Hi i'm trying to add UITableview inside a UITableViewCell. I had connected the outer tableview cell to the view controller and the inner tableview(inside the cell) to the custom cell class and do the following code
//cellforrow of the outer tableview:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell{
let cell = tableView.dequeueReusableCellWithIdentifier("HistoryCell")! as! OrderHistoryTableViewCell
print(ordersArray[indexPath.row].valueForKey("items"))
cell.lbl_orderStatus.text = ordersArray[indexPath.row].valueForKey("status") as? String
cell.lbl_time.text = ordersArray[indexPath.row].valueForKey("timestamp") as? String
let vc = OrderHistoryTableViewCell() // Custom cell class
vc.tableview_reload(ordersArray[indexPath.row]as! NSMutableDictionary) //pass value to the tableview inside the cell
return cell
}
//code in the custom cell class
func tableview_reload(dict : NSMutableDictionary){
orderItemsarray.removeAllObjects()
let itemsDict = dict.valueForKey("items") as! NSMutableDictionary
for (_,value) in itemsDict
{
let tempDict = value as! NSMutableDictionary
orderItemsarray.addObject(tempDict)
}
self.tbl_Items.reloadData() // fatal error: unexpectedly found nil while unwrapping an optional value
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
return self.orderItemsarray.count;
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell{
var cell : UITableViewCell!
cell = UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: "cell");
cell.textLabel?.text = "test"
return cell
}
The data is passed and the func tableview_reload in the custom cell class is called. But when i try to reload the tableview in the custom cell class fatal error:
unexpectedly found nil while unwrapping a optional value occurs.
I had checked the outlet connection and it is connected to the custom cell class. Please advice
Instead of creating new instance using OrderHistoryTableViewCell() you need to use reused cell that you have created using dequeueReusableCellWithIdentifier, so remove line let vc = OrderHistoryTableViewCell() and call tableview_reload method on cell.
cell.tableview_reload(ordersArray[indexPath.row]as! NSMutableDictionary)
return cell
Related
I am creating a UITableView that enables the user to add a variable amount of data. Table looks like this initially:
When the user clicks on the "+" button, i would like to add a new cell with a UITextField for entering data. This new cell is a Custom UITableViewCell called "RecordValueCell". Here's what is looks like:
//Custom UITableViewCell
class RecordValueCell : UITableViewCell {
#IBOutlet weak var textField: UITextField!
#IBOutlet weak var deleteButton: UIButton!
var onButtonTapped : ((_ sender : UIButton)->Void)?
#IBAction func deleteButtonTouched(_ sender: Any) {
guard let senderButton = sender as? UIButton else {
return
}
onButtonTapped?(senderButton)
}
}
However when i try to add another cell, using the tableView.dequeueReusableCell(withIdentifier: ) function, it seems to return the same cell. And here is what my UI looks like:
Empty space at the top of the section where my new cell should be. Here is the code to add the cell:
func addNewValueCell() {
guard let reusableValueCell = self.tableView.dequeueReusableCell(withIdentifier: "valueCell") as? RecordValueCell else {
fatalError("failed to get reusable cell valueCell")
}
var cell = Cell() //some custom cell Object
//add the gray horizontal line you see in the pictures
reusableValueCell.textField.addBorder(toSide: .Bottom, withColor: UIColor.gray.cgColor, andThickness: 0.5)
reusableValueCell.onButtonTapped = { (sender) in
self.removeValue(sender: sender)
}
cell.cell = reusableValueCell
self.sections[self.sections.count - 1].cells.insert(cell, at: 0)
//When i put a break point at this spot, i find that reusableValueCell is the same object as the cell that is already being used.
tableView.reloadData()
reusableValueCell.prepareForReuse()
}
When i debug it, i find that dequeueReusableCell(withIdentifier: ) returns the exact same RecordValueCell multiple times.
Here is my cellForRowAt:
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
guard let cell = self.sections[indexPath.section].cells[indexPath.row].cell else {
fatalError("error getting cell")
}
return cell
}
numberOfRowsInSection
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.sections[section].cells.count
}
First of all, you will need to set the View Controller Class that this table is contained in as the table's UITableViewDataSource
tableView.dataSource = self // view controller that contains the tableView
Create an array of strings as member of your View Controller class which contains the data for each cell:
var strings = [String]()
Then you will need to implement the following method for the UITableViewDataSource protocol:
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return strings.count
}
You should also be dequeueing the cells in your cellForRowAt method like so:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: yourIdentifier) as! YourCellClass
cell.textLabel = strings[indexPath.row]
return cell
}
Then whenever the user enters into the textField, their input will be appended to this array:
let input = textField.text
strings.append(input)
tableView.reloadData()
Once the data is reloaded, the cell will be added to the table automatically since the number of rows are defined by the String array's length and the label is set in the cellForRowAt method.
This feature is very easy to implement if you will do in a good way.
First, you have to create two TableCell. First to give the option to add a record with plus button and second for entering a value with textfield. Now always return first cell (AddRecordTableCell) in the last row in tableView, and return the number of rows according to entered values like
return totalValues.count + 1
I am getting following errors:
1) Non-optional expression of type 'UITableViewCell' used in a check for optionals
2) Value of type 'UITableViewCell' has no member 'congigureCell'
Please
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if let cell:UITableViewCell = countryList.dequeueReusableCell(withIdentifier: "cell")! as UITableViewCell // Error 1 happens here {
let text: String!
if inSearchMode {
text = filteredCountriesList[indexPath.row]
} else {
text = countriesList[indexPath.row]
}
cell.congigureCell(text: text) // Error 2 happens here
return cell
} else {
return UITableViewCell()
}
}
1) The ! mark at the end of
countryList.dequeueReusableCell(withIdentifier: "cell")!
uses force unwrap to make it non-optional, so you shouldn't check it inside if let, or even better way is to just remove ! mark
2) congigureCell probably the method of different class, not UITableViewCell. You should substitude UITableViewCell by this class to cast it
Make sure you have done following steps.
Add cell identifier in storyboard to your custom cell. i.e "cell"
Assign delegate and datasource of your YourTableview to YOURViewController.swift via storyboard or in code.
In YOURViewController.swift access cell using datasource of table
view as.
Add a custom class of sub class UITableViewCell and assign it to
tour cell in storyboard.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if let cell = countryList.dequeueReusableCell(withIdentifier: "cell") as! YOURTableViewCellClass {
let text: String!
if inSearchMode {
text = filteredCountriesList[indexPath.row]
} else {
text = countriesList[indexPath.row]
}
cell.congigureCell(text: text) // Error 2 happens here
return cell }
The ! mark is uses to force unwrap the optional value that can be nil. But "if let" and "guard let" has been check for optionals, so you don't need ! mark.
Just use
if let cell:UITableViewCell = countryList.dequeueReusableCell(withIdentifier: "cell") as UITableViewCell
cell in this line is 'UITableViewCell', but congigureCell is not a member of UITableViewCell.
If you want to use your own cell(like MyCell), you should convert it to MyCell.
let myCell = cell as! MyCell
1 .Instead of dequeueReusableCellWithIdentifier: use dequeueReusableCellWithIdentifier:forIndexPath: the later one never provides a nil value so you dont need to worry about the 'nil error'.
2.UItableViewCell dont have configure cell or congigureCell as in your case instead you have to create a custom tableViewCell and add function as configureCell() and then in this line
if let cell:UITableViewCell = countryList.dequeueReusableCell(withIdentifier: "cell")! as UITableViewCell
replace as UITableViewCell as as yourCustomTableViewCellClass
I have a UITableView in my ViewController.
One of the cell could be tap into another TableViewController to allow select a value.
I want to update my cell after back from the callee ViewController.
right now, i could pass back the selected value by delegate.
However, i tried following way, none of them works.
self.mainTable.reloadData()
dispatch_async(dispatch_get_main_queue()) {
self.mainTable.reloadData()
}
self.mainTable.beginUpdates()
self.mainTable.reloadRowsAtIndexPaths([indexPath], withRowAnimation: UITableViewRowAnimation.None)
self.mainTable.endUpdates()
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
was called and executed without error.
but the UI just doesn't change
here is the way I update value in cellForRowAtIndexPath
if let currentCell = tableView.cellForRowAtIndexPath(indexPath) as UITableViewCell! {
currentCell.textLabel?.text = address
return currentCell
}
Here is my cellForRowAtIndexPath -
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let id = "Cell"
println(indexPath)
if indexPath.row == 1 {
var cell = tableView.dequeueReusableCellWithIdentifier(id) as? UITableViewCell
if cell == nil {
cell = UITableViewCell(style: UITableViewCellStyle.Default, reuseIdentifier: id)
cell?.contentMode = UIViewContentMode.Center
cell?.selectionStyle = UITableViewCellSelectionStyle.None
cell?.contentView.addSubview(mapView!)
}
return cell!
}else{
let cell = UITableViewCell()
cell.textLabel?.text = self.address
return cell
}
}
Here is the delegate method -
func passBackSelectedAddress(address: String) {
self.address = address
var indexPath = NSIndexPath(forRow: 0, inSection: 0)
self.mainTable.beginUpdates()
self.mainTable.reloadRowsAtIndexPaths([indexPath], withRowAnimation: UITableViewRowAnimation.Automatic)
self.mainTable.endUpdates()
}
My fix:
After more debug, i find the cause,
the self.address value is updated in delegate, however it roll back to previous value in cellForRowAtIndexPath.
I change the property to a static property, then resolve the problem.
I'm not sure what's wrong with instance property, and why it reverses back.
static var _address:String = ""
It seems like you're trying to grab a cell from the UITableView and then update the textLabel value that way. However, UITableView and UITableViewCell are not meant to be updated in this way. Instead, store the value of address in your class and update this value when the delegate calls back into your class. If cellForRowAtIndexPath constructs the UITableViewCell with the value of self.address, calling mainTable.reloadData() after should update the cell to the new value.
For example:
var address: String
func delegateCompleted(address: String) {
self.address = address
self.mainTable.reloadData()
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier(<your identifier>)
if (indexPath == <your address cell indexPath>) {
let textLabel = <get your textLabel from the cell>
textLabel?.text = self.address
}
return cell
}
Your cellForRowAtIndexPath has some problems -
You are using the same re-use identifier for different types of cell (one with a map, one without)
When you allocate the table view cell for the other row, you don't include the re-use identifier.
You have no way of referring to the map view that you are adding after the method exits because you don't keep a reference.
If you are using a storyboard then you should create the appropriate prototype cells and subclass(es) and assign the relevant cell reuse ids. If you aren't then I suggest you create a cell subclass and register the classes against the reuse identifiers. Your cellForRowAtIndexPath will then look something like -
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var returnCell:UITableViewCell
if indexPath.row == 1 {
var myMapCell = tableView.dequeueReusableCellWithIdentifier("mapCell", forIndexPath:indexPath) as MYMapCell
myMapCell.contentMode = UIViewContentMode.Center
myMapCell.selectionStyle = UITableViewCellSelectionStyle.None
// Set the properties for a map view in the cell rather than assigning adding an existing map view
returnCell=myMapCell
}else{
returnCell = tableView.dequeueReusableCellWithIdentifier("addressCell", forIndexPath:indexPath)
returnCell.textLabel?.text = self.address
}
return returnCell;
}
I have an iPhone app with iOS 8 and Swift.
I would like to set the checkmark accessory in a static table view with 3 rows. I use NSUserdefaults where I save a string. For the checkmark I use this code:
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var identifier = defaults.objectForKey("Sort") as! String
let cell = tableView.dequeueReusableCellWithIdentifier("\(identifier)") as! UITableViewCell
cell.accessoryType = UITableViewCellAccessoryType.Checkmark
return cell
}
But it doesn't work. I always get the error:
fatal error: unexpectedly found nil while unwrapping an Optional value
on this line:
let cell = tableView.dequeueReusableCellWithIdentifier(identifier) as! UITableViewCell
I did not forget to set the cell identifier in the storyboard.
Since you are using static cells, in which case you only have 3, you could set up IBOutlet in storyboard.
#IBOutlet weak var cell1: UITableViewCell!
#IBOutlet weak var cell2: UITableViewCell!
#IBOutlet weak var cell3: UITableViewCell!
Subsequently, while you are still in storyboard, please set up tags for each cell, by clicking on the Attributes Inspector on the right.
For test, I set up the tags from 0 - 2 (i.e., 0, 1, 2).
I am guessing that you are saving a String value in you main controller, and once clicked, you would like so that the corresponding cell would have a checkmark by getting that value out of NSDefault again.
You could do this in method (Swift-wise: function):
override func tableView(tableView: UITableView, willDisplayCell cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath)
Here is what I came up as a quick test:
override func tableView(tableView: UITableView, willDisplayCell cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath)
{
NSUserDefaults.standardUserDefaults().setObject("0", forKey: "Sort")
NSUserDefaults.standardUserDefaults().synchronize()
let defaults: NSUserDefaults = NSUserDefaults.standardUserDefaults()
var aString = defaults.valueForKey("Sort") as? String
let cellIndex = aString?.toInt()
if cell1.tag == cellIndex
{
cell1.textLabel!.text = "Hallo, I am cell 1"
cell1.accessoryType = UITableViewCellAccessoryType.Checkmark
}
else if cell2.tag == cellIndex
{
cell2.textLabel!.text = "Hello, I am cell 2"
cell2.accessoryType = UITableViewCellAccessoryType.Checkmark
}
else if cell3.tag == cellIndex
{
cell3.textLabel!.text = "Hello, I am cell 3"
cell3.accessoryType = UITableViewCellAccessoryType.Checkmark
}
}
As test, I set it as 0 and get it back immediately from NSDefault; and the first cell is checked with a checkmark.
If you use static table view cells, tableView.dequeueReusableCellWithIdentifier will always return nil. This causes the error.
As an alternative, you can set the checkmars in the viewWillAppear function. There, you can access the cells via the tableView.cellForRowAtIndexPath function:
override func viewWillAppear(_ animated: bool) {
super.viewWillAppear(animated)
let cell = tableView.cellForRowAtIndexPath(NSIndexPath(forRow: 0, inSection: 0)) as UITableViewCell
cell.accessoryType = UITableViewCellAccessoryType.Checkmark
...
}
(replace the values of the forRow and inSection parameters as you need)
I have a tableview in my app and when I start my app it crashes on the following function.
func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
// Configure the cell...
let cellId: NSString = "Cell"
var cell: UITableViewCell = tableView.dequeueReusableCellWithIdentifier(cellId) as UITableViewCell
}
It crashes on the line of var cell
It gives the following error:
I can't figure out what's wrong with my code.
The whole function:
func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
// Configure the cell...
let cellId: NSString = "Cell"
var cell: UITableViewCell = tableView.dequeueReusableCellWithIdentifier(cellId) as UITableViewCell
let data: NSManagedObject = mylist[ip.row] as NSManagedObject
cell.textLabel.text = data.valueForKeyPath("voornaam") as String
cell.detailTextLabel.text = data.valueForKeyPath("achternaam") as String
return cell
}
EDIT:
What I got now:(Still gives the same error)
func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell? {
// Configure the cell...
let cellId: NSString = "Cell"
var cell: UITableViewCell? = tableView?.dequeueReusableCellWithIdentifier(cellId) as? UITableViewCell
if cell == nil {
cell = UITableViewCell(style: .Subtitle, reuseIdentifier: cellId)
}
let data: NSManagedObject = mylist[indexPath.row] as NSManagedObject
cell!.textLabel.text = data.valueForKey("voornaam") as String
cell!.detailTextLabel.text = data.valueForKey("achternaam") as String
//cell!.textLabel.text = "Hoi"
return cell
}
This is happening because the as operator is defined to cast an object to a given type and crash if the conversion fails. In this case, the call to dequeue returns nil the first time you call it. You need to use the as? operator, which will attempt to cast the given object to a type, and return an optional that has a value only if the conversion succeeded:
var cell: UITableViewCell? = tableView.dequeueReusableCellWithIdentifier(cellId) as? UITableViewCell
if cell == nil {
cell = UITableViewCell(style: .Subtitle, reuseIdentifier: cellId)
}
...
Because cell is now an optional value, use cell! when you want to call methods on it to force-unwrap the UITableViewCell inside it.
Additionally, your code had a second problem: it never created a fresh cell. dequeue will return nil the first time it's called on your table view. You need to instantiate a new UITableViewCell as in my code sample and then return it from the cellFor... method. The table view will then save the cell and return it on future calls to dequeue.
First off, why are you doing an optional binding on line if let ip = indexPath? This argument is not optional and you don't need to do optional binding or unwrap it. But this shouldn't cause your code to crash.
Remove your let data line and assign literal strings to your cells and see if it still crashes.
May I suggest that you check to see if you set the tableview's delegates? I made that mistake once in the flurry of setting everything else up.
Perhaps it is too late but I like to share my experience. I had similar error as I copied the entire code from another project. So I think the variables and functions won't be recognised so I had to drag them (cntr+drag) then it is solved.
Sorry if I couldn't explain better. I am new this.