RuiAAPeres

SwiftUI best practise

This doc distills layout and scrolling guidance from Fatbobman SwiftUI articles. It focuses on layout, sizing, alignment, stacks/grids, safe areas, overlays/backgrounds, and scrolling/lazy containers.

Layout fundamentals

• Learn the size pipeline (proposed size, required size, layout size, view size) so you know why frame and measuring can behave unexpectedly. Source: https://fatbobman.com/en/posts/layout-dimensions-1/
• Similar-looking layouts can have different layout semantics. Use frame and fixedSize with intent, and prefer the container that matches the layout contract you want. Source: https://fatbobman.com/en/posts/layout-dimensions-2/
• Use the simplest layout tool that meets the requirement: offset, alignmentGuide, layoutPriority, and ScrollView can all solve the same UI, but they affect layout differently. Source: https://fatbobman.com/en/posts/layout-in-swiftui-way/
• Centering can be done via Spacer, frame(alignment:), overlay, or GeometryReader.

RuiAAPeres

          Task { @MainActor in

          }

RuiAAPeres

// let base = [1,2,4,6,5,8,6]
// let filtered = base.takeUntil{ $0.isMultiple(of: 2) } // [2,4,6]
//
// let base = [2,4,6,5,8,6]
// let filtered = base.takeUntil{ $0.isMultiple(of: 2) } // [2,4,6]
//
// It stops collecting when the predicate fails (5,8,6 are not evaluated)
//
// Idea by https://twitter.com/K0nserv
//

RuiAAPeres

public typealias CompletionHandler = Function<Void, Void>
public typealias SideEffect<Input> = Function<Input, Void>

public struct Function<Input, Output>: Identifiable {

  public let id: String
  internal let f: (Input) -> Output

  public init(
      id: String,

RuiAAPeres

import ReactiveSwift
import XCTest

private let counterFailure: (Int, Int) -> String = { count, maxCount in
  return "Counter is currently at \(count) which higher than the max \(maxCount)"
}

private let timeoutFailure = "Expectation timeout"

private let infoTemplate: (String, String, Int) -> String = { fileName, functionName, lineNumber in

RuiAAPeres

/// This heavily based on the work done at RxGRDB

import GRDB
import ReactiveSwift

extension DatabasePool: ReactiveExtensionsProvider {}
extension DatabaseQueue: ReactiveExtensionsProvider {}
extension ValueObservation: ReactiveExtensionsProvider {}
extension DatabaseRegionObservation: ReactiveExtensionsProvider {}

RuiAAPeres

import Foundation

@propertyWrapper struct Notifier<Value> {
  private let identifier: String

  var wrappedValue: Value? {
    didSet {
      NotificationCenter.default.post(name: Notification.Name(identifier), object: wrappedValue)
    }
  }

RuiAAPeres

public typealias CompletionHandler = Function<Void, Void>
public typealias SideEffect<Input> = Function<Input, Void>

public struct Function<Input, Output>: Identifiable {

  public let id: String
  internal let f: (Input) -> Output

  public init(
      id: String,

RuiAAPeres

/// |                    World                 |
/// |------------------------------------------|
/// | Module A | Module B | Module C | Module D|

1. World is a module
2. World is aware of all modules.
3. Modules aren't aware of World.

RuiAAPeres

import UIKit

public extension UIColor {

  var components: (red: CGFloat, green: CGFloat, blue: CGFloat, alpha: CGFloat) {
      var red: CGFloat = 0
      var green: CGFloat = 0
      var blue: CGFloat = 0
      var alpha: CGFloat = 0