Sorting data by Newest and Oldest - swiftui

Question

I want to sort my custom array by the last tapped(Newest). I can sort by name or by id, but I have trouble sorting by time. I couldn't find similar issues on the internet, and it gives me a lot of headaches. As you can see in my code below, I want to sort the favorite list by the last tapped. Thanks in advance for your help.
import Foundation
import SwiftUI
struct DataArray: Identifiable {
let id: Int
let cities: String
let name1: String
let name2: String
let isFavorite: Bool
var date = Date()
}
public struct ListDataArray {
static let dot = [
DataArray(id: 1,
cities: "Baltimore"
name1: "John",
name2: "Mike",
isFavorite: False),
DataArray(id: 2,
cities: "Frederick"),
name1: "Joe",
name2: "Swift",
isFavorite: False),
DataArray(id: 3,
cities: "Catonsville"
name1: "Susan",
name2: "Oliver",
isFavorite: False),
// There will be a lot of data
]
}
class Prospect: ObservableObject {
#Published var datas: [DataArray] = []
init() {
fetchDataArrays()
}
private func fetchDataArrays() {
let items = ListDataArray.dot
datas = items
}
// To View Favorite
#Published var showFavorite: Bool = false
}
struct Home: View {
#EnvironmentObject var items: Prospect
var body: some View {
ScrollView {
LazyVStack {
ForEach(items.datas) { data in
VStack {
ButtonView(data: data)
.environmentObject(items)
Text("\(data.id)")
.font(.title3)
Text(data.cities)
.font(.subheadline)
Text(data.name1)
.font(.subheadline)
Text(data.name2)
.font(.subheadline)
}
padding()
}
.padding()
}
}
}
}
struct ButtonView: View {
#EnvironmentObject var items: Prospect
let data: DataArray
var index: Int {
items.datas.firstIndex(where: { $0.id == data.id }) ?? 0
}
var body: some View {
HStack {
Button(action: {
self.items.datas[self.index].isFavorite.toggle()
} label: {
Image(systemName: self.items.datas[self.index].isFavorite ? "suit.heart.fill" : "suit.heart").padding()
})
Spacer()
Button(action: {
items.showFavorite.toggle()
} label: {
Image(systemName: "person").padding()
})
.sheet(isPresented: $items.showFavorite) {
FavoriteView()
.environmentObject(items)
}
}
}
}
struct FavoriteView: View {
#EnvironmentObject var items: Prospect
#State var selection = 0
let sortingNames = ["Newest", "Oldest", "A to Z", "Z to A"]
var body: some View {
VStack {
HStack {
ForEach(0...<4) { num in
Button(action: {
selection = num
}, label: {
Spacer()
Text(sortingNames[num])
.forgroundColor(selection == num ? Color.blue: Color.black)
Spacer()
})
}
}
List {
ForEach(sorting()) { data in
if data.isFavorite {
VStack(spacing: 10) {
Text(data.cities)
Text(data.name1)
Text(data.name2)
}
.font(.body)
}
}
.padding()
}
Spacer()
}
}
private func sorting() -> [DataArray] {
switch selection {
case 0:
// Here I want to sort by the Newest...
return items.datas.sorted(by: { $0.date < $1.date })
case 1:
// Here I want to sort by the Oldest...
return items.datas.sorted(by: { $0.date < $1.date })
case 2:
return items.datas.sorted(by: { $0.cities < $1.cities })
case 3:
return items.datas.sorted(by: { $0.cities > $1.cities })
}
}
}
struct Home_Previews: PreviewProvider {
static var previews: some View {
Home()
.environmentObject(Prospect())
}
}

Answer 1

Focusing only on the sorting as per the question, the following works well for me.
The only significant change, was the sort by Oldest. Here is my test code:
import SwiftUI
#main
struct TestApp: App {
var body: some Scene {
WindowGroup {
ContentView()
}
}
}
struct DataArray: Identifiable {
let id: Int
let cities: String
let name1: String
let name2: String
let isFavorite: Bool
var date = Date()
}
struct ContentView: View {
let dataArr = [DataArray(id: 1,cities: "Baltimore", name1: "John", name2: "Mike", isFavorite: true,
date: Date()),
DataArray(id: 2,cities: "Frederick" ,name1: "Joe", name2: "Swift", isFavorite: true,
date: .now+1),
DataArray(id: 3,cities: "Catonsville", name1: "Susan", name2: "Oliver", isFavorite: true,
date: .now+2)
]
#State var selection = 0
let sortingNames = ["Newest", "Oldest", "A to Z", "Z to A"]
var body: some View {
VStack {
HStack {
ForEach(0..<4) { num in
Button(action: { selection = num}) {
Text(sortingNames[num])
.foregroundColor(selection == num ? Color.blue: Color.black)
}
}
}
List {
ForEach(sorting()) { data in
if data.isFavorite {
VStack(spacing: 10) {
Text("\(data.id)").foregroundColor(.red) // <-- for testing
Text(data.cities)
Text(data.name1)
Text(data.name2)
}
}
}
}
}
}
func sorting() -> [DataArray] {
switch selection {
case 0:
// Here I want to sort by the Newest...
return dataArr.sorted(by: { $0.date < $1.date })
case 1:
// Here I want to sort by the Oldest...
return dataArr.sorted(by: { $0.date > $1.date }) // <--- here
case 2:
return dataArr.sorted(by: { $0.cities < $1.cities })
case 3:
return dataArr.sorted(by: { $0.cities > $1.cities })
default:
return dataArr // <--- here need a default
}
}
}
EDIT1:
Since I don't know what you really want to do with your app,
I just modified your (test) code to show you an approach for getting your data sorted.
The main emphasis here is to have
one source of truth of the data, starting in ContenView #StateObject var items = Prospect().
Also made sorting() sorting the data in-place, so that it appear sorted everywhere.
Moved sorting() into your Prospect model.
I also renamed the badly named DataArray to CityData.
struct ContentView: View {
#StateObject var items = Prospect()
var body: some View {
Home().environmentObject(items)
}
}
struct Home: View {
#EnvironmentObject var items: Prospect
var body: some View {
ScrollView {
LazyVStack {
ForEach(items.datas) { data in
VStack {
ButtonView(data: data)
Text("\(data.id)").font(.title3)
Text(data.cities).font(.subheadline)
Text(data.name1).font(.subheadline)
Text(data.name2).font(.subheadline)
}.padding()
}.padding()
}
}
}
}
struct ButtonView: View {
#EnvironmentObject var items: Prospect
#State var data: CityData // <--- here
#State var index: Int = 0 // <--- here
var body: some View {
HStack {
Button(action: { items.datas[index].isFavorite.toggle() }) {
Image(systemName: items.datas[index].isFavorite ? "suit.heart.fill" : "suit.heart").padding()
}
Spacer()
Button(action: { items.showFavorite.toggle() }) {
Image(systemName: "person").padding()
}
}
.onAppear {
if let ndx = items.datas.firstIndex(where: { $0.id == data.id }) {
index = ndx
}
}
.sheet(isPresented: $items.showFavorite) {
FavoriteView().environmentObject(items)
}
}
}
struct FavoriteView: View {
#Environment(\.dismiss) var dismiss
#EnvironmentObject var items: Prospect
#State var selection = 0
let sortingNames = ["Newest", "Oldest", "A to Z", "Z to A"]
var body: some View {
VStack {
Button(action: {dismiss()}) {
Text("Done").foregroundColor(.blue) // <-- for testing on macos
}
HStack {
ForEach(0..<4) { num in
Button(action: {
selection = num
items.sorting(selection) // <--- here
}) {
Text(sortingNames[num])
.foregroundColor(selection == num ? Color.blue: Color.black)
}
}
}
List {
ForEach(items.datas) { data in // <--- here
if data.isFavorite {
VStack(spacing: 10) {
Text("\(data.id)").foregroundColor(.red) // <-- for testing
Text(data.cities)
Text(data.name1)
Text(data.name2)
}
}
}
}
}
}
}
class Prospect: ObservableObject {
#Published var datas: [CityData] = []
#Published var showFavorite: Bool = false
init() {
fetchCityDatas()
}
private func fetchCityDatas() {
datas = ListCityData.dot
}
// --- sort in place note sort() not sorted() ---
func sorting(_ selection: Int) {
switch selection {
case 0:
// Here I want to sort by the Newest...
datas.sort(by: { $0.date < $1.date })
case 1:
// Here I want to sort by the Oldest...
datas.sort(by: { $0.date > $1.date }) // <--- here
case 2:
datas.sort(by: { $0.cities < $1.cities })
case 3:
datas.sort(by: { $0.cities > $1.cities })
default:
break
}
}
}
public struct ListCityData {
static let dot = [CityData(id: 1,cities: "Baltimore", name1: "John", name2: "Mike", isFavorite: true,
date: .now),
CityData(id: 2,cities: "Frederick" ,name1: "Joe", name2: "Swift", isFavorite: true,
date: .now+10),
CityData(id: 3,cities: "Catonsville", name1: "Susan", name2: "Oliver", isFavorite: true,
date: .now+20)
]
}
// --- here renamed and using var ---
struct CityData: Identifiable {
let id: Int
var cities: String
var name1: String
var name2: String
var isFavorite: Bool
var date: Date
}