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Rob Napier rnapier

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rnapier / GridView.swift
Last active Sep 27, 2020
GridView that makes me cry
View GridView.swift
// This GridView makes me cry. It is recreating an HTML-style bordered table, sized to
// its data, with a header. It requires a GeometryReader and Preferences, which might
// be unavoidable, but it also requires a *horrible* DispatchQueue.main.async in updateMaxValue.
// This means it doesn't work in Previews, and completely breaks the idea of "declarative" UI.
import SwiftUI
struct WidthPreferenceKey: PreferenceKey {
static var defaultValue: CGFloat = .zero
static func reduce(value: inout CGFloat, nextValue: () -> CGFloat) {
View LengthLimitedTextField.swift
struct LengthLimitedTextField: UIViewRepresentable {
var title: String
@Binding var text: String
var maxLength: Int
var onCommit: () -> Void
init(_ title: String, text: Binding<String>, maxLength: Int = 255, onCommit: @escaping () -> Void) {
self.title = title
self._text = text
self.maxLength = maxLength
View decodeJSON.swift
// Based on
extension Bundle {
// This is synchronous, which is bad if called on the main queue.
func decodeJSON<T: Decodable>(_ type: T.Type = T.self, from filename: String) throws -> T {
guard let path = self.url(forResource: filename, withExtension: nil) else {
throw NSError(domain: NSCocoaErrorDomain,
code: CocoaError.fileNoSuchFile.rawValue,
userInfo: [NSFilePathErrorKey: filename])
View StyledText.swift
// TextStyle.swift
// Created by Rob Napier on 12/20/19.
// Copyright © 2019 Rob Napier. All rights reserved.
import SwiftUI
public struct TextStyle {
rnapier / assertion.swift
Last active Aug 21, 2020
AssertionFailure as a type
View assertion.swift
/// Boring setup. See below for the good parts
public class Logger {
public static let root = Logger(subsystem: .none, parent: nil)
public let subsystem: Subsystem
public let parent: Logger?
public init(subsystem: Subsystem, parent: Logger? = .root) {
self.subsystem = subsystem
View JSONStringConvertible.swift
import Foundation
public protocol JSONStringConvertible: class {
var jsonString: String { get }
extension Logger {
// Converts an arbitrary object into some that is JSON-safe
static func makeJSONObject(_ object: Any) -> Any {
if let jsonObj = object as? JSONStringConvertible {
rnapier / TypeCoder.swift
Last active Jun 13, 2019
Decode based on a type field
View TypeCoder.swift
import Foundation
/// Simple example of decoding different values based on a "type" field
let json = Data("""
"type": "user",
"name": "Alice"
View APIClient.swift
import Foundation
// Provides a nice bare-init for ID types
protocol IDType: Codable, Hashable {
associatedtype Value
var value: Value { get }
init(value: Value)
extension IDType {
View DataStore.swift
import Foundation
protocol DataStorage {
subscript(identifier: String) -> Data? { get set }
extension UserDefaults: DataStorage {
subscript(identifier: String) -> Data? {
get { return data(forKey: identifier) }
set { set(newValue, forKey: identifier) }
View RepositoryStorage.swift
// Fully type-erased solution for
// I don't like type-erasers like this; I believe it can be sliced a better way.
// Compare, which I like, but relies on a common
// currency of serializing everything to Data and working with that instead of having storage that can deals with Element
// directly.
// This example is interesting because, like so many of these toy projects, its design is completely broken and wouldn't
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