Fimber = Timber like logging for Flutter. May extend to different trees (like native channel logging (?) TBD)

example.dart

import 'package:fimber/fimber.dart';

// initialization in main.dart
  Fimber.addTree(DebugTree());


// usage:

Fimber.d("Test debug $value");
Fimber.de(exIo, "Error reading file: $path");

var log = FimberLog("TestTAG");

log.d("Test debug $value");
log.we(exIo, "Error reading file: $path");

/** example output:
11-01 19:21:51.797 4485-4588/com.test.example.mobile I/flutter: D	TestPage.buildInnerItems.<ac>:	 List updated: count = 1 

*/

fimber.dart

library fimber;

/**
 * Main static Fimber logging.
 */
class Fimber {
  static we(Exception ex, String msg) {
    log("W", msg, ex: ex);
  }

  static w(String msg) {
    log("W", msg);
  }

  static de(Exception ex, String msg) {
    log("D", msg, ex: ex);
  }

  static d(String msg) {
    log("D", msg);
  }

  static ie(Exception ex, String msg) {
    log("I", msg, ex: ex);
  }

  static i(String msg) {
    log("I", msg);
  }

  static ee(Exception ex, String msg) {
    log("E", msg, ex: ex);
  }

  static e(String msg) {
    log("E", msg);
  }

  static log(String level, String msg,
      {String tag = null, Exception ex = null}) {
    _trees[level]?.forEach((logger) => logger.log(level, msg, ex: ex));
  }

  static addTree(LogTree tree) {
    tree.getLevels().forEach((level) {
      var logList = _trees[level];
      if (logList == null) {
        logList = List<LogTree>();
        _trees[level] = logList;
      }
      logList.add(tree);
    });
  }

  static Map<String, List<LogTree>> _trees = new Map<String, List<LogTree>>();
}

/**
 * Debug log tree.
 * Tag generation
 */
class DebugTree extends LogTree {
  static List<String> DEFAULT = ["D", "I", "W", "E"];

  @override
  log(String level, String msg, {String tag: null, Exception ex: null}) {
    var logTag = tag ?? getTag();
    if (logTag != null) {
      print("${level}\t${logTag}:\t ${msg} \n${ex?.toString() ?? ''}");
    } else {
      print("${level} ${msg} \n${ex?.toString() ?? ''}");
    }
  }

  @override
  List<String> getLevels() {
    return DEFAULT;
  }
}
/**
 * Interface for LogTree
 */
abstract class LogTree {
  log(String level, String msg, {String tag = null, Exception ex = null});
  List<String> getLevels();
  String getTag() {
    var stackTraceList = StackTrace.current.toString().split('\n');
    return stackTraceList[6].replaceFirst("<anonymous closure>", "<ac>").split(' ')[6]; // need better error handling
  }
}

/**
 * Stand alone logger with custom tag defined.
 */
class FimberLog {
  String tag;

  FimberLog(this.tag);

  we(Exception ex, String msg) {
    _log("W", tag, msg, ex: ex);
  }

  w(String msg) {
    _log("W", tag, msg);
  }

  de(Exception ex, String msg) {
    _log("D", tag, msg, ex: ex);
  }

  d(String msg) {
    _log("D", tag, msg);
  }

  ie(Exception ex, String msg) {
    _log("I", tag, msg, ex: ex);
  }

  i(String msg) {
    _log("I", tag, msg);
  }

  ee(Exception ex, String msg) {
    _log("E", tag, msg, ex: ex);
  }

  e(String msg) {
    _log("E", tag, msg);
  }

  _log(String level, String tag, String msg, {Exception ex = null}) {
    Fimber.log(level, msg, tag: tag, ex: ex);
  }
}