extensible logger

small, easy to use and extensible logger which prints beautiful logs.
inspired by logger for android.

getting started

just create an instance of logger and start logging:

var logger = logger();

logger.d("logger is working!");

instead of a string message, you can also pass other objects like list, map or set.

output

log console

if you are creating a flutter app, you can use the logger_flutter extension. shake the phone to show an on device console extensible logger .

documentation

log level

you can log with different levels:

logger.v("verbose log");

logger.d("debug log");

logger.i("info log");

logger.w("warning log");

logger.e("error log");

logger.wtf("what a terrible failure log");

to show only specific log levels, you can set:

logger.level = level.warning;

this hides all verbose, debug and info log events.

options

when creating a logger, you can pass some options:

var logger = logger(
  filter: null, // use the default logfilter (-> only log in debug mode)
  printer: prettyprinter(), // use the prettyprinter to format and print log
  output: null, // use the default logoutput (-> send everything to console)
);

if you use the prettyprinter, there are more options:

var logger = logger(
  printer: prettyprinter(
    methodcount: 2, // number of method calls to be displayed
    errormethodcount: 8, // number of method calls if stacktrace is provided
    linelength: 120, // width of the output
    colors: true, // colorful log messages
    printemojis: true, // print an emoji for each log message
    printtime: false // should each log print contain a timestamp
  ),
)

logfilter

the logfilter decides which log events should be shown and which don’t.

the default implementation (debugfilter) shows all logs with level >= logger.level while in debug mode. in release mode all logs are omitted.

you can create your own logfilter like this:

class myfilter extends logfilter {
  @override
  bool shouldlog(logevent event) {
    return true;
  }
}

this will show all logs even in release mode. (not a good idea)

logprinter

the logprinter creates and formats the output, which is then sent to the logoutput.

you can implement your own logprinter. this gives you maximum flexibility.

a very basic printer could look like this:

class myprinter extends logprinter {
  @override
  void log(logevent event) {
    println(event.message);
  }
}

important: every implementation has to send its output using the println() method.

if you created a cool logprinter which might be helpful to others, feel free to open a pull request. 🙂

logoutput

logoutput sends the log lines to the desired destination.

the default implementation (consoleoutput) send every line to the system console.

class consoleoutput extends logoutput {
  @override
  void output(outputevent event) {
    for (var line in event.lines) {
      print(line);
    }
  }
}

possible future logoutputs could send to a file, firebase or to logcat. feel free to open pull requests.

logger_flutter extension

the logger_flutter package is an extension for logger. you can add it to any flutter app. just shake the phone to show the console.

1. add logger_flutter to your pubspec.yaml
2. add the following code into your widget tree

logconsoleonshake(
  child: container() // your widgets
),

more documentation coming soon.