Unable to filter Json array to Show in tableview in swift

Question

Json response like this

{
"categories": [
    {
        "id": 48,
   
        "products": [
            {
                "name": ".Tea",
                "food_type": "veg",

Code: with this code i am able to show all first category products in tableview.. here if i click vegSwitch i need to show only "food_type": "veg" related products in tableview

 class FoodsMenuVC: UIViewController, UITableViewDelegate, UITableViewDataSource {

@IBOutlet weak var vegSwitch: UISwitch!
var foodType: String = ""
var filterArray: : Category?
var categoryArray: Category?
private var catData: Categories? {
    didSet{
     
        categoryArray = catData?.categories?[0]

        DispatchQueue.main.async {
            self.tableView.reloadData()
        }
    }
}

@IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
    super.viewDidLoad()

    foodMenuServicecall()
}

@IBAction func vegSwitch(_ sender: UISwitch) {
    
    if sender.isOn{
        filterArray = categoryArray?.products?.filter { $0.foodType?.rawValue == "veg" }
    }
    else{
    }
}

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return categoryArray?.products?.count ?? 0
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    
    let cell = tableView.dequeueReusableCell(withIdentifier: "FoodIteamsCell", for: indexPath) as! FoodIteamsCell
    cell.selectionStyle = .none
    
    if let eachCat = categoryArray{
        
        cell.nameLbl.text = eachCat.products?[indexPath.row].name?.capitalized
        
        for oneImg in eachCat.products?[indexPath.row].images ?? []{
            cell.iteamImg.sd_setImage(with: URL(string: oneImg.url ?? ""), placeholderImage: UIImage(named: "placeholder.png"))
        }
    }
    return cell
}
}

if i try like this in vegSwitch button filterArray = categoryArray?.products?.filter { $0.foodType?.rawValue == "veg" }

error:

Cannot assign value of type '[Product]?' to type 'Category?'

please guide me to filter JSON

You are filtering category?.products which returns an array of products which is of type [Product]?. This cannot be assigned to filterArray since its type is Category?. — Asteroid
– Asteroid, Commented Mar 3, 2022 at 15:57

Larme · Accepted Answer · 2022-03-03 15:55:20Z

0

Let's analyze:

You have:

var filterArray: : Category?
var categoryArray: Category?

Then, you do:

filterArray = categoryArray?.products?.filter { $0.foodType?.rawValue == "veg" }

Which is equivalent, once "broken into multiple statements":

let products: [Product]? = categoryArray?.products
let filtered: [Product] = products?.filter { $0.foodType?.rawValue == "veg" }
filterArray = filtered //Here it fails, because `filterArray` is a Category and filtered a `[Product]`

So the solution would be to have extra method to Category:

extension Category {
    static func make(fromCategory category: Category, withProducts products: [Product]) -> Category {
        return Category(id: category.id, products: products)
    }
}

I use only id & products properties, since I don't know if there are more, but add them if needed.

Then, now, you can construct a Category that you can build from existing Category & filtered products.

In use:

let filterArray = categoryArray.compactMap { aCategory -> Category? in
    let filteredProducts = aCategory.products.filter { $0.foodType == "veg" }
    if filteredProducts.isEmpty {
        return nil // or Category.make(fromCategory: aCategory, withProducts: []), or just ignore the if test if it's fine to have a section category without products
    }
    return Category.make(fromCategory: aCategory, withProducts: filteredProducts)
}

But, according to your code, you don't seem to use Category, so get rid of it, and just use an array of products directly.

edited Mar 3, 2022 at 15:55

answered Mar 3, 2022 at 15:42

Larme

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8 Comments

Json Swift Over a year ago

cant we do filter without using extension Category... i am learnig swift codes.. for me above code is hard to understand... could you make it easy please... with that extension i donno how to show tableview

Larme Over a year ago

Put make(fromCategory:withProduct) inside struct Category, there is not need for a category in reality.

Json Swift Over a year ago

in my code how to do filter with food_type for products in categories.. and show in tableview

Larme Over a year ago

I've shown how to replace filterArray = categoryArray?.products?.filter { $0.foodType?.rawValue == "veg" } with let filterArray = categoryArray.compactMap , it doesn't work?

Json Swift Over a year ago

i couldn't understand where to replace

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