Nested Array filter swift - ios

Question

I'm trying to filter the data from the sub_category array and show on the data in which isSelected is true. I have tried using flatmap and filter but am still not able to achieve the desired output. Please help.
{
"data": [
{
"category_name": "Social Sites",
"sub_category": [
{
"sub_category_name": "Instagram",
"isSelected" : true
},
{
"sub_category_name": "Facebook",
"isSelected" : true
},
{
"sub_category_name": "Twitter",
"isSelected" : false
}
]
},
{
"category_name": "",
"sub_category": [
{
"sub_category_name": "State",
"isSelected" : false
}
]
},
{
"category_name": "Sports",
"sub_category": [
{
"sub_category_name": "Cricket",
"isSelected" : true
},
{
"sub_category_name": "Hockey",
"isSelected" : false
}
]
}
]
}
Desired Output is only for isSelected = true
{
"data": [
{
"category_name": "Social Sites",
"sub_category": [
{
"sub_category_name": "Instagram",
"isSelected" : true
},
{
"sub_category_name": "Facebook",
"isSelected" : true
}
]
},
{
"category_name": "Sports",
"sub_category": [
{
"sub_category_name": "Cricket",
"isSelected" : true
}
]
}
]
}
I have tried using flatMap and filter, the following is my code.(But not able to achieve the desired output.)
let filtered = self.itemModelArray.flatMap { item in
item.subCategory!.filter({ (subCat) -> Bool in
subCat.isSelected == true
})
}
The above code gives me the array of subCategory,that is not what I want.
The following is my model
// MARK: - Item
struct Item: Codable {
let category_name: String
var sub_category: [SubCategory]
init(cat:String,subCat:[SubCategory]){
self.category_name = cat
self.sub_category = subCat
}
}
// MARK: - SubCategory
struct SubCategory: Codable {
let sub_category_name: String
var isSelected : Bool = false
init(subCat:String){
self.sub_category_name = subCat
}

Answer 1

Something like this would filter out both empty categories & non-selected sub-categories:
import Foundation
let json: String = <the json in the question, omited for brevity>
struct Model: Codable {
let data: [Category]
struct Category: Codable {
let category_name: String
let sub_category: [SubCategory]
}
struct SubCategory: Codable {
let sub_category_name: String
let isSelected: Bool
}
}
// Note: Handle any errors properly in production code
let model = try? JSONDecoder().decode(Model.self, from: Data(json.utf8))
var output: [Model.Category] = []
for category in model?.data ?? [] {
let selectedSubCategories = category.sub_category.filter(\.isSelected)
if !selectedSubCategories.isEmpty {
output.append(Model.Category(category_name: category.category_name, sub_category: selectedSubCategories))
}
}
which produces an array of 2 categories:
dump(output)
▿ 2 elements
▿ main.Model.Category
- category_name: "Social Sites"
▿ sub_category: 2 elements
▿ main.Model.SubCategory
- sub_category_name: "Instagram"
- isSelected: true
▿ main.Model.SubCategory
- sub_category_name: "Facebook"
- isSelected: true
▿ main.Model.Category
- category_name: "Sports"
▿ sub_category: 1 element
▿ main.Model.SubCategory
- sub_category_name: "Cricket"
- isSelected: true