Object-Oriented Programming: Beyond the Basics
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Open the starter playground. You’ll find the system method already implemented. It uses two types from the sources folder for demo purposes: SimulatedFile and SimulatedView. You won’t need to make any changes to those two types. Build and run. It writes our log file.
class System {
var currentFileNameNumber = 5
var activeView = SimulatedView()
func doMainOperation(num1: Int, num2: Int) {
let sum = num1 + num2 // 1
let stringSum = "\(sum)" // 2
let formatter = NumberFormatter() // 3
formatter.locale = Locale(identifier: "ar")
let localizedSum = formatter.string(from: NSNumber(integerLiteral: sum))!
let attributes: [NSAttributedString.Key : Any] = [ // 4
NSAttributedString.Key.foregroundColor: UIColor.blue,
NSAttributedString.Key.font: UIFont.boldSystemFont(ofSize: 16),
NSAttributedString.Key.underlineStyle: NSUnderlineStyle.single.rawValue
]
let styledString = NSAttributedString(string: localizedSum, attributes: attributes)
activeView.labelText = localizedSum // 5
let activeFileName = "logFile\(currentFileNameNumber).log" // 6
var logFileHandler = SimulatedFile(fileName: activeFileName)
logFileHandler.openFile()
if logFileHandler.numberOfLines >= 100 { // 7
currentFileNameNumber += 1
let newActiveFileName = "logFile\(currentFileNameNumber).log"
logFileHandler.closeFile()
logFileHandler = SimulatedFile(fileName: activeFileName)
logFileHandler.openFile()
}
let logEntry = "\(num1) + \(num2) = \(sum). Presented: \(localizedSum)" // 8
logFileHandler.writeData(logEntry) // 9
logFileHandler.closeFile() // 10
}
}
class Calculator {
}
class Calculator {
class func add(num1: Int, num2: Int) -> Int {
num1 + num2
}
}
func doMainOperation(num1: Int, num2: Int) {
let sum = Calculator.add(num1: num1, num2: num2)
...
class StringManager {
class func toLocalizedValue(num: Int) -> String {
let formatter = NumberFormatter()
formatter.locale = Locale(identifier: "ar")
let localizedSum = formatter.string(from: NSNumber(integerLiteral: num))!
print(localizedSum)
return localizedSum
}
}
func doMainOperation(num1: Int, num2: Int) {
let sum = Calculator.add(num1: num1, num2: num2)
let stringSum = "\(sum)"
let localizedSum = StringManager.toLocalizedValue(num: sum) // new code
class ViewPresenter {
class func showValueOnView(value: String, view: SimulatedView) {
let attributes: [NSAttributedString.Key : Any] = [
NSAttributedString.Key.foregroundColor: UIColor.blue,
NSAttributedString.Key.font: UIFont.boldSystemFont(ofSize: 16),
NSAttributedString.Key.underlineStyle: NSUnderlineStyle.single.rawValue
]
let styledString = NSAttributedString(string: value, attributes: attributes)
view.labelText = styledString
}
}
func doMainOperation(num1: Int, num2: Int) {
let sum = Calculator.add(num1: num1, num2: num2)
let stringSum = "\(sum)"
let localizedSum = StringManager.toLocalizedValue(num: sum)
ViewPresenter.showValueOnView(value: localizedSum, view: activeView) // new code
let logEntry = "\(num1) + \(num2) = \(sum). Presented: \(localizedSum)"
...
class LogManager {
public func addLogEntry(_ entry: String) {
}
}
class LogManager {
private static var currentInstance: LogManager?
private init() {
}
class func singleton() -> LogManager {
if currentInstance == nil {
currentInstance = .init()
}
return currentInstance!
}
...
}
class LogManager {
private static var currentInstance: LogManager?
private static let maxLogSize = 100 // new code
private var currentFileNameNumber = 5
private var logFileHandler: SimulatedFile!
private init() {
let activeFileName = fileName(numbered: currentFileNameNumber)
logFileHandler = SimulatedFile(fileName: activeFileName)
logFileHandler.openFile()
}
class func singleton() -> LogManager {
if currentInstance == nil {
currentInstance = .init()
}
return currentInstance!
}
public func addLogEntry(_ entry: String) {
verifyLogSize()
print("\(entry) | Log entry saved.")
}
private func fileName(numbered: Int) -> String { // new code
"logFile\(numbered).log"
}
private func verifyLogSize() { // new code
if logFileHandler.numberOfLines >= LogManager.maxLogSize_const {
currentFileNameNumber += 1
logFileHandler.closeFile()
let newFileName = fileName(numbered: currentFileNameNumber)
logFileHandler = SimulatedFile(fileName: newFileName)
logFileHandler.openFile()
}
}
}
func doMainOperation(num1: Int, num2: Int) {
...
let logEntry = "\(num1) + \(num2) = \(sum). Presented: \(localizedSum)"
LogManager.singleton().addLogEntry(logEntry) // new code