+/- quantity of products in Cart View Controller with buttons each on a TableViewCell, which gets default quantity as integer from an array

Question

i am developing an app that you could add items to the Cart from MenuVC, then you can go to CartVC to view what is on your cart and increase or decrease quantity of items to be ordered. I cant make quantity label to change, don't know if thats because i get quantity from an array? is it unmutable?

Thank you for your help

Here is my cell

import UIKit

class BasketCell: UITableViewCell {

@IBOutlet weak var quantityLabel: UILabel!
@IBOutlet weak var itemLabel: UILabel!
@IBOutlet weak var priceLabel: UILabel!

var buttonIncrease : ((UITableViewCell) -> Void)?
var buttonDecrease : ((UITableViewCell) -> Void)?

override func awakeFromNib() {
    super.awakeFromNib()
    // Initialization code
}

override func setSelected(_ selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)

    // Configure the view for the selected state
}


@IBAction func increaseQuantity(_ sender: Any) {
    buttonIncrease?(self)
}

@IBAction func decreaseQuantity(_ sender: Any) {
    buttonDecrease?(self)
}

here is my example 2d array which i append it from web service

var items = 
    [
        ["Cheeseburger","Pizza","Sprite","Redbull"],
        ["10 $","20 $","5 $","6 $"],
        [1,1,2,1,2]
    ]

and here is my cellForRowAt @CartVC

 func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView1.dequeueReusableCell(withIdentifier: "basketCell", for: indexPath) as! BasketCell

    cell.quantityLabel.text = String(items[2][indexPath.row] as! Int)

    cell.buttonIncrease = { (cell) in
        var quantity = self.items[2][indexPath.row] as! Int
        quantity += 1
        self.tableView1.reloadData()
    }
    cell.buttonDecrease = { (cell) in
        var quantity = self.items[2][indexPath.row] as! Int
        if quantity > 1 {
        quantity -= 1
        self.tableView1.reloadData()
        }
    }

    cell.itemLabel.text = items[0][indexPath.row] as? String
    cell.priceLabel.text = items[1][indexPath.row] as? String

    return cell
}

Unrelated but using an array of arrays for your data model is far from ideal. Define a `struct` with three properties for name, price, and quantity. Then have a single array of those structs. — rmaddy, Jan 01 '19 at 16:07

Robert Dresler · Accepted Answer · 2019-01-01T17:34:30.733

0

is it unmutable?

When you declare new variable by downcasting some element from array of Any objects, you get copy of this element which has no reference to element from array.

For your case would be better if you have your custom model

struct Item: Codable { // if you get this data from web service, you can use `JSONDecoder` to decode `Data` to `Item`/`[Item]`
    var title: String
    var price: String // better: `var price: Int` and then when you need to get text just add `" $"`
    var quantity: Int
}

then you can have your items array as array of Item objects

var items = [Item(title: "Cheeseburger", price: "10 $", quantity: 1), ...]

now you can get certain item from items in cellForRowAt as element from items with index equal to indexPath.row

let item = items[indexPath.row]
cell.quantityLabel.text = String(item.quantity)

And when you need to change it's amount property

self.items[indexPath.row].quantity += 1

edited Jan 01 '19 at 17:34

answered Jan 01 '19 at 16:07

Robert Dresler

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i am new to swift, how can i create that struct dynamically? i gave that array as example, i will get three types of elements from web service. how can i append them into that struct? – Doruk Çoban Jan 01 '19 at 17:12
@DorukÇoban What do you get from service? Title, price, quantity, etc.? – Robert Dresler Jan 01 '19 at 17:14
@DorukÇoban anyway, look to edited answer. You can implement `Encodable` and `Decodable` protocols to your struct: `struct Item: Codable` and then you can simply decode data from web service using `JSONDecoder` – Robert Dresler Jan 01 '19 at 17:16
title: String price: String quantity: Integer as json. i think i should search to extract data into struct since i cant change the value of array element – Doruk Çoban Jan 01 '19 at 17:33
@DorukÇoban look, now you have struct. Now learn something about `Codable`. There are lot of another questions about `Codable` protocol, so search... – Robert Dresler Jan 01 '19 at 17:35
eyeing some tutorials, it seems reliable in my case. thank you, – Doruk Çoban Jan 01 '19 at 17:39
@DorukÇoban Ok. Good luck! I hope my answer helped you little bit. – Robert Dresler Jan 01 '19 at 17:40
thank you so much, it worked. the reason i use 2d arrays commonly, i use them for creating sections – Doruk Çoban Jan 03 '19 at 15:12

+/- quantity of products in Cart View Controller with buttons each on a TableViewCell, which gets default quantity as integer from an array

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