Journal

Journal gives you a new way to think about logging in your application. You can log everything to the Journal Client application, where you can filter your logs to only see the relevant loglines.

It has all the needed logging features, so you can use it as the primary logging library in your application.

Integration

Cocoapods

Update your Podfile similarly:

platform :ios, '10.0'

# You need to set target when you use CocoaPods 1.0.0 or later.
target 'SampleTarget' do
  use_frameworks!
  pod 'Journal'
end

Carthage

Add to your Cartfile:

github "holloandris/Journal"

Usage

Logging

Starting to use Journal is easy. Just add the Loggers and LoggingDetailProviders which you would like to use, and then use the five logging functions to log on the different logging levels:

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    JournalProvider.shared.journal.add(logger: BonjourLogger())
    JournalProvider.shared.journal.add(logger: ConsoleLogger())
    JournalProvider.shared.journal.add(loggingDetailProvider: TimeLoggingDetailProvider())
    JournalProvider.shared.journal.add(loggingDetailProvider: ClassLoggingDetailProvider())
    
    return true
}

Logging from a class only needs the Journal module to be imported, then you can use the macro functions:

import Journal

class ExampleViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        
        error("Failed to load ExampleViewController", .customError)
        warning("Failed to load some resource")
        info("Example screen visible")
        debug("ExampleViewController was loaded")
        verbose("Called viewDidLoad()")
    }
    
}

Logging Context

Logging contexts are basicly global states in the application. Generally you should avoid these, but in logging they can be very useful, especially when tracing back what led to a crash. The easiest example is the identifier of the logged in user. There might be several states in your application which worth to put into the logs.

Logging Detail

States which are changing for every logline are called Logging Details. The most obvious is time. But there are many other details which you could add to your loglines, for example the caller class. The cool thing is you don't have to provide a list for all of your loglines, just need to add them during the initial setup, and you are ready to go.

Journal Client application

Download the Journal Client application: https://github.com/holloandris/JournalClient/releases/download/v0.9.1/JournalClient.app.zip

Open the Journal Client application. It will immediately look for a running application which uses Journal, and after finding it it automatically connects.

To connect to the Journal Client, you have to be on the same network. It uses the same technology for discovery as AirPlay.

How it works

The connection is made via WiFi using Bonjour as a discovery protocol.