SquidLogger

SquidLogger is a multicast logger written in Swift that send to multiple logs.

NetworkLogger.debug("hello world.")
PaymentLogger.info("hello world.")

Output

📋 debug [Network] 2018-03-24 03:38:02.494 AppDelegate.swift(18) application(_:didFinishLaunchingWithOptions:) - hello world.
💡 info [Payment] 2018-03-24 03:38:02.494 AppDelegate.swift(18) application(_:didFinishLaunchingWithOptions:) - hello world.

Why did I make this?

My project contains multiple logs. (e.g.: Crashlytics logging, Xcode console, our log server)
I don't want to write the same code. Like the next.

let text = "Fail to fetching tha User data."
Crashlytics.log(text)
print(text)
OurLogServer.error(text)

I want to control logging per modules. Like the next.

• log to Networking is warning or more.
• log to Payment is debug or more.

Therefore I needed this logger.

How to use

Mostly simple

Initialize and default logger. Log stream is only default console log stream if SquidLoggerManager.configure() arguments empty when initialize.

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

      // Initialize code
      SquidLoggerManager.configure()

      // Each logs with log level
      IkaLogger.debug("hello world.")
      IkaLogger.info("hello world.")
      IkaLogger.warn("hello world.")
      IkaLogger.error("hello world.")
      IkaLogger.fatal("hello world.")

      return true
    }
}

Output

📋 info [Default] 2018-03-24 03:38:02.494 AppDelegate.swift(18) application(_:didFinishLaunchingWithOptions:) - hello world.
💡 info [Default] 2018-03-24 03:38:02.494 AppDelegate.swift(19) application(_:didFinishLaunchingWithOptions:) - hello world.
⚠️ warn [Default] 2018-03-24 03:38:02.496 AppDelegate.swift(20) application(_:didFinishLaunchingWithOptions:) - hello world.
🚫 error [Default] 2018-03-24 03:38:02.496 AppDelegate.swift(21) application(_:didFinishLaunchingWithOptions:) - hello world.
💔 fatal [Default] 2018-03-24 03:38:02.496 AppDelegate.swift(22) application(_:didFinishLaunchingWithOptions:) - hello world.

Attention This is sample so I don't recommend you. Because this library is a multicast logger and not a logger. So confirm below.

How to use detail

Change a log level

SquidLoggerManager.defaultLogLevel will apply to all log streams.

SquidLoggerManager.configureLogLevel(to: .info)
SquidLoggerManager.defaultLogLevel = .warn

Add new log streams

At first, implement a log stream.

struct ConsoleLogger: SquidLogStreaming {
    public func print<T>(_ object: T) {
        Swift.print(object)
    }
}

Next, add stream to SquidLoggerManager.

SquidLoggerManager.configure(streams: [ConsoleLogger()])

Attention Will remove default log stream from managed log streams if added any new log stream.

Change a log level of a log stream

A log stream(ConsoleLogger) has already been implemented.

SquidLoggerManager.configureLogLevel(to: .error, at: ConsoleLogger.self)

Add new log modules

You just implement below if you want to use for networking area.

struct NetworkLogger: SquidLogger {
    static var category: String = "Network"
    static var logLevel: SquidLogLevel?
}

You will just call a NetworkLogger.

NetworkLogger.info("User data fetch completed")

Attention SquidLogger isn't thread safe. Because this library primary purpose is multicast. logging is not important purpose.

Change a log level of a log module

struct NetworkLogger: SquidLogger {
    static var category: String = "Network"
    static var logLevel: SquidLogLevel? = .debug
}

NetworkLogger.logLevel = .error

Change a symbol of log level

At first, Implement symboler.

struct MyLogLevelSymbol: SquidLogLevelSymbol {
    func toSymbol(from level: SquidLogLevel) -> String {
        switch level {
        case .info:  return "I"
        case .debug: return "D"
        case .warn:  return "W"
        case .error: return "E"
        case .fatal: return "F"
        case .none:  return ""
        }
    }
}

configure your symboler instance.

SquidLoggerManager.logLevelSymboler = MyLogLevelSymbol()

Change a log message format

struct MyTextFormatter: SquidLogTextFormatter {
    func format<T>(_ params: SquidLogParameter<T>) -> String {
        return "\(params.object)"
    }
}

SquidLoggerManager.textFormatter = MyTextFormatter()

Change a log message format of log stream

implement SquidLogStreaming.makeLogText method.

struct ConsoleLogger: SquidLogStreaming {
    func makeLogText<T>(_ params: SquidLogParameter<T>) -> String? {
        return "\(params.level):\(params.object)"
    }
}

Filter a log message of log stream

Implement SquidLogStreaming.filterLogText method.

struct ConsoleLogger: SquidLogStreaming {
  func filterLogText(_ text: String) -> String {
      guard let regex = try? NSRegularExpression(pattern: "hello", options: []) else { return text }
      let range = NSRange(location: 0, length: text.count)
      return regex.stringByReplacingMatches(in: text, options: [], range: range, withTemplate: "<FILTERED>")
  }
}

IkaLogger.warn("hello world.")

📋 warn [Default] 2018-03-24 03:38:02.494 AppDelegate.swift(18) application(_:didFinishLaunchingWithOptions:) - <FILTERED> world.

About filtering of log level

Final Level	SquidLogManager. defaultLogLevel	SquidLogger. logLevel	SquidLogStreaming. logLevel
debug	debug	nil	nil
info	debug	info	nil
warn	debug	nil	warn
warn	debug	info	warn
error	error	nil	nil
info	error	info	nil
warn	error	nil	warn
warn	error	info	warn

Runtime Requirements

• Swift 3.2 or later
• iOS 9 or later
• Xcode 9.2 or later

Library implementation policy

• Don't forget primary purpose.
• Lightweight