Exploring safer localization workflows in SwiftUI ...

SafeLocalizedStringKey.swift

// Copyright © 2020 Flinesoft. All rights reserved.

import Foundation
import SwiftUI

public struct SafeLocalizedStringKey :
    ExpressibleByStringLiteral,
    ExpressibleByStringInterpolation,
    ExpressibleByExtendedGraphemeClusterLiteral,
    ExpressibleByUnicodeScalarLiteral,
    Equatable
{
    static var validationBundle: Bundle = Bundle.main

    let unsafeKey: LocalizedStringKey
    let stringsKey: String

    public init(_ value: String) {
        unsafeKey = LocalizedStringKey(value)
        stringsKey = value

        validateAvailabilityInSupportedLocales()
    }

    public init(stringLiteral value: String) {
        unsafeKey = LocalizedStringKey(stringLiteral: value)
        stringsKey = value

        validateAvailabilityInSupportedLocales()
    }

    public init(stringInterpolation: StringInterpolation) {
        unsafeKey = LocalizedStringKey(stringInterpolation: stringInterpolation.unsafeInterpolation)
        stringsKey = stringInterpolation.interpolatedStringsKey

        validateAvailabilityInSupportedLocales()
    }

    public static func == (lhs: Self, rhs: Self) -> Bool {
        lhs.unsafeKey == rhs.unsafeKey
    }

    private func validateAvailabilityInSupportedLocales() {
        #if DEBUG
        let missingLocales: [String] = Self.validationBundle.localizations.filter { locale in
            let localeBundle = Bundle(path: Self.validationBundle.path(forResource: locale, ofType: "lproj")!)!
            let localizedValue = NSLocalizedString(stringsKey, bundle: localeBundle, comment: "")
            return localizedValue == stringsKey || localizedValue.isEmpty
        }

        guard missingLocales.isEmpty else {
            assertionFailure("Missing locales \(missingLocales) for localized string key '\(stringsKey)'.")
            return
        }
        #endif
    }
}

extension SafeLocalizedStringKey {
    public struct StringInterpolation : StringInterpolationProtocol {
        var unsafeInterpolation: LocalizedStringKey.StringInterpolation
        var interpolatedStringsKey: String

        public init(literalCapacity: Int, interpolationCount: Int) {
            unsafeInterpolation = LocalizedStringKey.StringInterpolation(literalCapacity: literalCapacity, interpolationCount: interpolationCount)
            interpolatedStringsKey = ""
        }

        public mutating func appendLiteral(_ literal: String) {
            unsafeInterpolation.appendLiteral(literal)
            interpolatedStringsKey.append(literal)
        }

        public mutating func appendInterpolation(_ string: String) {
            unsafeInterpolation.appendInterpolation(string)
            interpolatedStringsKey.append("%@")
        }

        public mutating func appendInterpolation<Subject>(_ subject: Subject, formatter: Formatter? = nil) where Subject : ReferenceConvertible {
            unsafeInterpolation.appendInterpolation(subject, formatter: formatter)
            interpolatedStringsKey.append("%@")
        }

        public mutating func appendInterpolation<Subject>(_ subject: Subject, formatter: Formatter? = nil) where Subject : NSObject {
            unsafeInterpolation.appendInterpolation(subject, formatter: formatter)
            interpolatedStringsKey.append("%@")
        }

        public mutating func appendInterpolation<T>(_ value: T) where T : _FormatSpecifiable {
            unsafeInterpolation.appendInterpolation(value)

            switch value {
            case is Int, is Double:
                interpolatedStringsKey.append("%lld")

            default:
                interpolatedStringsKey.append("%@@")
            }
        }

        public mutating func appendInterpolation<T>(_ value: T, specifier: String) where T : _FormatSpecifiable {
            unsafeInterpolation.appendInterpolation(value, specifier: specifier)
            interpolatedStringsKey.append(specifier)
        }

        @available(iOS 14.0, OSX 10.16, tvOS 14.0, watchOS 7.0, *)
        public mutating func appendInterpolation(_ text: Text) {
            unsafeInterpolation.appendInterpolation(text)
            interpolatedStringsKey.append("%@")
        }

        public mutating func appendInterpolation(_ image: Image) {
            unsafeInterpolation.appendInterpolation(image)
            interpolatedStringsKey.append("%@")
        }

        public mutating func appendInterpolation(_ date: Date, style: Text.DateStyle) {
            unsafeInterpolation.appendInterpolation(date, style: style)
            interpolatedStringsKey.append("%@")
        }

        public mutating func appendInterpolation(_ dates: ClosedRange<Date>) {
            unsafeInterpolation.appendInterpolation(dates)
            interpolatedStringsKey.append("%@")
        }

        public mutating func appendInterpolation(_ interval: DateInterval) {
            unsafeInterpolation.appendInterpolation(interval)
            interpolatedStringsKey.append("%@")
        }
    }
}

extension Button where Label == Text {
    public init(safe titleKey: SafeLocalizedStringKey, action: @escaping () -> Void) {
        self.init(titleKey.unsafeKey, action: action)
    }
}

extension ColorPicker where Label == Text {
    public init(safe titleKey: SafeLocalizedStringKey, selection: Binding<Color>, supportsOpacity: Bool = true) {
        self.init(titleKey.unsafeKey, selection: selection, supportsOpacity: supportsOpacity)
    }
}

extension CommandMenu {
    public init(safe nameKey: SafeLocalizedStringKey, @ViewBuilder content: () -> Content) {
        self.init(nameKey.unsafeKey, content: content)
    }
}

extension DatePicker where Label == Text {
    public init(
        safe titleKey: SafeLocalizedStringKey,
        selection: Binding<Date>,
        displayedComponents: DatePicker<Label>.Components = [.hourAndMinute, .date]
    ) {
        self.init(titleKey.unsafeKey, selection: selection, displayedComponents: displayedComponents)
    }

    public init(
        safe titleKey: SafeLocalizedStringKey,
        selection: Binding<Date>,
        in range: ClosedRange<Date>,
        displayedComponents: DatePicker<Label>.Components = [.hourAndMinute, .date]
    ) {
        self.init(titleKey.unsafeKey, selection: selection, in: range, displayedComponents: displayedComponents)
    }

    public init(
        safe titleKey: SafeLocalizedStringKey,
        selection: Binding<Date>,
        in range: PartialRangeFrom<Date>,
        displayedComponents: DatePicker<Label>.Components = [.hourAndMinute, .date]
    ) {
        self.init(titleKey.unsafeKey, selection: selection, in: range, displayedComponents: displayedComponents)
    }

    public init(
        safe titleKey: SafeLocalizedStringKey,
        selection: Binding<Date>,
        in range: PartialRangeThrough<Date>,
        displayedComponents: DatePicker<Label>.Components = [.hourAndMinute, .date]
    ) {
        self.init(titleKey.unsafeKey, selection: selection, in: range, displayedComponents: displayedComponents)
    }
}


extension DisclosureGroup where Label == Text {
    public init(safe titleKey: SafeLocalizedStringKey, @ViewBuilder content: @escaping () -> Content) {
        self.init(titleKey.unsafeKey, content: content)
    }

    public init(safe titleKey: SafeLocalizedStringKey, isExpanded: Binding<Bool>, @ViewBuilder content: @escaping () -> Content) {
        self.init(titleKey.unsafeKey, isExpanded: isExpanded, content: content)
    }
}

extension Label where Title == Text, Icon == Image {
    public init(safe titleKey: SafeLocalizedStringKey, image name: String) {
        self.init(titleKey.unsafeKey, image: name)
    }

    public init(safe titleKey: SafeLocalizedStringKey, systemImage name: String) {
        self.init(titleKey.unsafeKey, systemImage: name)
    }
}

extension Link where Label == Text {
    public init(safe titleKey: SafeLocalizedStringKey, destination: URL) {
        self.init(titleKey.unsafeKey, destination: destination)
    }
}

extension NavigationLink where Label == Text {
    public init(safe titleKey: SafeLocalizedStringKey, destination: Destination) {
        self.init(titleKey.unsafeKey, destination: destination)
    }

    public init(safe titleKey: SafeLocalizedStringKey, destination: Destination, isActive: Binding<Bool>) {
        self.init(titleKey.unsafeKey, destination: destination, isActive: isActive)
    }

    public init<V>(_ titleKey: SafeLocalizedStringKey, destination: Destination, tag: V, selection: Binding<V?>) where V : Hashable {
        self.init(titleKey.unsafeKey, destination: destination, tag: tag, selection: selection)
    }
}

extension Picker where Label == Text {
    public init(safe titleKey: SafeLocalizedStringKey, selection: Binding<SelectionValue>, @ViewBuilder content: () -> Content) {
        self.init(titleKey.unsafeKey, selection: selection, content: content)
    }
}

extension ProgressView where Label == Text {
    public init(safe titleKey: SafeLocalizedStringKey) {
        self.init(titleKey.unsafeKey)

    }

    public init<V>(_ titleKey: SafeLocalizedStringKey, value: V?, total: V = 1.0) where V : BinaryFloatingPoint {
        self.init(titleKey.unsafeKey, value: value, total: total)
    }
}

extension SecureField where Label == Text {
    public init(safe titleKey: SafeLocalizedStringKey, text: Binding<String>, onCommit: @escaping () -> Void = {}) {
        self.init(titleKey.unsafeKey, text: text, onCommit: onCommit)
    }
}

extension Stepper where Label == Text {
    public init(
        safe titleKey: SafeLocalizedStringKey,
        onIncrement: (() -> Void)?,
        onDecrement: (() -> Void)?,
        onEditingChanged: @escaping (Bool) -> Void = { _ in }
    ) {
        self.init(titleKey.unsafeKey, onIncrement: onIncrement, onDecrement: onDecrement, onEditingChanged: onEditingChanged)
    }

    public init<V>(
        safe titleKey: SafeLocalizedStringKey,
        value: Binding<V>,
        step: V.Stride = 1,
        onEditingChanged: @escaping (Bool) -> Void = { _ in }
    ) where V : Strideable {
        self.init(titleKey.unsafeKey, value: value, step: step, onEditingChanged: onEditingChanged)
    }

    public init<V>(
        safe titleKey: SafeLocalizedStringKey,
        value: Binding<V>,
        in bounds: ClosedRange<V>,
        step: V.Stride = 1,
        onEditingChanged: @escaping (Bool) -> Void = { _ in }
    ) where V : Strideable {
        self.init(titleKey.unsafeKey, value: value, in: bounds, step: step, onEditingChanged: onEditingChanged)
    }
}

extension Text {
    public init(safe key: SafeLocalizedStringKey, tableName: String? = nil, bundle: Bundle? = nil, comment: StaticString? = nil) {
        self.init(key.unsafeKey, tableName: tableName, bundle: bundle, comment: comment)
    }
}

extension TextField where Label == Text {
    public init(
        safe titleKey: SafeLocalizedStringKey,
        text: Binding<String>,
        onEditingChanged: @escaping (Bool) -> Void = { _ in },
        onCommit: @escaping () -> Void = {}
    ) {
        self.init(titleKey.unsafeKey, text: text, onEditingChanged: onEditingChanged, onCommit: onCommit)
    }

    public init<T>(
        safe titleKey: SafeLocalizedStringKey,
        value: Binding<T>,
        formatter: Formatter,
        onEditingChanged: @escaping (Bool) -> Void = { _ in },
        onCommit: @escaping () -> Void = {}
    ) {
        self.init(titleKey.unsafeKey, value: value, formatter: formatter, onEditingChanged: onEditingChanged)
    }
}

extension Toggle where Label == Text {
    public init(safe titleKey: SafeLocalizedStringKey, isOn: Binding<Bool>) {
        self.init(titleKey.unsafeKey, isOn: isOn)
    }
}

extension View {
    public func navigationBarTitle(safe titleKey: SafeLocalizedStringKey) -> some View {
        self.navigationBarTitle(titleKey.unsafeKey)
    }

    public func navigationBarTitle(safe titleKey: SafeLocalizedStringKey, displayMode: NavigationBarItem.TitleDisplayMode) -> some View {
        self.navigationBarTitle(titleKey.unsafeKey, displayMode: displayMode)
    }

    public func navigationTitle(safe titleKey: SafeLocalizedStringKey) -> some View {
        self.navigationBarTitle(titleKey.unsafeKey)
    }

    public func help(safe textKey: SafeLocalizedStringKey) -> some View {
        self.help(textKey.unsafeKey)
    }
}

extension WindowGroup {
    public init(safe titleKey: SafeLocalizedStringKey, id: String, @ViewBuilder content: () -> Content) {
        self.init(titleKey.unsafeKey, id: id, content: content)
    }

    public init(safe titleKey: SafeLocalizedStringKey, @ViewBuilder content: () -> Content) {
        self.init(titleKey.unsafeKey, content: content)
    }
}