hmlongco

struct ParentView: View {
    @State var id = UUID().uuidString
    var body: some View {
        VStack(spacing: 20) {
            VStack {
                Text("Parent View")
                Text(id).font(.footnote)
            }
            ChildView(name: "Child Maintains State On Update")
            ChildView(name: "Child Loses State On Update")

hmlongco

import SwiftUI

class ContentModel: ObservableObject {
    @Published var count: Int = 0
    let items10 = (0 ..< 10).map { Item(id: $0 + 1) }
    let items100 = (0 ..< 100).map { Item(id: $0 + 1) }
    let items10K = (0 ..< 10_000).map { Item(id: $0 + 1) }
    let items100K = (0 ..< 100_000).map { Item(id: $0 + 1) }
}

hmlongco

// Classic 

class ShopViewModel: ObservableObject {
    @Published private(set) var products: [Products]
    init(products: [Products] = []) {
        self.products = products
    }
    public func add(product) {
        products.append(product)
    }

hmlongco

    
class DeinitTracker {}

class Test {
    init() {}
    
    #if DEBUG
    lazy var deinitTracker: DeinitTracker? = DeinitTracker()
    #endif
}

hmlongco

extension Binding {
    public func defaultValue<T>(_ value: T) -> Binding<T> where Value == Optional<T> {
        Binding<T> {
            wrappedValue ?? value
        } set: {
            wrappedValue = $0
        }
    }
}

hmlongco

extension Binding {
    public static func variable(_ value: Value) -> Binding<Value> {
        var state = value
        return Binding<Value> {
            state
        } set: {
            state = $0
        }
    }
}

hmlongco

let tableViewDataSource = users
    .filter { $0.age > 21 && $0.name != "Simon" && $0.phone.contains("iPhone") }
    .map { ViewModel(cellTitle: $0.name, cellSubtitle: $0.phone) }

hmlongco

class RingEditViewModel: ObservableObject {

    @NestedObservableObject var ring: RingData

    private let isEditing: Bool
    private let temporaryContext: NSManagedObjectContext

    init(context: NSManagedObjectContext, ring: RingData? = nil) {
        self.temporaryContext = context.child()
        if let ring = temporaryContext.copy(of: ring) {

hmlongco

//
//  Combine+Extensions.swift
//  Common
//
//  Created by Michael Long on 8/27/22.
//

import Foundation
import Combine

hmlongco

struct ToDo: Codable, Identifiable {
    let id: Int
    let userId: Int
    var title: String
    var completed: Bool
}

class SelectionManager<Item: Identifiable>: ObservableObject {
    @Published var status: [Item.ID:Bool] = [:]
    func isSelected(_ item: Item) -> Bool {