cellForRowAtIndexPath and numberOfRowsInSection conflicting in tableView - ios

Question

I am creating an app that is retrieving data from Firebase. In my 'MealViewController' I have a TableView that has the view controller as it's delegate and data source. I am getting the issue "Type 'MealViewController" does not conform to protocol 'UITableViewDataSource' because it requires both :numberOfRowsInSection: and :cellForRowAtIndexPath: . However, when I add both, another issue appears - 'Definition conflict with previous value'. I've looked through all the Stack Overflow issues related to this, and no luck has been had. Here's my View Controller:
class MealViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
var bgImage: UIImageView?
var image : UIImage = UIImage(named: "pizza")!
#IBOutlet weak var blurEffect: UIVisualEffectView!
#IBOutlet weak var mealTableView: UITableView!
var items = [MealItem]()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
bgImage = UIImageView(image: image)
bgImage?.contentMode = .ScaleAspectFill
bgImage!.frame = view.layer.bounds
self.view.addSubview(bgImage!)
//self.bgImage?.addSubview(blurEffect)
//bgImage!.bringSubviewToFront(blurEffect)
view.bringSubviewToFront(blurEffect)
mealTableView.layer.cornerRadius = 5.0
mealTableView.layer.borderColor = UIColor.whiteColor().CGColor
mealTableView.layer.borderWidth = 0.5
let ref = Firebase(url: "https://order-template.firebaseio.com/grocery-items")
mealTableView.delegate = self
mealTableView.dataSource = self
// MARK: UIViewController Lifecycle
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
print(items.count)
return items.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> MealsCellTableViewCell { //issue occurs here
let groceryItem = items[indexPath.row]
if let cell = mealTableView.dequeueReusableCellWithIdentifier("ItemCell") as? MealsCellTableViewCell {
cell.configureCell(groceryItem)
// Determine whether the cell is checked
self.mealTableView.reloadData()
return cell
}
}
func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
// [1] Call the queryOrderedByChild function to return a reference that queries by the "completed" property
ref.observeEventType(.Value, withBlock: { snapshot in
var newItems = [MealItem]()
for item in snapshot.children {
let mealItem = MealItem(snapshot: item as! FDataSnapshot)
newItems.append(mealItem)
}
self.items = newItems
self.mealTableView.reloadData()
})
}
func viewDidDisappear(animated: Bool) {
super.viewDidDisappear(animated)
}
func willAnimateRotationToInterfaceOrientation(toInterfaceOrientation: UIInterfaceOrientation, duration: NSTimeInterval) {
}
}
override func willAnimateRotationToInterfaceOrientation(toInterfaceOrientation: UIInterfaceOrientation, duration: NSTimeInterval) {
bgImage = UIImageView(image: image)
bgImage?.contentMode = .ScaleAspectFill
bgImage!.frame = view.layer.bounds
self.view.addSubview(bgImage!)
view.bringSubviewToFront(blurEffect)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: UITableView Delegate methods
}

Answer 1

The cellForRowAtIndexPath should look like this:
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cellIdentifier = "ItemCell"
let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath) as! MealsCellTableViewCell
let groceryItem = self.items[indexPath.row]
cell.configureCell(groceryItem)
return cell
}
Note that the returned cell is a MealsCellTableViewCell which is a subclass of UITableViewCell so it conforms to that class.
Don't change the function definition as that will make it not conform to what the delegate protocol specifies.
Here's a link to the Apple documentation for the specific implementation of custom tableView cells for reference.
Create a Table View

Answer 2

The problem is that your view controller's conformance to UITableViewDatasource cellForRowAtIndexPath method is not right. You should refactor your implementation of cellForRowAtIndexPath method like so:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let groceryItem = items[indexPath.row]
guard let cell = tableView.dequeueReusableCellWithIdentifier("ItemCell") as? MealsCellTableViewCell else {
fatalError("No cell with identifier: ItemCell")
}
cell.configureCell(groceryItem)
return cell
}
You also need to move the datasource methods out of viewDidLoad method.

Answer 3

You return MealsCellTableViewCell instead of UITableViewCell in cellForRowAtIndexPath method, that's the reason.