Push segue from UITableViewCell to ViewController in Swift

Question

I'm encountering problems with my UITableViewCells. I connected my UITableView to a API to populate my cells.

Then I've created a function which grabs the indexPath.row to identify which JSON-object inside the array that should be sent to the RestaurantViewController.

Link to my Xcode Project for easier debugging and problem-solving

Here's how my small snippet looks for setting the "row-clicks" to a global variable.

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
     i = indexPath.row
}

And here's my prepareForSegue() function that should hook up my push-segue to the RestaurantViewController.

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
    if segue.identifier == "toRestaurant"{
    let navigationController = segue.destinationViewController as UINavigationController
    let vc = navigationController.topViewController as RestaurantViewController
    vc.data = currentResponse[i] as NSArray
 }
}

And here's how I've set up my segue from the UITableViewCell

Here's my result, I've tried to click every single one of these cells but I won't be pushed to another viewController...I also don't get an error. What is wrong here?

Tried solutions that won't work

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
        if segue.identifier == "toRestaurant"{
            let vc = segue.destinationViewController as RestaurantViewController
            //let vc = navigationController.topViewController as RestaurantViewController
            vc.data = currentResponse[i] as NSArray
        }
    }

Answer 1

The problem is that you're not handling your data correctly. If you look into your currentResponse Array, you'll see that it holds NSDictionaries but in your prepareForSegue you try to cast a NSDictionary to a NSArray, which will make the app crash.

Change the data variable in RestaurantViewController to a NSDictionary and change your prepareForSegue to pass a a NSDictionary

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
    if let cell = sender as? UITableViewCell {
        let i = redditListTableView.indexPathForCell(cell)!.row
        if segue.identifier == "toRestaurant" {
            let vc = segue.destinationViewController as RestaurantViewController
            vc.data = currentResponse[i] as NSDictionary
        }
    }
}  

For Swift 5

func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
        if let cell = sender as? UITableViewCell {
            let i = self.tableView.indexPath(for: cell)!.row
            if segue.identifier == "toRestaurant" {
                let vc = segue.destination as! RestaurantViewController
                vc.data = currentResponse[i] as NSDictionary
            }
        }
    }

Answer 2

The following steps should fix your problem. If not, please let me know.

1. Remove your tableView(tableView, didSelectRowAtIndexPath:) implementation.

2. Make data on RestaurantViewController have type NSDictionary!

3. Determine the selected row in prepareForSegue:

   override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
       if let cell = sender as? UITableViewCell {
           let i = tableView.indexPathForCell(cell)!.row
           if segue.identifier == "toRestaurant" {
               let vc = segue.destinationViewController as RestaurantViewController
               vc.data = currentResponse[i] as NSDictionary
           }
       }
   }
   

Answer 3

Dropbox link to stack3 directory

1. I am having difficulty understanding why your software is much different than a standard 2 level tableview structure. So I coded a short example which you can access from this link. I have also included the sources code below.

2. The program mimics what you have (as best as I understood it). Table Controller 1 segues to Table Controller 2 from the tableview cell. I had no issues with segue-ing. Notice that I do not have nor need to augment the Storybook to initiate the segue.

3. I have embedded both the controllers in Navigation Controllers. My experience is that it saves a lot of effort to set up the navigation.

4. Alternately, I could have control-dragged from the first TableViewController symbol on top of the screen to the second controller and set up the segue.

5. I used a global variable (selectedRow) although it is not a recommend practice. But you just as easily use the prepareForSegue to set a variable in the RestaurantTableViewController (I show an example)

   6. Finally, I recommend checking the Connections Inspector (for the table view cell in the first controller) to confirm that there is a segue to the second controller. If you control-dragged properly there should be confirmation prompt as well as an entry in the Connections Inspector.

Unfortunately I just cant get the code properly formatter

import UIKit

var selectedRow = -1

class TableViewController: UITableViewController {

var firstArray = ["Item1","Item2","Item3","Item4"]

override func viewDidLoad() {

super.viewDidLoad()

}

override func didReceiveMemoryWarning() {

super.didReceiveMemoryWarning()

}

// MARK: - Table view data source

override func numberOfSectionsInTableView(tableView: UITableView) -> Int {

return 1
}

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

return firstArray.count

}


let nameOfCell = "RestaurantCell"

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

let cell = tableView.dequeueReusableCellWithIdentifier(nameOfCell, forIndexPath: indexPath) as UITableViewCell

cell.textLabel!.text = firstArray[indexPath.row]

return cell

}

override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

selectedRow = indexPath.row

}

// MARK: - Navigation

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {

let vc = segue.destinationViewController as RestaurantTableViewController

// can write to variables in RestaurantTableViewController if required

vc.someVariable = selectedRow

}


}


import UIKit

class RestaurantTableViewController: UITableViewController {

var secondArray = ["Item 2.1", "Item 2.2", "Item 2.3", "Item 2.4"]

var someVariable = -1

override func viewDidLoad() {

super.viewDidLoad()

}

override func didReceiveMemoryWarning() {

super.didReceiveMemoryWarning()

}

// MARK: - Table view data source

override func numberOfSectionsInTableView(tableView: UITableView) -> Int {

return 1

}

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

return secondArray.count

}

let nameOfCell = "RestaurantCell"

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

let cell = tableView.dequeueReusableCellWithIdentifier(nameOfCell, forIndexPath: indexPath) as UITableViewCell

cell.textLabel!.text = secondArray[indexPath.row]

if indexPath.row == selectedRow {

cell.textLabel!.text = cell.textLabel!.text! + " SELECTED"

}

return cell

}

override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

selectedRow = indexPath.row

}

}

Answer 4

I noticed that in your screenshot of your storyboard, the segue is connecting the first prototype cell to the RestaurantViewController. This prototype cell looks like it's the "Basic" style of cell with a disclosure indicator accessory on the right. But look at the screenshot of your app running. The table is being populated with cells that appear to be the "Subtitle" style of cell without a disclosure indicator accessory on the right.

The reason that your segue is never firing no matter what you do is that the segue is only configured to work for a specific prototype cell, but that prototype cell is never being used when you populate the table. Whatever you're doing in tableView:cellForRowAtIndexPath:, you're not using the prototype cell that you want.

@Starscream has the right idea dequeueing the right cell with the right identifier and matching it with the identifier of the prototype cell in Interface Builder. The crash that you're getting even after doing that might be because of the previous problem mentioned in the comments above. Your segue in the storyboard is clearly pointing to a UITableViewController. Your code in prepareForSegue:sender: should be let vc = segue.destinationViewController as RestaurantViewController, as long as RestaurantViewController is a subclass of UITableViewController. You'll crash if you try to cast it as a UINavigationController. Also make sure that the class for the destination UITableViewController in the storyboard is listed as RestaurantController in the Identity Inspector pane. You'll crash if your program compiles thinking that the storyboard just contains a generic UITableViewController there.

Getting back to the original problem more, I don't know how you've implemented tableView:cellForRowAtIndexPath:, which might be crucial. Maybe it's not so simple. Maybe you plan on handling many prototype cells or generate custom cells at runtime. In this case, one way to make this simple for you is to programmatically perform the segue when the user taps on a cell. Instead of using a specific prototype cell, make the segue a connection originating from the "Restauranger nära mig" UITableViewController going to the RestaurantViewController. (Connect in Interface Builder by control-click dragging from the Table View Controller icon at the top of the first one over to the body of the second). You must give this segue an identifier in the Attributes Inspector pane to make this useful. Let's say it's "toRestaurant". Then at the end of your tableView:didSelectRowAtIndexPath: method, put this line of code: self.performSegueWithIdentifier("toRestaurant", sender: self). Now no matter what cell is selected in the table, this segue will always fire for you.