Logger

⚠️ Logger is new-as-can-be and lots of stuff is missing. Feel free to contribute.

Logger is a library that gives you a uniform interface for logging and lets you add any number of handlers (which is loggers name for output streams) that catches what you log and does something with it. Built in is the PrintHandler which simply print()s the logs, but it's would be easy to add a Sentry-handler that sends all logs off to Sentry, or an Alert-handler that creates UIAlertControllers for all logs with level .verbose.

Usage tl;dr:

Setting up the built-in PrintHandler to handle all levels and logging some stuff is super easy:

import Logger

Logger.handlers.append(Logger.PrintHandler())

Logger.log(.debug, "log some debugging information")
Logger.log(.warning, "something happened that requires a warning")

Setting up the built-in PrintHandler and creating and setting up a custom handler that only outputs logs with level .verbose as UIAlertControllers is also really easy:

import UIKit
import Logger

public struct AlertHandler: Logger.Handler {
    public let isLevelQualified: (Logger.Level) -> Bool
    
    public init(isLevelQualified: @escaping (Logger.Level) -> Bool) {
        self.isLevelQualified = isLevelQualified
    }
    
    public func log(_ level: Logger.Level, _ message: @autoclosure () -> String, _ args: [String] = [String](), file: StaticString, line: Int, function: StaticString) {
        let title = "Oops, an error occured"
        let alertView = UIAlertController(title: title, message: expandArgs(message(), args), preferredStyle: .alert)
        alertView.addAction(UIAlertAction(title: "Ok", style: .default, handler: nil))
        guard let presenter = UIApplication.shared.keyWindow?.rootViewController?.presentedViewController ?? UIApplication.shared.keyWindow?.rootViewController else {
            Logger.log(.error, "It was not possible to get the currently presented viewcontroller from the keywindows rootviewcontroller, and it was therefore not possible to present an alert for the user with title %1 and message: %2", [title, message()])
            return
        }
        presenter.present(alertView, animated: true, completion: nil)
    }
}

Logger.handlers.append(Logger.PrintHandler())
Logger.handlers.append(AlertHandler { $0 == .verbose })

Logger.log(.debug, "log something that the PrintHandler will output")
Logger.log(.verbose, "log something that both the PrintHandler and the AlertHandler will output")

For more information, see the Documentation.

Version Compatibility

Note that we're aggressive about pushing master forward along with new versions of Swift. Therefore, we highly recommend against pointing at master, and instead using one of the releases we've provided.

Here is the current Swift compatibility breakdown:

Swift Version	Logger Version
3.X	0.1.X

Installation

Swift Package Manager

Add the following line to your dependencies list in your Package.swift:

.Package(url: "https://github.com/ChrisBuchholz/Logger.git",
majorVersion: 0, minor: 1),

Carthage

Add the following to your Cartfile:

github "ChrisBuchholz/Logger"

Then run carthage update.

Follow the current instructions in Carthage's README for up to date installation instructions.

Contributing

See the CONTRIBUTING document. Thank you, contributors!

ChrisBuchholz / Logger