[iOS 응용 개발] 파일을 추상화하는 구조체 만들기(취합)

53380 단어 iOS Swift Xcode tech

안녕하세요.
Zenn에서는 제가 평소에 사용하던 iOS 애플리케이션에서 개발한 Tips 같은 것을 써냈으면 좋겠다고 생각했어요.
지난 8차례 동안 스위프트의 파일 조작을 간단하게 하기 위해 우리는'파일을 추상화하는 구조체'를 만들었다.
나는 지금 보도에 그 원본 코드 전체를 싣고 싶다.
복제해도 작동할 것 같아서요.
이 방법과 속성이 뭐였더라면 과거 기사를 참조하세요.

소스 코드

Xcode:12.4 Swift5

import UIKit

// MARK: ファイルを抽象化した構造体を作る(1)

struct File {
    let path: String
}

extension File {
    
    static let documentDirectoryPath = NSSearchPathForDirectoriesInDomains(
        .documentDirectory,
        .userDomainMask,
        true
    ).first!
    
    static let libraryDirectoryPath = NSSearchPathForDirectoriesInDomains(
        .libraryDirectory,
        .userDomainMask,
        true
    ).first!
    
    static let temporaryDirectoryPath = NSTemporaryDirectory()
    
    static let mainBundlePath = Bundle.main.bundlePath
    
    static let documentDirectory = File(path: documentDirectoryPath)
    static let libraryDirectory = File(path: libraryDirectoryPath)
    static let temporaryDirectory = File(path: temporaryDirectoryPath)
    static let mainBundle = File(path: mainBundlePath)
}

extension File {
    
    func append(pathComponent: String) -> File {
        return File(path: (path as NSString).appendingPathComponent(pathComponent))
    }
    
    static func + (lhs: File, rhs: String) -> File {
        return lhs.append(pathComponent: rhs)
    }
}

extension File: Equatable {
    
    static func == (lhs: File, rhs: File) -> Bool {
        return lhs.path == rhs.path
    }
}

// MARK: ファイルを抽象化した構造体を作る(2)

extension File {
    
    var exists: Bool {
        return FileManager.default.fileExists(atPath: path)
    }
}

extension File {
    
    var parentDirectoryPath: String {
        if path == "/" { return "" }
        return (path as NSString).deletingLastPathComponent
    }
    
    var parentDirectory: File {
        return File(path: parentDirectoryPath)
    }
}

extension File {
    
    func makeDirectory() throws {
        if !exists {
            try FileManager.default.createDirectory(
                atPath: path,
                withIntermediateDirectories: true,
                attributes: nil
            )
        }
    }
}

// MARK: ファイルを抽象化した構造体を作る(3)

extension File {
    
    var url: URL {
        return URL(fileURLWithPath: path)
    }
    
    var data: Data? {
        return try? Data(contentsOf: url)
    }
}

extension File {
    
    func contents(encoding: String.Encoding) -> String? {
        guard let data = self.data else { return nil }
        return String(data: data, encoding: encoding)
    }
    
    var contents: String? {
        return contents(encoding: .utf8)
    }

    func write(contents: String, encoding: String.Encoding = .utf8) throws {
        try parentDirectory.makeDirectory()
        try contents.write(to: url, atomically: false, encoding: encoding)
    }
}

extension File {
    
    var image: UIImage? {
        guard let data = self.data else { return nil }
        return UIImage(data: data)
    }
    
    // JPEGで書き込む
    func write(imageAsJpeg image: UIImage, quality: CGFloat = 0.9) throws {
        guard let data = image.jpegData(compressionQuality: quality) else { return }
        try parentDirectory.makeDirectory()
        try data.write(to: url)
    }
    
    // PNGで書き込む
    func write(imageAsPng image: UIImage) throws {
        guard let data = image.pngData() else { return }
        try parentDirectory.makeDirectory()
        try data.write(to: url)
    }
}

// MARK: ファイルを抽象化した構造体を作る(4)

extension File {
    
    var name: String {
        return (path as NSString).lastPathComponent
    }
    
    var `extension`: String {
        let ext = (name as NSString).pathExtension
        return ext.isEmpty ? "" : ".\(ext)"
    }
    
    var extensionWithoutDot: String {
        let ext = (name as NSString).pathExtension
        return ext.isEmpty ? "" : "\(ext)"
    }
    
    var nameWithoutExtension: String {
        return (name as NSString).deletingPathExtension
    }
}

extension File {
    
    var isFile: Bool {
        var isDirectory: ObjCBool = false
        if FileManager.default.fileExists(atPath: path, isDirectory: &isDirectory) {
            return !isDirectory.boolValue
        }
        return false
    }
    
    var isDirectory: Bool {
        var isDirectory: ObjCBool = false
        if FileManager.default.fileExists(atPath: path, isDirectory: &isDirectory) {
            return isDirectory.boolValue
        }
        return false
    }

// こちらでも可
//  var isDirectory: Bool {
//      return exists && !isFile
//  }
}

// MARK: ファイルを抽象化した構造体を作る(5)

extension File {

    // 作成日時
    var creationDate: Date? {
        return attributes[.creationDate] as? Date
    }
    
    // 更新日時
    var modificationDate: Date? {
        return attributes[.modificationDate] as? Date
    }
    
    // ファイルサイズ
    var size: UInt64 {
        return attributes[.size] as? UInt64 ?? 0
    }
    
    private var attributes: [FileAttributeKey : Any] {
        let attr1 = (try? FileManager.default.attributesOfFileSystem(forPath: path)) ?? [:]
        let attr2 = (try? FileManager.default.attributesOfItem(atPath: path)) ?? [:]
        return [attr1, attr2].reduce(into: [FileAttributeKey : Any](), { ret, attr in
            ret.merge(attr) { $1 }
        })
    }
}

// MARK: ファイルを抽象化した構造体を作る(6)

extension File {

    var files: [File] {
        return filesMap { self + $0 }
    }
    
    var filePaths: [String] {
        return filesMap { (self + $0).path }
    }
    
    var fileNames: [String] {
        return filesMap { $0 }
    }
    
    private func filesMap<T>(_ transform: (String) throws -> (T)) rethrows -> [T] {
        guard let fileNames = try? FileManager.default.contentsOfDirectory(atPath: path) else {
            return []
        }
        return try fileNames.map { try transform($0) }
	// ファイル名で並べたいときは下を使用する
	// return fileNames.sorted().map { try transform($0) }
    }
}

extension File: CustomStringConvertible {
    
    var description: String {
        let type = isDirectory ? "Dir" : "File"
        return "<\(type) \(name)>"
    }
}

// MARK: ファイルを抽象化した構造体を作る(7)

extension File {

    func delete() throws {
        try FileManager.default.removeItem(atPath: path)
    }
    
    func deleteAllChildren() throws {
        try files.forEach { file in
            try file.delete()
        }
    }
    
    func copy(to destination: File, force: Bool = true) throws {
        if force && destination.exists {
            try destination.delete()
        }
        try FileManager.default.copyItem(atPath: path, toPath: destination.path)
    }
    
     func move(to destination: File, force: Bool = true) throws {
        if force && destination.exists {
            try destination.delete()
        }
        try FileManager.default.moveItem(atPath: path, toPath: destination.path)
    }
    
    func rename(to name: String, force: Bool = true) throws -> File {
        let destination = File(path: parentDirectoryPath) + name
        try move(to: destination, force: force)
        return destination
    }
}

// MARK: ファイルを抽象化した構造体を作る(8)

extension File {
    
    func jsonDecoded<T>(_ type: T.Type) throws -> T? where T : Decodable {
        guard let data = self.data else { return nil }
        let decoder = JSONDecoder()
        decoder.keyDecodingStrategy = .convertFromSnakeCase
        return try decoder.decode(type, from: data)
    }
}

extension File {
    
    func jsonEncode<T>(_ value: T) throws -> Data where T : Encodable {
        let encoder = JSONEncoder()
        encoder.outputFormatting = [.prettyPrinted, .sortedKeys]
        encoder.keyEncodingStrategy = .convertToSnakeCase
        return try encoder.encode(value)
    }
    
    func writeEncodedJson<T>(_ value: T, encoding: String.Encoding = .utf8) throws where T : Encodable {
        let encoded = try jsonEncode(value)
        let jsonString = String(data: encoded, encoding: encoding) ?? ""
        try parentDirectory.makeDirectory()
        try jsonString.write(to: url, atomically: false, encoding: encoding)
    }
}