work_field!
let fullfieldsArr : [String] = fullfields.components(separatedBy: ",")
fieldsCells.title.text = fullfieldsArr[indexPath.row]
return fieldsCells
}
else {
let extera_infoCells = collectionView.dequeueReusableCell(withReuseIdentifier: "extera_infoCollectionViewCell", for: indexPath) as! extera_infoCollectionViewCell
let extera_info : String = self.adv.resultValue[0].extera_info!
let extera_infoArr : [String] = extera_info.components(separatedBy: ",")
extera_infoCells.infoText.text = extera_infoArr[indexPath.row]
return extera_infoCells
}
}
and here is the table view codes in same view controller:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.row == 0{
let fieldCell = self.showAdvTableView.dequeueReusableCell(withIdentifier: "fieldOfActivityCell", for: indexPath) as! fieldOfActivityCell
return fieldCell
} else {
let fieldCell = self.showAdvTableView.dequeueReusableCell(withIdentifier: "extera_infoCell", for: indexPath) as! extera_infoCell
return fieldCell
}
here is table view first cell class:
class fieldOfActivityCell: UITableViewCell {
#IBOutlet weak var fieldofActivitiesCollectionView: UICollectionView!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
if let flowLayout = fieldofActivitiesCollectionView.collectionViewLayout as? UICollectionViewFlowLayout { flowLayout.estimatedItemSize = CGSize.init(width: 1.0, height: 1.0) }
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
extension fieldOfActivityCell {
func setCollectionViewDataSourceDelegate
<D: UICollectionViewDelegate & UICollectionViewDataSource>
(_ dataSourceDelegate:D , forRow row : Int )
{
fieldofActivitiesCollectionView.delegate = dataSourceDelegate
fieldofActivitiesCollectionView.dataSource = dataSourceDelegate
fieldofActivitiesCollectionView.reloadData()
}
}
and here is the second tableview cell class:
#IBOutlet weak var extra_infoCollectionView: UICollectionView!
override func awakeFromNib() {
super.awakeFromNib()
if let flowLayout = extra_infoCollectionView.collectionViewLayout as? UICollectionViewFlowLayout { flowLayout.estimatedItemSize = CGSize.init(width: 1.0, height: 1.0) }
}
}
extension extera_infoCell {
func setCollectionViewDataSourceDelegate
<D: UICollectionViewDelegate & UICollectionViewDataSource>
(_ dataSourceDelegate:D , forRow row : Int )
{
extra_infoCollectionView.delegate = dataSourceDelegate
extra_infoCollectionView.dataSource = dataSourceDelegate
extra_infoCollectionView.reloadData()
}
}
First step: using Tags - you just need to use tag for them and use if else to choose which collection view has selected with tag so the answer is this :
if collectionView.tag == 1 {
do some thing//////
}else {
do some thing else}
and you should use this in both cellForRowAtIndexPath and numberOfRows methods you can use this for table view too
Second step: you have to change the name of 'collection view' that you are dequeueing inside the cellForRowAt method in CollectionView data source:
if collectionView.tag == 1 {
let cell = yourFirstCollectionView.dequeueReusableCell(...) as yourCell
....
return cell
} else {
let cell = yourSecondCollectionView.dequeueReusableCell(...) as yourCell
....
return cell
}
According to your error your reuse identifier doesn't match any cell in your storyboard. Click on your extera_info collectionView cell in interface builder. Select the attributes inspector tab. Under reuse identifier make sure you put in extera_infoCollectionViewCell
If you take the other tableview cell In different class , with NSObject features of storyboard it can help you , And it is easy to maintain .
Saeed's tag option above is likely the simplest answer, but found his description a little short so adding a more complete answer below for those who've never used tags before...
If abiding by MVC and placing collectionView dataSource methods inside the UITableView class (instead of inside the UITableViewCell classes), and wanting to avoid this " error:
Each Collection View you use will need its own dequeueReusableCell identifier:
In interface-builder, name all your identifiers for your collection view cells. CatPicCell & DogPicCell for instance.
In your CellForItemAt collectionView method, set up if-statements or switch statement such that each reuse identifier is set equal to the identifiers you created in interface-builder (step 1). If using switch/case, your value can be set to collectionView.tag. Tags can be numbered to identify each different collectionView. The tags are like turning your set of collectionViews into a dictionary or array, such that each collectionView gets its own unique key/index.
Go back into interface-builder, and go into your storyboard and select each collection view (each of which should be inside its own tableView cell). In Xcode's "attribute inspector" scroll down to the "View" section and 3 spaces down (Xcode 11, Swift 5) you'll see a field called "Tag". Assign an integer value to that collection view, and then repeat this process for each collection view which is going to be embedded in your UITableView cells.
Once you have all the collection views tagged with unique integers, you simply set your cases to the integers, and give each dequeueReusableCell identifier the same integer index as you provided in the storyboard.
Now when you tableView cell calls on the collectionView you've outletted in the TableViewCell classes, it will be able to acquire the proper dequeueReusable ID. You can put your data inside each switch case.
Voila, you now have ONE collectionView datasource set of required methods, but serving ALL of your collection views. EVEN BETTER, when someone expands the project and adds another collectionView it will be as easy as adding another case to the switch and identifier in the storyboard.
Example code could look like this:
// I need a switch statement which will set the correct (of the 3 collectionViews) dequeueReusable IDENTIFIER for the collectionView
switch collectionView.tag {
//if tableView is doing cell == 1, then "CatsCell"
//if ... cell == 3, then "DogsCell"
//if ... cell == 5, then "BirdsCell"
case 1:
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CatsCell", for: indexPath) as! CatsCVCell
// put your required data here
return cell
case 3:
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "DogCell", for: indexPath) as! DogsCVCell
// example data
let dogs = dogController.fetch()
cell.name = dogs[indexPath.item].dogName
if let image = UIImage(data: groups[indexPath.item].image!) {
cell.image = image
}
return cell
case 5:
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "BirdCell", for: indexPath) as! BirdCVCell
// put data code here for birds collection view cells
return cell
default:
return UICollectionViewCell() // or write a fatalError()
}
note: you have two options for your default to the switch statement...
1. like above, a generic but empty cell instance
2. throw an error. The error should never throw bc you'll have all the cases, but an error could occur if someone else improves your code and add another collectionView but forgets to to add the switch case-- so make your error statement explain what's wrong precisely.
My TableView features custom Cells which have a button to display corresponding detailed info in another view.
This thread here got me started and I tried to implement the approach with the delegate inside the customCell:
How to access the content of a custom cell in swift using button tag?
What I want to achieve is that when I click on the button it reads the name of the cell and passes it on to the next controller. However it seems that I cannot pass the name with the delegate method and its field is nil.
How can I get the specific content of a cell when clicking on its button?
This is what I did so far:
In the class creating my own cell I set delegate:
protocol CustomCellDelegate {
func cellButtonTapped(cell: DemoCell)
}
(........)
var delegate: CustomCellDelegate?
#IBAction func buttonTapped(sender: AnyObject) {
delegate?.cellButtonTapped(self)
}
In the TableViewController I have the following:
override func tableView(tableView: UITableView, cellForRowAtIndexPath
indexPath: NSIndexPath) -> UITableViewCell {
let cell =
tableView.dequeueReusableCellWithIdentifier("FoldingCell",
forIndexPath: indexPath) as! DemoCell
cell.delegate = self
//TODO: set all custom cell properties here (retrieve JSON and set in cell), use indexPath.row as arraypointer
let resultList = self.items["result"] as! [[String: AnyObject]]
let itemForThisRow = resultList[indexPath.row]
cell.schoolNameClosedCell.text = itemForThisRow["name"] as! String
cell.schoolNameOpenedCell.text = itemForThisRow["name"] as! String
self.schoolIdHelperField = itemForThisRow["name"] as! String
cell.schoolIntroText.text = itemForThisRow["name"] as! String
//call method when button inside cell is tapped
cell.innerCellButton.addTarget(self, action: #selector(MainTableViewController.cellButtonTapped(_:)), forControlEvents: .TouchUpInside)
cell.school_id = itemForThisRow["name"] as! String
// cell.schoolIntroText.text = "We from xx University..."
return cell
}
And finally the target method when the button inside the cell is clicked
func cellButtonTapped(cell: DemoCell) {
print("the school id: ")
print(cell.schoolNameOpenedCell) //this line throws an error EXC_BAD_ACCESS 0x0
}
Firstly, the object innerCellButton is not a Cell, it's a button. The simple way to solve your problem is, just refer the index of the button. Please find the below method.
func cellButtonTapped(AnyObject: sender) {
let resultList = self.items["result"] as! [[String: AnyObject]]
//Get the tag value of the selected button.
//Button tag should be matching with the corresponding cell's indexpath.row
let selectedIndex = sender.tag
let itemForThisRow = resultList[selectedIndex]
print("the school id: \(itemForThisRow[\"name\"])")
}
* And set each button's tag as indexPath.row *
E.g.,
override func tableView(tableView: UITableView, cellForRowAtIndexPath
indexPath: NSIndexPath) -> UITableViewCell {
// Dequeue your cell and other code goes here.
// set the button's tag like below.
cell.innerCellButton.tag = indexPath.row
return cell
}
Close. I wouldn't use Suresh's method since it does not help find the IndexPath, which includes section and row.
First, I would recommend a model object for your table view data source. Learn more about the MVC pattern as well as parsing a JSON response to an object with mapping. However, this would give you the data you want.
func cellButtonTapped(cell: UITableViewCell) {
let indexPath = tableView.indexPathForCell(cell)
let resultList = self.items["result"] as! [[String: AnyObject]]
let itemForThisRow = resultList[indexPath.row]
let name = itemForThisRow["name"] as! String
}
In my App I use UITableView with custom cells.
for each cell I implement function to create it, and call these functions in cellForRow.
this is an code example from project :
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
if indexPath.row == CellsTypes.profileImageCell.rawValue {
return createIntroCell()
}
else if indexPath.row == CellsTypes.fullNameCell.rawValue {
return createUserNameCell()
}
else if indexPath.row == CellsTypes.emailCell.rawValue {
return createEmailCell()
}
else {
return createPasswordCell()
}}
and these are the creation functions :
func createUserNameCell() -> TextFieldTableViewCell {
let fullNameCell = self.tableView.dequeueReusableCellWithIdentifier("text-field-cell") as! TextFieldTableViewCell
fullNameCell.awamirTextFieldNib.setNormalTextFieldCellContent("Full Name")
fullNameCell.awamirTextFieldNib.textFieldContent.tag = CellsTypes.fullNameCell.rawValue
fullNameCell.awamirTextFieldNib.textFieldContent.returnKeyType = .Next
fullNameCell.awamirTextFieldNib.textFieldContent.delegate = self
return fullNameCell
}
func createEmailCell() -> TextFieldTableViewCell {
let emailCell = self.tableView.dequeueReusableCellWithIdentifier("text-field-cell") as! TextFieldTableViewCell
emailCell.awamirTextFieldNib.setNormalTextFieldCellContent("Email")
emailCell.awamirTextFieldNib.textFieldContent.tag = CellsTypes.emailCell.rawValue
emailCell.awamirTextFieldNib.textFieldContent.returnKeyType = .Next
emailCell.awamirTextFieldNib.textFieldContent.delegate = self
return emailCell
}
func createPasswordCell() -> TextFieldTableViewCell {
let textFieldCell = self.tableView.dequeueReusableCellWithIdentifier("text-field-cell") as! TextFieldTableViewCell
textFieldCell.awamirTextFieldNib.setPasswordCellContent("Password")
textFieldCell.awamirTextFieldNib.textFieldContent.tag = CellsTypes.passwordCell.rawValue
textFieldCell.awamirTextFieldNib.textFieldContent.returnKeyType = .Next
textFieldCell.awamirTextFieldNib.textFieldContent.delegate = self
return textFieldCell
}
the problem is if I reload the tableview the content of cells changed because of the reusablity of the cells. i.e: after reload the tableview the content of the first cell become in the second cell, and the content of the sencond on became in the first cell!!
how can I prevent tableview from reusable the cells?!
Thanks.
Try using a different identifier for each of the cell types, so dont use "text-field-cell" for each one, make one "full name", "password" etc. not sure how you are going about creating your cells, but if you are using the registerNib or registerClass, you will need to register it for each different identifier
self.tableView.registerNib(UINib(nibName: "CustomCell", bundle: nil), forCellReuseIdentifier: "full name")
self.tableView.registerNib(UINib(nibName: "CustomCell", bundle: nil), forCellReuseIdentifier: "password")
self.tableView.registerNib(UINib(nibName: "CustomCell", bundle: nil), forCellReuseIdentifier: "email")
Try to implement prepareForReuse method in your custom cell and set all fields text to nil.
override func prepareForReuse() -> Void {
awamirTextFieldNib.text = nil
}
Hope this help
Don't use the default UITableView and fight the reuse of cells, it's really embedded in it's behaviour.
Try to adapt your code so it works well with reusing cells, or if that's really impossible, you'd have to write your own custom table view I guess (but I don't recommend that at all)
You shouldn't prevent that, but if you really want to, I think that not setting cell identifier to your UITableViewCell should do the trick. When you'll call dequeueReusableCellWithIdentifier, it will find no cell and will create a new one. But again, it's not recommended as UITableView is made to be used with reuse ability.
Moreover, as #Fonix suggests, using a different cell identifier for each cell of your UITableView might solve your issue while keeping using cell reuse system.
Edit :
As you're talking about losing text content in your UITextField, maybe the single change to make is changing your #propery weak attribute to strong.
Hope this helps.
I have a UITableViewController in which I use more than one custom cell. I have used multiple custom cells in the past with no problem, and I am using the same strategy to implement them as I have in the past so this error baffles me. First, some code:
This is how I register the custom cells in viewDidLoad:
// Registering the custom cell
let nib1 = UINib(nibName: "OmniCell", bundle: nil)
tableView.registerNib(nib1, forCellReuseIdentifier: "omniCell")
let nib2 = UINib(nibName: "RankCell", bundle: nil)
tableView.registerNib(nib2, forCellReuseIdentifier: "rankCell")
This is how I create them in cellForRowAtIndexPath:
let cell1: OmniCell = self.tableView.dequeueReusableCellWithIdentifier("omniCell") as! OmniCell
let cell2: RankCell = self.tableView.dequeueReusableCellWithIdentifier("rankCell") as! RankCell
when I comment out the code related to the second custom cell the program runs fine, but when both custom cells are used I get this error:
this class is not key value coding-compliant for the key rankCell.
Both custom cells are implemented in an identical manner so I am not sure why the second custom cell generates this error while the first one does not. What am I missing?
Update: Upon request I am sharing the entire cellforrowatindexpath func:
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
// This line works:
let cell1: OmniCell = self.tableView.dequeueReusableCellWithIdentifier("omniCell") as! OmniCell
// It is this line that breaks if not commented out:
let cell2: RankCell = self.tableView.dequeueReusableCellWithIdentifier("rankCell") as! RankCell
// This line works:
let cell3: ProgressCell = self.tableView.dequeueReusableCellWithIdentifier("progressCell") as! ProgressCell
if indexPath.row == 0 {
return cell1
} else if indexPath.row == 1 {
return cell2
} else {
return cell3
}
}
I managed to resolve this. The problem was that there was an errant connection in the XIB. Refer to this picture:
There was an additional "broken" outlet above the one good one that was like:
rankCell ---> Rank Cell
But instead of a filled in circle it had what appeared to be an elongated symbol that was too small to make out. I removed the outlet and the app built and ran normally. I am not sure where that connection came from, none of the other custom cells had one like it.
I am developing news feed and I am using uitableview to display data. I am loading each cell data synchronically in other thread and use protocol method to display loaded data:
func nodeLoaded(node: NSMutableDictionary) {
for var i = 0; i < nodesArray.count; ++i {
if ((nodesArray[i]["id"] as! Int) == (node["id"] as! Int)) {
nodesArray[i] = node
}
}
}
The problem is that when I scroll my uitableview (while data synchronically loading), some of my cells repeats (8 row has same content like first, or 6 row has the same content like second row). When I scroll after some time (I suppose after data is loaded) then all become normal.
I looking for answers and found that I have to check if cell is nill at cellForRowAtIndexPath, but in swift my code is different then in objective C:
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell: NewsCell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! NewsCell
var node = nodesArray[indexPath.row] as! NSDictionary
if (node["needLoad"] as! Bool) {
dbHelper.getNode(node["id"] as! Int, hash: node["id"] as! Int, tableName: DbHelper.newsTableName, callback: self)
} else {
cell.id = node["id"] as! Int
cell.titleLabel.text = node["title"] as? String
cell.descriptionLabel.text = node["description"] as? String
cell.imgView.image = WorkWithImage.loadImageFromSD((node["image"] as! String))
}
return cell
}
Also I can't check if cell == nil bcs of binary error (NewsCell can't be nil).
What should I do? Thx.
you seem to have created a separate class for UITableViewCell. The problem with your code is that you are not resetting the labels when reuse happens.
Oveeride prepareForReuse method in your custom UITableviewCell class and reset your interfaces there. That should fix the issue.