Seguing from uicollectionview that is inside of a tableview - swift

Question

I've put a uicollectionview inside of a uitableview. I'm having trouble seguing to another viewcontroller after selecting a collectionview cell that is inside of the table view cell.
// if the user selects a cell, navigate to the viewcontroller
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// we check did cell exists or did we pressed a cell
if let cell = sender as? UICollectionViewCell {
let cell2 = tableView.dequeueReusableCell(withIdentifier: "cell") as! TestingTableView
// define index to later on pass exact guest user related info
let index = cell2.collectionView?.indexPath(for: cell)!.row
print(index as Any)
// if segue is guest...
if segue.identifier == "guest" {
// call guestvc to access guest var
let guestvc = segue.destination as! GuestCommunityViewVC
// assign guest user inf to guest var
guestvc.guest = communities[index!] as! NSDictionary
}
}
}
}
I'm getting an error at the line:
let index = cell2.collectionView?.indexPath(for: cell)!.row
because it is saying the value is nil. Does anyone know a better method to do this?

Answer 1

Here is an example of how to use a delegate:
1) Create a protocol outside of a class declaration:
protocol customProtocolName:class {
func pushToNewView(withData:[DataType])
}
note: use class in order to prevent a reference cycle
2) Create a delegate inside of the UITableViewCell that holds the reference to the UICollectionView:
class customUITableViewCell {
weak var delegate:customProtocolName? = nil
}
3) Inside the UIViewController that holds the reference to the UITableView, make sure you add the protocol besides the class declaration and add the function we created to ensure that the protocol specifications are satisfied:
class customViewController: customProtocolName {
func pushToNewView(withData:[DataType]) {
//inside here is where you will write the code to trigger the segue to the desired new UIViewController
//You can take this new data and store it in this ViewController and then during the segue pass it along
}
}
4) In the UITableViewDelegate function, "cellForRowAt", set the delegate inside the customUITableViewCell to self:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "customCell", for: indexPath) as! customUITableViewCell
cell.delegate = self
return cell
}
5) Inside the customUITableViewCell, where the UICollectionView delegate function handles "didSelectItemAt" delegate function, you trigger the protocol function there like so:
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
delegate?.pushToNewView(withData:[DataType])
}
This is a very simplified example, if you wanted to pass an IndexPath, then you can modify the function to do so. you can also pass back anything you want as well, it isn't limited.