Tolbaaken

A pure Kotlin logging library for Android with zero overhead.

Motivation

I created this library because I wanted a pure Kotlin logging library with zero overhead in production apps. This project is inspired by Timber.

Zero overhead

Building a log-message could potentially be a expensive operation, especially if you log objects using the toString method:

Tolbaaken.info { "Log some object: $object" }

With Tolbaaken the log-message is computed inside a lambda which is not executed when logging is disabled. Tolbaakens log methods are inlined, so there is no overhead of creating a anonymous inner class.

Usage

In your application do the following to enable logging for debug builds:

if (BuildConfig.DEBUG) {
  Tolbaaken.logger = AndroidTolbaakenLogger
}

Some logging examples:

Tolbaaken.debug { "This is a debug message" }
Tolbaaken.info(tag = "CustomTag") { "This is a info message" }

try {
  // crash and burn
} catch(e: Exception) {
  Tolbaaken.warn(e) { "Yikes, something went wrong..." }
}

Disable logging:

Tolbaaken.logger = null

Download

You can find Tolbaaken on jitPack: https://jitpack.io/#Q42/Tolbaaken/1.0

Step 1. Add the JitPack repository to your build file

allprojects {
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}

Step 2. Add the dependency

dependencies {
        compile 'com.github.Q42:Tolbaaken:1.0'
}

Custom logging

Sometimes you want custom log handling, for example logging Exceptions to some crash reporting library.

In your application initialize your custom logger

Tolbaaken.logger = CustomCrashReportingLogger

Custom logger implementation

object CustomCrashReportingLogger : TolbaakenLogger {
    override fun log(level: TolbaakenLogLevel, tag: String, message: String, throwable: Throwable?) {
        // Forward logging to the Android logger
        AndroidTolbaakenLogger.log(level, tag, message, throwable)

        if(level == TolbaakenLogLevel.Error && throwable != null) {
            // TODO Log to crash reporting...
        }
    }
}

Android Studio Live templates

To use the Tolbaaken live templates, put the Tolbaaken live template file at the correct live templates location. At the time of writing this location is on MacOS: ~/Library/Application Support/Google/AndroidStudio<version>/templates

Check out the live templates to see what they do. For example, tolme generates code that logs the current method and the params it was called with. In a Fragment's onCreateView, tolme would generate this code:

Tolbaaken.debug { "onCreateView() called with: inflater = [$inflater], container = [$container], savedInstanceState = [$savedInstanceState]" }

Library name

This library's name is inspired by the lighthouse on the island Kotlin which is named "Tolbaaken".