i need an help, see this class
import UIKit
protocol TypesTableViewControllerDelegate: class {
func typesController(controller: TypesTableViewController, didSelectTypes types: [String])
}
class TypesTableViewController: UITableViewController {
let possibleTypesDictionary = ["bakery":"Bakery", "bar":"Bar", "cafe":"Cafe", "grocery_or_supermarket":"Supermarket", "restaurant":"Restaurant"]
var selectedTypes: [String]!
weak var delegate: TypesTableViewControllerDelegate!
var sortedKeys: [String] {
return possibleTypesDictionary.keys.sort()
}
// MARK: - Actions
#IBAction func donePressed(sender: AnyObject) {
delegate?.typesController(self, didSelectTypes: selectedTypes)
}
// MARK: - Table view data source
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return possibleTypesDictionary.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("TypeCell", forIndexPath: indexPath)
let key = sortedKeys[indexPath.row]
let type = possibleTypesDictionary[key]!
cell.textLabel?.text = type
cell.imageView?.image = UIImage(named: key)
cell.accessoryType = (selectedTypes!).contains(key) ? .Checkmark : .None
return cell
}
// MARK: - Table view delegate
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
tableView.deselectRowAtIndexPath(indexPath, animated: true)
let key = sortedKeys[indexPath.row]
if (selectedTypes!).contains(key) {
selectedTypes = selectedTypes.filter({$0 != key})
} else {
selectedTypes.append(key)
}
tableView.reloadData()
}
}
here the user can tap a cell of the tableView so that his prefer types are used on the next viewController for a search, now i need to build a class that do the same thing but there is no a tableview rather only 6 buttons in a view that the user can tap (so a viewController with only 6 different buttons to tap). The problem is that i don't know how to pass to the next viewController what buttons have been pressed and what are not, how can i build this class?
here is the function in the other class that need to know what buttons have been pressed
func fetchNearbyPlaces(coordinate: CLLocationCoordinate2D) {
mapView.clear()
dataProvider.fetchPlacesNearCoordinate(coordinate, radius:searchRadius, types: searchedTypes) { places in
for place: GooglePlace in places {
let marker = PlaceMarker(place: place)
marker.map = self.mapView
where is "types: serchedTypes"
What you wanna do is called delegation here is how you do it:
Make a protocol like this one:
protocol TransferProtocol : class
{
func transferData(types:[String])
}
Make the view controller with the buttons conform to that protocol, I like to do it by adding extensions to my classes like so:
extension ButtonsViewController:TransferProtocol{
func transferData(types:[String]){
//Do whatever you want here
}
}
Declare a variable in your Table View Controller class with the protocol you created as its type, this is called a delegate
weak var transferDelegate:TransferProtocol?
Before you segue to the Buttons View Controller you want to set that view controller as the delegate you just created like so:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let vc = segue.destination as? ButtonsViewController
transferDelegate = vc
vc?.transferData(types: selected)
}
If done correctly you should be able to work with the array you built in the Table View Controller(TypesTableViewController)
I'm a newbie to Swift and XCode, taking a class in iOS development this summer. A lot of projects we're doing and examples I'm seeing for UI elements like PickerViews, TableViews, etc. are defining everything in the ViewController.swift file that acts as the controller for the main view. This works fine, but I'm starting to get to the point of project complexity where I'd really like all of my code to not be crammed into the same Swift file. I've talked to a friend who does iOS development on the side, he said this is sane and reasonable and well in-line with proper object-oriented programming... but I just can't seem to get it to work. Through trial and error I've gotten to this situation: the app runs in the simulator, the UITableView appears, but I'm not getting it populated with entries. I can get it working just fine when all the code is in the ViewController, but once I start trying to create a new controller class and make an instance of that class the dataSource/delegate of the UITableView I start getting nothing. I feel like I'm either missing some core understanding of Swift here, or doing something wrong with the Interface Builder in XCode.
My end result should be a UITableView with three entries in it; currently I'm getting a UITableView with no entries. I'm following along with a few different examples I've Googled, but primarily this other SO question: UITableView example for Swift
ViewController.swift:
import UIKit
class ViewController: UIViewController{
#IBOutlet var stateTableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
var viewController = StateViewController()
self.stateTableView.delegate = viewController
self.stateTableView.dataSource = viewController
}
}
StateViewController.swift:
import UIKit
class StateViewController: UITableViewController{
var states = ["Indiana", "Illinois", "Nebraska"]
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
return states.count;
}
func tableView(cellForRowAttableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{
let cell = UITableViewCell(style:UITableViewCellStyle.default, reuseIdentifier:"cell")
cell.textLabel?.text = states[indexPath.row]
return cell
}
}
In XCode I have the UITableView hooked up to the View Controller; the outlets are set to dataSource and delegate and the referencing outlet is stateTableView.
I'm not getting any errors; I do get a warning on my `var viewController = StateViewController()' statement in ViewController.swift where it wants me to use a constant, but switching it to a constant doesn't change the behavior (this is as it should be, I assume).
Originally I assumed that the error was in my StateViewController.swift file, where I'm not creating an object that adheres to the UITableViewDataSource or UITableViewDelegate protocol, but if I even add them into the class statement I immediately get errors like "Redundant conformance of 'StateViewController' to protocol 'UITableViewDataSource'" - I'm reading that this is because inheriting from UITableViewController automatically inherits the other protocols as well.
The last thing I tried was instead referring to self.states in the StateViewController's tableView functions, but I'm pretty sure self in Swift works the same as it does in Python and it feels like I'm just trying to add magic words at this point.
I've investigated as far as my currently-limited Swift knowledge can take me, so any answer that explains what I'm doing wrong rather than just telling me what to fix would be very appreciated.
Your issue is being caused by a memory management problem. You have the following code:
override func viewDidLoad() {
super.viewDidLoad()
var viewController = StateViewController()
self.stateTableView.delegate = viewController
self.stateTableView.dataSource = viewController
}
Think about the lifetime of the viewController variable. It ends when the end of viewDidLoad is reached. And since a table view's dataSource and delegate properties are weak, there is no strong reference to keep your StateViewController alive once viewDidLoad ends. The result, due to the weak references, is that the dataSource and delegate properties of the table view revert back to nil after the end of viewDidLoad is reached.
The solution is to create a strong reference to your StateViewController. Do this by adding a property to your view controller class:
class ViewController: UIViewController{
#IBOutlet var stateTableView: UITableView!
let viewController = StateViewController()
override func viewDidLoad() {
super.viewDidLoad()
self.stateTableView.delegate = viewController
self.stateTableView.dataSource = viewController
}
}
Now your code will work.
Once you get that working, review the answer by Ahmed F. There is absolutely no reason why your StateViewController class should be a view controller. It's not a view controller in any sense. It's simply a class that implements the table view data source and delegate methods.
Although I find it more readable and understandable to implement dataSource/delegate methods in the same viewcontroller, what are you trying to achive is also valid. However, StateViewController class does not have to be a subclass of UITableViewController (I think that is the part that you are misunderstanding it), for instance (adapted from another answer for me):
import UIKit
// ViewController File
class ViewController: UIViewController {
var handler: Handler!
#IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
handler = Handler()
tableView.dataSource = handler
}
}
Handler Class:
import UIKit
class Handler:NSObject, UITableViewDataSource {
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 10
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("myCell")
cell?.textLabel?.text = "row #\(indexPath.row + 1)"
return cell!
}
}
You can also use adapter to resolve this with super clean code and easy to understand, Like
protocol MyTableViewAdapterDelegate: class {
func myTableAdapter(_ adapter:MyTableViewAdapter, didSelect item: Any)
}
class MyTableViewAdapter: NSObject {
private let tableView:UITableView
private weak var delegate:MyTableViewAdapterDelegate!
var items:[Any] = []
init(_ tableView:UITableView, _ delegate:MyTableViewAdapterDelegate) {
self.tableView = tableView
self.delegate = delegate
super.init()
tableView.dataSource = self
tableView.delegate = self
tableView.rowHeight = UITableViewAutomaticDimension
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
}
func setData(data:[Any]) {
self.items = data
reloadData()
}
func reloadData() {
tableView.reloadData()
}
}
extension MyTableViewAdapter: UITableViewDataSource, UITableViewDelegate {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return items.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.text = "Hi im \(indexPath.row)"
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
delegate?.myTableAdapter(self, didSelect: items[indexPath.row])
}
}
Use Plug and Play
class ViewController: UIViewController, MyTableViewAdapterDelegate {
#IBOutlet var stateTableView: UITableView!
var myTableViewAdapter:MyTableViewAdapter!
override func viewDidLoad() {
super.viewDidLoad()
myTableViewAdapter = MyTableViewAdapter(stateTableView, self)
}
func myTableAdapter(_ adapter: MyTableViewAdapter, didSelect item: Any) {
print(item)
}
}
You are trying to set datasource and delegate of UITableView as UITableViewController. As #Ahmad mentioned its more understandable in same class i.e. ViewController, you can take clear approach separating datasource and delegate of UITableView from UIViewController. You can make subclass of NSObject preferably and use it as datasource and delgate class of your UITableView.
You can also also use a container view and embed a UITableViewController. All your table view code will move to your UITableViewController subclass.Hence seprating your table view logic from your View Controller
Hope it helps. Happy Coding!!
The way I separate those concerns in my projects, is by creating a class to keep track of the state of the app and do the required operations on data. This class is responsible for getting the actual data (either creating it hard-coded or getting it from the persistent store). This is a real example:
import Foundation
class CountriesStateController {
private var countries: [Country] = [
Country(name: "United States", visited: true),
Country(name: "United Kingdom", visited: false),
Country(name: "France", visited: false),
Country(name: "Italy", visited: false),
Country(name: "Spain", visited: false),
Country(name: "Russia", visited: false),
Country(name: "Moldova", visited: false),
Country(name: "Romania", visited: false)
]
func toggleVisitedCountry(at index: Int) {
guard index > -1, index < countries.count else {
fatalError("countryNameAt(index:) - Error: index out of bounds")
}
let country = countries[index]
country.visited = !country.visited
}
func numberOfCountries() -> Int {
return countries.count
}
func countryAt(index: Int) -> Country {
guard index > -1, index < countries.count else {
fatalError("countryNameAt(index:) - Error: index out of bounds")
}
return countries[index]
}
}
Then, I create separate classes that implement the UITableViewDataSource and UITableViewDelegate protocols:
import UIKit
class CountriesTableViewDataSource: NSObject {
let countriesStateController: CountriesStateController
let tableView: UITableView
init(stateController: CountriesStateController, tableView: UITableView) {
countriesStateController = stateController
self.tableView = tableView
self.tableView.register(UITableViewCell.self, forCellReuseIdentifier: "UITableViewCell")
super.init()
self.tableView.dataSource = self
}
}
extension CountriesTableViewDataSource: UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// return the number of items in the section(s)
return countriesStateController.numberOfCountries()
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
// return a cell of type UITableViewCell or another subclass
let cell = tableView.dequeueReusableCell(withIdentifier: "UITableViewCell", for: indexPath)
let country = countriesStateController.countryAt(index: indexPath.row)
let countryName = country.name
let visited = country.visited
cell.textLabel?.text = countryName
cell.accessoryType = visited ? .checkmark : .none
return cell
}
}
import UIKit
protocol CountryCellInteractionDelegate: NSObjectProtocol {
func didSelectCountry(at index: Int)
}
class CountriesTableViewDelegate: NSObject {
weak var interactionDelegate: CountryCellInteractionDelegate?
let countriesStateController: CountriesStateController
let tableView: UITableView
init(stateController: CountriesStateController, tableView: UITableView) {
countriesStateController = stateController
self.tableView = tableView
super.init()
self.tableView.delegate = self
}
}
extension CountriesTableViewDelegate: UITableViewDelegate {
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
print("Selected row at index: \(indexPath.row)")
tableView.deselectRow(at: indexPath, animated: false)
countriesStateController.toggleVisitedCountry(at: indexPath.row)
tableView.reloadRows(at: [indexPath], with: .none)
interactionDelegate?.didSelectCountry(at: indexPath.row)
}
}
And this is how easy is to use them from the ViewController class now:
import UIKit
class ViewController: UIViewController, CountryCellInteractionDelegate {
public var countriesStateController: CountriesStateController!
private var countriesTableViewDataSource: CountriesTableViewDataSource!
private var countriesTableViewDelegate: CountriesTableViewDelegate!
private lazy var countriesTableView: UITableView = createCountriesTableView()
func createCountriesTableView() -> UITableView {
let tableViewOrigin = CGPoint(x: 0, y: 0)
let tableViewSize = view.bounds.size
let tableViewFrame = CGRect(origin: tableViewOrigin, size: tableViewSize)
let tableView = UITableView(frame: tableViewFrame, style: .plain)
return tableView
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
guard countriesStateController != nil else {
fatalError("viewDidLoad() - Error: countriesStateController was not injected")
}
view.addSubview(countriesTableView)
configureCountriesTableViewDelegates()
}
func configureCountriesTableViewDelegates() {
countriesTableViewDataSource = CountriesTableViewDataSource(stateController: countriesStateController, tableView: countriesTableView)
countriesTableViewDelegate = CountriesTableViewDelegate(stateController: countriesStateController, tableView: countriesTableView)
countriesTableViewDelegate.interactionDelegate = self
}
func didSelectCountry(at index: Int) {
let country = countriesStateController.countryAt(index: index)
print("Selected country: \(country.name)")
}
}
Note that ViewController didn't create the countriesStateController object, so it must be injected. We can do that from the Flow Controller, from the Coordinator or Presenter, etc. I did it from AppDelegate like so:
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
let countriesStateController = CountriesStateController()
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
if let viewController = window?.rootViewController as? ViewController {
viewController.countriesStateController = countriesStateController
}
return true
}
/* ... */
}
If it's never injected - we get a runt-time crash, so we know we must fix it straight away.
This is the Country class:
import Foundation
class Country {
var name: String
var visited: Bool
init(name: String, visited: Bool) {
self.name = name
self.visited = visited
}
}
Note how clean and slim the ViewController class is. It's less than 50 lines, and if create the table view from Interface Builder - it becomes 8-9 lines smaller.
ViewController above does what it's supposed to do, and that's to be a mediator between View and Model objects. It doesn't really care if the table displays one type or many types of cells, so the code to register the cell(s) belongs to CountriesTableViewDataSource class, which is responsible to create each cell as needed.
Some people combine CountriesTableViewDataSource and CountriesTableViewDelegate in one class, but I think it breaks the Single Responsibility Principle. Those two classes both need access to the same DataProvider / State Controller object, and ViewController needs access to that as well.
Note that View Controller had now way to know when didSelectRowAt was called, so we needed to create an additional protocol inside UITableViewDelegate:
protocol CountryCellInteractionDelegate: NSObjectProtocol {
func didSelectCountry(at index: Int)
}
And we also need a delegate property to make the communication possible:
weak var interactionDelegate: CountryCellInteractionDelegate?
Note that neither CountriesTableViewDataSource not CountriesTableViewDelegate class knows about the existence of the ViewController class. Using Protocol-Oriented-Programming - we could even remove the tight-coupling between those two classes and the CountriesStateController class.
I already posted a question but it was not clear about what I want. As #AlainT suggested, I filed a new one.
I have a typealias tuple
public typealias MyTuple<T> = (key: T, value: String)
A protocol:
public protocol VCADelegate: class {
associatedtype T
func didSelectData(_ selectedData: MyTuple<T>)
}
A view controller (VCA) with a table view
class VCA<T>: UIViewController, UITableViewDelegate, UITableViewDataSource {
var dataList = [MyTuple<T>]()
weak var delegate: VCADelegate? // Error: can only be used as a generic constraint
// ...
public func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
delegate?.didSelectData(dataList[indexPath.row])
}
}
In another view controller (VCB), I create a VCA and pass through a dataList
func callVCA() {
let vcA = VCA<String>()
vcA.dataList = [(key: "1", value:"Value 1"),
(key: "2", value:"Value 2")]
}
What I want to do is to have a dataList without knowing key's data type in VCA. Only when VCB calls VCA then I know the data type of the key. Creating a generic view controller will cause an issue with delegate. Any way to solve this problem without having to change to closure completion?
The other issue of using a generic view controller is I can't extend it. Any idea?
This is a standard type-erasure situation, though in this particular case I'd just pass a closure (since there's only one method).
Create a type eraser instead of a protocol:
public struct AnyVCADelegate<T> {
let _didSelectData: (MyTuple<T>) -> Void
func didSelectData(_ selectedData: MyTuple<T>) { _didSelectData(selectedData)}
init<Delegate: VCADelegate>(delegate: Delegate) where Delegate.T == T {
_didSelectData = delegate.didSelectData
}
}
Use that instead of a delegate:
class VCA<T>: UIViewController, UITableViewDataSource UITableViewDelegate {
var dataList = [MyTuple<T>]()
var delegate: AnyVCADelegate<T>?
// ...
public func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
delegate?.didSelectData(dataList[indexPath.row])
}
}
Your underlying problem is that protocols with associated types are not proper types themselves. They're only type constraints. If you want to keep it a PAT, that's fine, but then you have to make VCA generic over the Delegate:
class VCA<Delegate: VCADelegate>: UIViewController, UITableViewDelegate {
var dataList = [MyTuple<Delegate.T>]()
weak var delegate: Delegate?
init(delegate: Delegate?) {
self.delegate = delegate
super.init(nibName: nil, bundle: nil)
}
required init(coder: NSCoder) { super.init(nibName: nil, bundle: nil) }
public func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
delegate?.didSelectData(dataList[indexPath.row])
}
}
class VCB: UIViewController, VCADelegate {
func didSelectData(_ selectedData: MyTuple<String>) {}
func callVCA() {
let vcA = VCA(delegate: self)
vcA.dataList = [(key: "1", value:"Cinnamon"),
(key: "2", value:"Cloves")]
}
}
As a rule, protocols with associated types (PATs) are a very powerful, but special-purpose tool. They aren't a replacement for generics (which are a general purpose tool).
For this particular problem, though, I'd probably just pass a closure. All a type eraser is (usually) is a struct filled with closures. (Some day the compiler will probably just write them for us, and much of this issue will go away and PATs will be useful in day-to-day code, but for now it doesn't.)
I am using a custom cell class with a button in it.
import UIKit
protocol TouchDelegateForShotsCell {
func touchedTwitterButton()
}
class ShotsCell : UITableViewCell {
let touchDelegateForShotsCell: TouchDelegateForShotsCell = MasterViewController()
#IBAction func twitterButtonPressed(sender: AnyObject) {
touchDelegateForShotsCell.touchedTwitterButton()
}
}
When the button is pressed I call a delegate function in the MasterViewController which contains the following standard code for sharing on Twitter:
func touchedTwitterButton() {
var shareToTwitter :SLComposeViewController = SLComposeViewController(forServiceType: SLServiceTypeTwitter)
self.presentViewController(shareToTwitter, animated: true, completion: nil)
}
I receive the error :
"Attempt to present ViewController whose view is not in the window hierarchy!".
I've tried several workarounds. For example, creating a separate view controller and performing a segue from the button. That works in part, however, when I try to pass data I get another error :
"'NSInvalidArgumentException', reason: Receiver ViewController has no segue with identifier 'segueToTwitterShare'".
Which isn't true. For this I tried deleting my app and restarting xcode which worked for some people. However, the problem persists.
let touchDelegateForShotsCell: TouchDelegateForShotsCell = MasterViewController()
It's not the good delegate. When you write MasterViewController() you create a new instance of MasterViewController (so it is not in the window hierarchy) but you don't pass the intense who is executed.
I suggest you an example to better understand what is the problem and see where changes is needed.
I add an init() function into ShotsCell :
class ShotsCell : UITableViewCell {
var touchDelegateForShotsCell: TouchDelegateForShotsCell!
init(withDelegate delegate: MasterViewController){
super.init(style: UITableViewCellStyle.Default, reuseIdentifier: "cellIdentifier")
touchDelegateForShotsCell = delegate
}
#IBAction func twitterButtonPressed(sender: AnyObject) {
touchDelegateForShotsCell.touchedTwitterButton()
}
}
And pass your MasterViewController to your cell in cellForRowAtIndexPath :
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = ShotsCell(withDelegate: self)
return cell
}
Hope that helps. It works for me.
I have a view in my app called JournalViewController that I'm presenting over my PastSessionsViewController. PastSessions has a table view that the user can tap to edit and bring up the journal.
When the user edits an entry and saves it (saving to CoreData), dismissing JournalViewController I'd like for the table view in PastSessions to reflect those changes and show the updated table cell.
I'm calling tableView.reloadData() in PastSessionsViewController viewDidLoad() but that doesn't seem to be working. I've also added a delegate for JournalViewController to interact with PastSessionsViewController ahead of dismissViewController
Here's some code to look at:
In PastSessionsViewController:
class PastSessionsViewController: UIViewController, UITableViewDelegate, JournalVCDelegate {
weak var tableView: UITableView?
weak var backButton: UIButton?
let pastSessionsDataSource: PastSessionsDataSource
init() {
pastSessionsDataSource = PastSessionsDataSource()
super.init(nibName: nil, bundle: nil)
}
required init(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func viewDidLoad() {
super.viewDidLoad()
let tableView = UITableView()
tableView.backgroundColor = nil
tableView.delegate = self
tableView.dataSource = pastSessionsDataSource
tableView.registerClass(EntryCell.self, forCellReuseIdentifier: "cell")
view.addSubview(tableView)
self.tableView = tableView
}
override func viewDidAppear(animated: Bool) {
tableView?.reloadData()
}
func didFinishJournalVC(controller: JournalViewController) {
var newDataSource = PastSessionsDataSource()
tableView?.dataSource = newDataSource
// tried this ^, but it's causing the app to crash
// tableView?.reloadData() <- this isn't doing the trick either
dismissViewControllerAnimated(true, completion: nil)
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
let editJournalVC = JournalViewController(label: "Edit your thoughts")
editJournalVC.delegate = self
presentViewController(editJournalVC, animated: true, completion: nil)
}
}
In JournalViewController:
protocol JournalVCDelegate {
func didFinishJournalVC(controller: JournalViewController)
}
class JournalViewController: UIViewController, UITextViewDelegate {
var delegate: JournalVCDelegate! = nil
func doneJournalEntry(sender: UIButton) {
journalEntryTextArea?.resignFirstResponder()
... do some core data saving ...
delegate.didFinishJournalVC(self)
}
}
In PastSessionsDataSource:
import UIKit
import CoreData
class PastSessionsDataSource: NSObject {
var arrayOfEntries = [Entry]()
var coreDataReturn: [Meditation]?
func prepareEntries() {
// gets stuff from coredata and formats it appropriately
}
override init() {
super.init()
prepareEntries()
}
}
extension PastSessionsDataSource: UITableViewDataSource {
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return arrayOfEntries.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! EntryCell
... set up the labels in the cell ...
return cell
}
}
Thanks for looking!
viewDidLoad is called when the view controller load its view at the first time, so basically it will only be called once during the view controller's whole life cycle.
One quick solution is to put tableView.reloadData() in PastSessionsViewController viewWillAppear() or viewDidAppear().
However I do not like this quick solution as every time you dismiss JournalViewController, the table view will be reloaded, even the user has not changed anything on JournalViewController (for example, cancel the edit). So I suggest to use delegate approach between PastSessionsViewController and JournalViewController, when the user actually edit the data on JournalViewController then inform PastSessionsViewController to refresh the table.
You are currently prepare entries only on init of PastSessionsDataSource, but not after you did CoreData changes. So each time when you reloadData for tableView you work with the same data set loaded initially. As a quick hack you can try to updated viewDidAppear in a following way:
override func viewDidAppear(animated: Bool) {
if let tableView = tableView {
let dataSource = tableView.dataSource! as PastSessionsDataSource
dataSource.prepareEntries()
tableView.reloadData()
}
}
Your tableView property is probably nil in viewDidAppear, based on your listed code. The reason is that in viewDidLoad you construct a UITableView as tableView, and that is a local variable. You need to assign that variable to the property:
self.tableView = tableView