Passing an array of structs from UICollectionView to DetailView and use the indexes to go from one item to another?

Question

I have a UICollectionView that is populated by an array of productItem structs, the struct blueprint is in it's own swift file called ProductoItem.swift

struct ProductoItem {
    let id: Int
    let name: String
    var price: String
    var picture: String
    var description: String
}

This works and I can successfully populate my UICollectionView with it, what I want to do now is to pass this struct to a detailView so I create this variable in the detailView.

var productos = [ProductoItem]()

And I put the following code in my prepareForSegue Method.

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "detalleProducto" {

        let controller = segue.destination as! ProductoDetailViewController

        controller.productos = productos
    }
}

What I don't know how to do know is:

First as we are sending the entire array of structs I want to pass the values stored on the CollectionView cell's index to the DetailView to populate it using just the data of the product's cell, then I also want to have two buttons to go to the next / prev product that just go to the next / prev index value of my struct. How can I do this?

Answer 1

First, create a new 'currentIndex: Int' attribute in your detailView.

From your first UIViewController (the one that has the UICollectionView), pass the current index and the array to your DetailView:

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "detalleProducto" {
        let controller = segue.destination as! ProductoDetailViewController
        controller.productos = productos

        // do whatever you need to get your index
        controller.currentIndex = self.collectionView.indexPathsForSelectedItems()[0].row
    }
}

Then in your DetailView, you have your array and the current index, so you can just get the info of this specific product by doing:

let currentProduct = self.productos[currentIndex]

To get to the previous or next one, you can just increment or decrement 'currentIndex'.