README.md

Log4k

This is a simple library for logging in Kotlin. It's inspired by the famous Apache Log4j library.

Usage

After installation, you just need to call a one letter function like the following.

     d("This is my log")

For more advance logging experience you can describe the assumptions of a method with this library as follows.

   fun exampleMethod(foo: Boolean, bar: Boolean, ..., baz: Any?) {
       assumeTrue("Message of AssertionError when this assumption is not satisfied", foo)
           ?.assumeFalse("The same as the above message", bar)
           ...
           ?.assumeNotNull("An other message", baz) {
               // If all the above assumptions get satisfied then this block will be running.
               // Else an Assertion log will be triggered on the proper Appenders.
           }
           // Add more assumptions for the next block
           ?.assumeEquals("A message", foo, bar) {
               // This block will be running if all the above assumptions are true.
           }
   }

In this way, a new developer in your team easily will understand the assumptions of the writer of the method. Also, if each of the assumptions is not satisfied in the runtime, you can log the AssertionError to the Crashlytics or other services for another review of the method in the future.

Installation

Download it in gradle for your Android app like this

implementation "com.log4k:log4k:${log4kVersion}"
implementation "com.log4k:log4k-android:${log4kVersion}"

For the recent version, check out the Bintray badges on top of this README file.

Then in the onCreate method of your Application class setup it like this

if (BuildConfig.DEBUG) {
    Log4k.add(Level.Verbose, ".*", AndroidAppender())
    Log4k.add(Level.Verbose, "com\\.log4k\\.sample\\..+", DefaultAppender())
    Log4k.add(Level.Verbose, ".*", DefaultAppender(writer = PrintWriter(File(externalCacheDir, "debug-log.txt"))))
} else {
    Log4k.add(Level.Assert, "com\\.log4k\\.sample\\..+", DefaultAppender(writer = PrintWriter(File(filesDir, "log.txt"))))
}

As you can see, you can any kind of appender to handle different kinds of logs. For instance, the AndroidAppender appender log as an ordinary Android Log. Or the DefaultAppender(writer = PrintWriter(File(externalCacheDir, "debug-log.txt"))) appender log into a file in external cache directory.

Contribution

Just create your branch from master branch, change it, write additional tests, satisfy all tests, create your pull request, thank you, you're awesome.