Get IndexPath of CollectionViewCell outside of Cell

Question

First of all I am a newbie in swift, so be gentle. I have a problem fetching the indexPath of the cell outside of the cell. I want to get that index path to a function and use it to send the content to another view. The image was created programatically in the cell, it has a tap gesture recogniser sending to this function (where "myIndex" is defined as an Int : var myIndex = 0):

// tap image to go at the indexpath of the user
func imageTapped(tapGestureRecognizer: UITapGestureRecognizer) {
   print("image tapped")

    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let secondViewController = storyboard.instantiateViewController(withIdentifier: "patientProfile") as! PatientProfileVC
    secondViewController.userID = posts[myIndex].userID
    secondViewController.patientName = posts[myIndex].author

    print("Passed data to the other view")

    self.show(secondViewController, sender: self)


}

I know that I could use didSelectItem at IndexPath where I also have the declaration of the myIndex but I have something that will be triggered from a segue there:

//standard functon for item selected
override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {

    //get the index of the cell
    myIndex = indexPath.row

    print("Cell is selected")

    //perform the segue
    self.performSegue(withIdentifier: "CommentsVC", sender: self)
    print(myIndex)

}

and my perform for segue looks like this:` override

func prepare(for segue: UIStoryboardSegue, sender: Any?) {

    print("Segue Initiated")
    feed.navigationItem.title = nil

    //if segue.destination is CommentsFullVC{
        print("Comments segue initiated")
        let secondViewController = segue.destination as! CommentsFullVC
        secondViewController.questionData = posts[myIndex].postContent
        secondViewController.authorName = posts[myIndex].author
        secondViewController.date = posts[myIndex].normalDate
        secondViewController.profileImagePath = posts[myIndex].pathToImage
        secondViewController.typeOfClinic = posts[myIndex].clinic
        secondViewController.postID = posts[myIndex].postID
        secondViewController.followersForPost = posts[myIndex].followers

}

So my question is, how do I pass those 2 fields to the other view without using prepareForSegue? I am struggling with this for 20 hours now and still can not figure it out.

secondViewController.userID = posts[myIndex].userID
secondViewController.patientName = posts[myIndex].author

UPDATE: Got it to work thanks to Jose answer, now it looks like this... in case anybody has the same problem as I had.

 // tap image to go at the indexpath of the user
func imageTapped(tapGestureRecognizer: UITapGestureRecognizer) {
   print("image tapped")


    let pointInCollectionView = tapGestureRecognizer.location(in: collectionView)
    let indexPath = collectionView?.indexPathForItem(at: pointInCollectionView)
    print(indexPath!)

    // this one works - show segue
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let secondViewController = storyboard.instantiateViewController(withIdentifier: "patientProfile") as! PatientProfileVC
    secondViewController.userID = posts[(indexPath?.row)!].userID
    secondViewController.patientName = posts[(indexPath?.row)!].author

    print("Passed data to the other view")

    self.show(secondViewController, sender: self)


}

can you explain what is wrong with `didSelectItemAt `? It looks ok — JuicyFruit, Jun 03 '17 at 13:34
With that part is ok, nothing wrong. I just can not implement a second segue as it dosen't exists in the storyboard. It dosen't have a segue identifier. I can not compare them in a if statement, or I don't know how if it is a possibility. Reason why I am implementing it in the: imageTapped function. It goes to the PatientProfileVC, but it taxes the default value of: myIndex witch is 0 so it shows the details that I am asking only for the first row of the collectionView. Thats why I am trying to get the indexPath somehow into the imageTapped function @JuicyFruit — Marian Petrisor, Jun 03 '17 at 14:09
It's about the second segue from the imageTapped function where I have the problem. — Marian Petrisor, Jun 03 '17 at 14:11

score 4 · Accepted Answer · answered Jun 03 '17 at 14:39

4

Get the location of the tapGestureRecognizer in the collectionView and then the indexPath at the given location

let pointInCollectionView = tapGestureRecognizer.location(in: collectionView)
let indexPath = collectionView.indexPathForItem(at: pointInCollectionView)

answered Jun 03 '17 at 14:39

Jože Ws

1,754
17
12

Thanks @Joze, it works like a charm! You deserve a pint for this! – Marian Petrisor Jun 03 '17 at 15:16

score 1 · Answer 2 · answered Jun 03 '17 at 15:28

I think this will be easy with a Delegate of the cell but its a little bit complicated.

The easy answer should be to store the index in the "tag" property of the imageView of the tapped image then extract from the gestureRecognizer You can add a tag where you create the imageView and the code where you recover the tag will look like this:

func imageTapped(tapGestureRecognizer: UITapGestureRecognizer) {
    print("image tapped")
    var myIndex = 0
    if let imageView = tapGestureRecognizer.view {
        myIndex = imageView.tag
    }

    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let secondViewController = storyboard.instantiateViewController(withIdentifier: "patientProfile") as! PatientProfileVC
    secondViewController.userID = posts[myIndex].userID
    secondViewController.patientName = posts[myIndex].author

    print("Passed data to the other view")

    self.show(secondViewController, sender: self)


}

This would have also been a good fix! Thanks anyway, I managed to solve it taking the location of the Tap gesture recogniser in the collection view. — Marian Petrisor, Jun 03 '17 at 16:15

score 0 · Answer 3 · answered Jun 03 '17 at 14:48

If your code write like below like then try this

collection view cell for row Method

cell.image = indexPath.row
let tap = UITapGestureRecognizer.init(target: self, action: #selector(imageTapped(_:)))
tap.accessibilityElements = [indexPath]
cell.image.addGestureRecognizer(tap)

Your function out side of collection view

func imageTapped (_ sender:UITapGestureRecognizer) {
     let index = sender.accessibilityElements?.first as! IndexPath   
     print(index.row)
     myIndex = index.row
}

Get IndexPath of CollectionViewCell outside of Cell

3 Answers3