Hello fellow programmers! I have a challenge I need help with. I have built a table using a Custom Style Cell.
This cell simply has a Label and UISwitch. The label displays a name and the switch displays whether they are an Admin or not. This works perfectly. My challenge is how and where do I put code to react when the switch is changed.
So if I click the switch to change it from off to on where can I get it to print the persons name? If I can get the name to print I can do the php/sql code myself. Thanks and here is a snippet from my code.
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell: UITableViewCell = tableView.dequeueReusableCellWithIdentifier(kCellIdentifier) as UITableViewCell
let admin = self.admin[indexPath.row]
let text1a = admin.FirstName
let text1aa = " "
let text1b = admin.LastName
let text1 = text1a + text1aa + text1b
(cell.contentView.viewWithTag(1) as UILabel).text = text1
if admin.admin == "yes" {
(cell.contentView.viewWithTag(2) as UISwitch).setOn(true, animated:true)
} else if admin.admin == "no" {
(cell.contentView.viewWithTag(2) as UISwitch).setOn(false, animated:true)
}
return cell
}
You have to set an action in your Custom Table View Cell to handle the change in your UISwitch and react to changes in it, see the following code :
class CustomTableViewCell: UITableViewCell {
#IBOutlet weak var label: UILabel!
#IBAction func statusChanged(sender: UISwitch) {
self.label.text = sender.on ? "On" : "Off"
}
}
The above example is just used to change the text of the UILabel regarding the state of the UISwitch, you have to change it in base your requirements of course. I hope this help you.
You need to listen .ValueChanged of UISwitch, in YOUR_CUSTOM_CELL to make some decisions. There you can catch to "println" your data.
Eric,
At some point in the tableview's lifecycle, you'll need to configure each UISwitch in the table cell with a target/action.
https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIControl_Class/index.html#//apple_ref/occ/instm/UIControl/addTarget:action:forControlEvents:
The action tells the UISwitch instance what method it should invoke when the switch is flipped by the user. The target tells the UISwitch instance what object is hosting that method.
Typically, you'll use the UITableViewController (or UIViewController) subclass as the target.
Related
That is my footerView called FooterTableViewCell. I have this protocol called SurveyAnswerTableViewCellDelegate. It's parent is AddQuestionViewController.
When I tap on the footerView I trigger #IBActtion.
#objc protocol SurveyAnswerTableViewCellDelegate: AnyObject {
func textSaved(_ text: String)
}
class FooterTableViewCell: UITableViewHeaderFooterView {
var parentVC: AddQuestionViewController!
#IBAction func addNewTapped(_ sender: Any) {
print("tapped")
let newTag = model.tag + 1
parentVC.addNewAnswer()
}
This button action triggers AddQuestionViewController
class AddQuestionViewController: SurveyAnswerViewDelegate, UITextFieldDelegate, UITableViewDelegate, SurveyAnswerTableViewCellDelegate {
var answers: [SurveyAnswerModel] = []
var savedText : String = ""
static var delegate: SurveyAnswerTableViewCellDelegate?
I try creating an empty string and append a new answer to my array. But this text here is always "".
func addNewAnswer() {
let newAnswer = SurveyAnswerModel(answer: savedText, tag: 0)
self.answers.append(newAnswer)
self.tableView.reloadData()
}
func textSaved(_ text: String) {
savedText = text
}
The textfield I try to read is inside SurveyAnswerTableViewCell while setting up the cell inside the tableview I call setup function.
class SurveyAnswerTableViewCell: UITableViewCell {
#IBOutlet weak var textField: UITextField!
weak var delegate: SurveyAnswerTableViewCellDelegate?
var parentVC: AddQuestionViewController!
func setup() {
if let text = self.textField.text {
self.delegate?.textSaved(textField.text!)
}
}
extension AddQuestionViewController: UITableViewDataSource {
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(forIndexPath: indexPath) as SurveyAnswerTableViewCell
cell.parentVC = self
cell.setup()
return cell
}
How can I successfully send that text to AddQuestionViewController so it appends a new answer with correct string
There are a few things keeping this from working.
You are calling SurveyAnswerTableViewCell's setup() function directly after dequeuing the cell for reuse. It has not yet (re)appeared on the screen at that point, so the user has not had a chance to enter anything into the text field.
You don't currently set the delegate property of SurveyAnswerTableViewCell to anything, so even if the textfield had valid input, the delegate would be nil and delegate?.textSaved(textField.text!) wouldn't do anything.
Both of the previous points mean that the value of AddQuestionViewController .savedText never gets updated from the empty string. So when addNewAnswer() tries to read it, it will always see that empty string.
Rather than reading the text field when the cell is dequeued, it would make more sense to save the text field value when the user is done typing.
To do that, conform the cell to UITextFieldDelegate and implement the textFieldDidEndEditing(_:) method. From within that method you can then call the delegate method you already have to save the text. Make sure the delegate property on the cell has been set by the VC, or else this won't do anything!
The VC itself should not have a delegate property of type SurveyAnswerTableViewCellDelegate. It serves as the delegate, rather than having one. If this doesn't quite make sense, I would recommend reviewing some online resources on the delegate pattern.
So make sure the ViewController conforms to SurveyAnswerTableViewCellDelegate and then set the cell's delegate value to the VC. The cellForRowAt function should then look something like this:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(forIndexPath: indexPath) as SurveyAnswerTableViewCell
cell.delegate = self
return cell
}
As a side note, neither the footer nor the cell should have a reference to the parent view controller. as a general rule it is good to avoid subviews being aware of their parent views. Things get unnecessarily complicated when there is two-way knowledge sharing between components, and it makes the subview much less reusable. I would recommend making a delegate for the footer as well, and removing the parentVC property from both the footer and the cell.
Here's what it looks like is happening:
Button tapped
addNewTapped(_:) invoked
addNewAnswer() invoked
newAnswer is appended to answers
tableView.reloadData() invoked
Cells are regenerated with new/empty textfields (so delegate.textSaved is never invoked)
so I'm not sure what you're trying to do, but here's what I figure are a couple possible routes:
store UITextFields separately and add them into table cells so they're not removed by a table reload
conform AddQuestionViewController to UITextFieldDelegate and set it as the textfields' delegate to observe textfield texts changing (and if you're only using 1 textfield, you could set savedText there)
I'm trying to read data from CoreData into a custom cell. This is just a test app before I try moving to the real app that I've been working on. The data is there - I can print it to the console and see it. For some reason, even with constraints, all of the data is laid on top of each other in the cell. Can anyone see what's going on with this?
I've created constraints to keep the cells where they should be, but when the data is loaded from my 'show data' button, the data is laid on top of each other.
Here is my custom cell class:
import UIKit
class CustomCellClass: UITableViewCell {
#IBOutlet weak var txtNameLabel: UILabel!
#IBOutlet weak var txtAgeLabel: UILabel!
}
Here is the ShowData class: (partial)
class ShowData: UIViewController, NSFetchedResultsControllerDelegate {
#IBOutlet weak var personTableView: UITableView!
let appDelegate = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
var personData = [Person]()
// Read the data
override func viewDidLoad() {
super.viewDidLoad()
personTableView.delegate = self
personTableView.dataSource = self
loadItems()
}
func loadItems() {
let request : NSFetchRequest<Person> = Person.fetchRequest()
do {
personData = try appDelegate.fetch(request)
} catch {
print("couldn't load")
}
}
}
extension ShowData : UITableViewDataSource, UITableViewDelegate {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return personData.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let person = personData[indexPath.row]
let cell = tableView.dequeueReusableCell(withIdentifier: "personNameAge", for: indexPath) as! CustomCellClass
cell.txtNameLabel?.text = person.name
cell.txtAgeLabel?.text = String(person.age)
return cell
}
Here is a screenshot of the tableview while running:
Edit:
I just deleted the app from the simulator and tried to rerun - now there isn't any data in the cells.
Just to clarify for other readers, as can be seen in your screenshot, the rows in your table are separated as expected but the different fields in each cell, what one might call the columns, are on top of one another.
You say that you have created constraints to keep the cells where they should be, I'm not sure what you mean by that. What you need is constraints for the fields within each cell – what I call intra-cell constraints. Either you have not added these constraints, or there is a mistake in them which causes all fields to be drawn at the left.
To show you what I mean, let's use the example of a little workout app of mine which has, in each table cell, from left to right, a Perform button, an Edit button, a Name field and a Duration field. The screenshot below shows, in the big yellow box, the intra-cell constraints. If you are using a storyboard, the problem with your app must be in that area. If you are not using a storyboard, the problem must be in the equivalent code (or lack of it).
Just to let everyone know. The issue is resolved. I removed the table view cell from the project, readded, and readded the constraints. Everything is working now. I'm not sure where the problem was, but I noticed I had weird wrapping happening. I moved one of the labels to the other side of the cell and constrained it to the right side, and the other to the left side. When I ran the app, the text appeared to word wrap. I decided to delete the cell and readd and relink my outlets. It worked the first time...
I have a UITextView inside each cell of a UITableView
I am using Core Data to save data which is typed in the UITextView
I would like to save the text typed in UITextView once the user is done editing it
I have added UITextViewDelegate to my TableViewCell class
I am using Notifications to post the new text to the TableViewController
I am able to get the new text to the TableViewController but I don't know how to get the row number of the cell that contained the textview wherein the text was typed. I need to know the row number (or the object in that row) to update the correct NSManagedObject.
What I have Tried:
I was thinking about using tags but since I need to constantly add and delete rows it wouldn't be the best approach
I have tried using DidSelectedRowAtIndexPath but it doesn't get triggered while the
user taps the UITextView (UITextView covers up to 80% of the one cell)
In the TableViewCell class, I have:
func textViewDidEndEditing(_ textView: UITextView) {
// Post notification
let userInfo = [ "text" : textView.text]
NotificationCenter.default.post(
name: UITextView.textDidEndEditingNotification,
object: nil,
userInfo: userInfo as [AnyHashable : Any])
}
In the TableViewController, I have:
//Subscribe
NotificationCenter.default.addObserver(self,
selector: #selector(textEditingEnded(notification:)),
name: UITextView.textDidEndEditingNotification,
object: nil)
#objc func textEditingEnded(notification:Notification) {
guard let text = notification.userInfo?["text"] as? String else {return}
print ("text: \(text)")
}
Don't hesitate to ask for more details.
I'll appreciate every bit of help I can get!
Create a property of the NSManagedObject type in the table view cell.
In Interface Builder connect the delegate of the text view to the cell.
In the controller pass the appropriate data source item in cellForRowAt to the cell.
Delete the observer and instead of posting a notification change the attribute in the NSManagedObject instance directly and save the context.
As NSManagedObject instances are reference types the changes will persist.
I hope you can have variable inside your UITableViewCell subclass for certain item
var item: Item?
then in cellForRowAt set certain item for certain cell
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = ...
...
cell.item = array[indexPath.row]
...
}
now you can implement UITextViewDelegate to your cell subclass and you can use method textViewDidEndEditing for handling when user is done with typing
class YourCell: UITableViewCell {
...
var item: Item?
...
override func awakeFromNib() {
yourTextView.delegate = self
}
}
extension YourCell: UITextViewDelegate {
func textViewDidEndEditing(_ textView: UITextView) {
... // here save text and here you can use variable `item`
}
}
I have a collectionView of buttons as pictured below. I want to be able to select multiple of these cells, and in doing so pass the title of each selected button into an array of Strings.
UICollectionView - each cell has a button with a title
The UICollectionView is in WordViewController class
class WordViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout
And the UICollectionViewCell is in it's own file.
import UIKit
class WordCollectionViewCell: UICollectionViewCell {
#IBOutlet weak var wordView: UIButton!
#IBAction func buttonTapped(_ sender: UIButton) {
if wordView.isSelected == true {
wordView.isSelected = false
wordView.backgroundColor = UIColor.blue
}else {
wordView.isSelected = true
wordView.backgroundColor = UIColor.green
}
}
}
I'm very new to Swift and I have been trying to find an answer to this for days, but I can't figure it out. I suspect I may have to use indexPathsForSelectedItems but I have tried this and can't get it working.
func indexSelected () {
let collectionView = self.collectionView
let indexPath = collectionView?.indexPathsForSelectedItems?.first
print(indexPath!)
let cell = collectionView?.cellForItem(at: indexPath!) as? WordCollectionViewCell
let data = cell?.wordView.currentTitle
print(data!)
}
I'm not sure if I have something fundamental wrong in the way I have set up my CollectionView or if it is something to do with me using buttons within the CollectionViewCells.
Any help would be very appreciated.
This is one way you could do it. First get the indexPaths for the selected cells. Then loop through the indexPaths and get your cell for each IndexPath (cast them as your custom CollectionViewCell to access your button). Now you can append each title to an array to save them.
var titleArray = [String]()
guard let selectedIndexPaths = collectionView.indexPathsForSelectedItems else { return }
for indexPath in selectedIndexPaths {
if let cell = collectionView.cellForItem(at: indexPath) as? WordCollectionViewCell {
self.titleArray.append(cell.yourButton.titleLabel?.text)
}
}
Welcome to SO. This sounds a bit like an X/Y problem: A case where you are asking about how to implement a specific (often sub-optimal) solution rather than asking about how to solve the problem in the first place.
You should not treat the views in your collection view as saving data. (buttons are views.)
You should use the button to figure out the indexPath of the cell the user tapped and then look up the information in your data model.
You should set up an array of structs (or an array of arrays, if your collection view is in sections of rows.) Each of those structs should contain the current settings for a cell.
Your collectionView(_:cellForItemAt:) method should use the array of structs to configure your sell for display.
As the user taps buttons and selects cells, you should update the struct(s) at the appropriate IndexPath(s) and then tell the collection view to update those cell.
If you need to do something with the selected cells, you should ask the collection view for an array of the selected cells, you should use those IndexPaths to index into your model array and fetch the struct for each IndexPath, and then look up teh data you need.
EDIT:
You can use a really simple extension to UICollectionView to find the indexPath of any view inside your collection view (and a button is a view, as mentioned...)
extension UICollectionView {
func indexPathForCellContaining( view: UIView) -> IndexPath? {
let viewCenter = self.convert(view.center, from: view.superview)
return self.indexPathForItem(at: viewCenter)
}
}
I have multiple buttons. Each button contains a language label.
I want to make it so that when users tap on the button, the selected language label changes its value according to the button tapped.
The selected language outlet is called SelectedLangText.
A simple solution would be to create multiple Action outlets for each button and set the value of SelectedLangText label. However, if there would be 100 buttons, that would be bad coding.
I'm not sure how to approach this situation in Swift 3 coming from web development.
I prefer using the delegate design pattern when it comes to solving an issue like that for it I find it to be a much cleaner approach than just a mass amount of #IBActions
1- Create a Language class
import Foundation
class Language {
var id: Int
var name: String
init(id: Int, name: String) {
self.id = id
self.name = name
}
}
2- Create the custom cell in the storyboard or nib and then add the appropriate outlets and actions. And then you create a Delegate protocol for it
import UIKit
protocol CustomCellDelegate: class {
func customCell(newLanguageSelected language: Language)
}
class CustomCell: UITableViewCell {
var language: Language!
#IBOutlet weak var languageTextLabel: UILabel!
weak var delegate: CustomCellDelegate?
func setupCustomCell(withLanguage language: Language){
self.language = language
self.languageTextLabel.text = self.language.name
}
#IBAction func buttonPressed(sender: UIButton){
delegate?.customCell(newLanguageSelected: self.language)
}
}
3- Finally add the implementation in the cellForRow method of the UITableViewDataSource and add the implementation of the delegate in the UITableViewController class
import UIKit
class YourTableViewController: UITableViewController{
var languages: [Language] = []
//implement the other methods in the dataSource
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "reuse", for: indexPath) as! CustomCell
cell.delegate = self
cell.setupCustomCell(withLanguage: languages[indexPath.row])
return cell
}
}
extension YourTableViewController: CustomCellDelegate{
func customCell(newLanguageSelected language: Language) {
//Do what you will with the language
}
}
Good luck
You can add Tags to each button and Set same IBAction for all buttons.
First in your method get the language based on the button.
Now use loop(go with for loop as you will need proper index for each button) and get all buttons from its tag and set language tag.
A bit complex at glance, but will solve your problem and good solution in my eye.
for index in 101...103 {
let myBtn = self.view.viewWithTag(index) as! UIButton
myBtn.setTitle("localisedtitle string", for: .normal)
}