Winchariot

//Phone model is not provided officially by any Cocoa API. 
//It can be narrowed down to a few different models by checking the screen dimensions, but this shouldn't be relied upon
//  and should NEVER drive any business logic.
//A good use for such knowledge is for something like error logging.
//https://www.paintcodeapp.com/news/ultimate-guide-to-iphone-resolutions
static var iPhoneModel: String? {
    guard UIDevice().userInterfaceIdiom == .phone else { return nil }

    switch UIScreen.main.nativeBounds.height {
    case 1136:

Winchariot

#if using Cocoapods
Pods/

#if using bundler to manage Cocoapods version
.bundle
vendor/

.DS_Store
.idea
*.swp

Winchariot

lazy var accessoryToolbarWithDoneButton: UIToolbar = {

    let toolbar = UIToolbar(frame: CGRect.zero)
    //only needs to be flexible in the dimension(s) you want it to be
    //https://stackoverflow.com/questions/31822504/how-can-i-increase-the-height-of-an-inputaccessoryview
    toolbar.autoresizingMask = [.flexibleWidth, .flexibleHeight] 
    
    let leftSpace = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
    let doneButton = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(keyboardDoneButtonTapped(_:)))
    toolbar.items = [leftSpace, doneButton]

Winchariot

import UIKit

//I represent a screen in my app that is relatively complicated. Suppose I'm a sort of scrollable activity feed in a financial app;
//  I may have sections for balances, alerts, recent activity, credit score, a financial checkup quiz, etc.
//  Separating those sections into their own child VCs is great for splitting up the workload and separating the code.
//  Then I, the parent VC, can easily compose my feed using any subset of these child VCs and in any order using view controller containment.

class CompositeViewController: UIViewController {

  private let scrollView: UIView?

Winchariot

//I am some 3P service. I can be asked for many different types of values.
class ValueMaker {
    static func makeBool() -> Bool { return true }
    static func makeInt() -> Int { return 3 }
}

//I am a 1P abstraction over that service. 
//  I want to save effort in the rest of my codebase by exposing 1 func for getting values, 
//  instead of needing a different func for each possible type our 3P service can vend. So I use a func with a generic return type.
func genericMaker<T: TypeEmittedByOur3PService>() -> T? {

Winchariot

//Both implementations thanks to https://useyourloaf.com/blog/how-to-percent-encode-a-url-string/
//Upgraded/cleaned up for Swift 4

Extension String {
    func percentEncodedForRFC3986() -> String? {
        let unreserved = "-._~/?"
        var allowed = CharacterSet.alphanumerics
        allowed.insert(charactersIn: unreserved)
        return self.addingPercentEncoding(withAllowedCharacters: allowed)
    }

Winchariot

extension String {
  //Validate both that a string is nonempty and that it contains something besides whitespace.
  //  Useful for driving things like enabling a submit button only when a user has entered (meaningful) text
    var isVisuallyEmpty: Bool {
        return self.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
    }
}

Winchariot

//Encoding an enum with associated values is super simple.


enum Answer {
    case rating(Int)
    case freetextResponse(String)
}

extension Answer: Encodable {
    

Winchariot

enum QuestionnaireFeedback {
    case numeric(Int)
    case text(String)
}

extension QuestionnaireFeedback: Encodable {
    enum CodableKeys: String, CodingKey {
        case numeric
        case text
    }

Winchariot

//It is generally nicest to make the variables in your codable types optional, so your decoding can still succeed
//  even if the JSON is missing 1 or more fields

struct MyCodableType: Codable {
  var myVar1: String?
  var myVar2: [Bool]?
  var myVar3: SomeOtherCodableType?
  
  //A CodingKeys enum is required if your variable names don't match the JSON names, case-sensitive.
  //  The cases here should match your clientside variable names, and the associated values should match the JSON