fimber 0.1.8

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fimber #

Extensible logging for Flutter.

Package is based on famous Android logging library API - Timber, this is library for simplify logging for Flutter. Using similar (as far as Dart lang allows) method API with same concepts for tree and planting logging tree. Also check out flutter_fimber which extends fimber to platform specific output and logging style.

Getting Started #

To start add using it:

Add fimber to pubspec.yaml

  fimber: ^0.1.8
  • remember about import in file you plan to use Fimber
import 'package:fimber/fimber.dart';

Initialize logging tree on start of your application #

void main() {
  // app code here ...
  // DebugTree options for time elapsed
  // by default DebugTree will output timestamp of the VM/Flutter app
  // to enable elapsed time since planting the tree log
  Fimber.plantTree(DebugTree(printTimeType: DebugTree.TIME_ELAPSED));

Start using it with static methods: #

import 'fimber.dart';

void main() {
  var parameter = 343.0;
  // use directly
  Fimber.i("Test message $argument");
  Fimber.i("Extra error message", ex: Exception("Test thorwable"));
  // other log levels
  try {
    throw Exception("Exception thrown");
  } catch (e, stacktrace) {
    // providing `stacktrace` will better show where issue was thrown
    // if not provided will use log line location.
    Fimber.i("Error caught.", ex: e, stacktrace: stacktrace);

This will log the value and grab a TAG from stacktrace - that is little costly and if more logs will be done per second.

Create tagged version of Fimber #

And use its instance inside class, you can create logger for a dart file or for a class.

var logger = FimberLog("MY_TAG");

void main() {
  logger.d("Test message");

// or inside a class
class SomeBloc {
  var logger = FimberLog("SomeBloc");
  String fetchMessage() {
    logger.d("About to fetch some data.");
    var data = "load something";

    logger.d("Retrived data (len = ${data.length}");
    return data;

Use block function and pass method that uses logger. #

Use this function to log multiple messages with same tag, allows optional return value. Due to nature of auto-tag generation from stacktrace this block only does it once and create local FimberLog instance to pass into the anonymous method.

    var someMessage = "Test message from inside of block";
    var output = Fimber.block((log) {
      log.d("Started block");
      var i = 0;
      for (i = 0; i < 10; i++) {
        log.d("$someMessage, value: $i");
      log.i("End of block");
      return i;

TODO - road map #

  • allow line format configuration from dart code
  • Add Crashlytics plugin (maybe other remote logger tools) with flutter_crashlytics

Licence #

   Copyright 2018 Mateusz Perlak

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   See the License for the specific language governing permissions and
   limitations under the License.

[0.1.8] - Support for stacktrace optional parameter

  • Stacktrace optional parameter after adding ex can be provided from try catch block's second parameter
try {
} catch (ex, stacktrace) {
  Fimber.e("log message", ex:ex, stacktrace: stacktrace);  

[0.1.7] - Changed the ex class

  • Accepting dynamic (any class) on ex property of Logger. This allows to pass Error or Exception or any other value to log statement - toString() is used for printout

[0.1.6] - DebugTree time options

  • Added Elapsed time option for debug tree logging (useful for server side/dart vm logging)
  • Added Time option for debug tree

[0.1.5] - bug fixes

  • Bug fix for log tag auto creation inside constructor.
  • Added tests for factory method logging after constructor log tag fix.

[0.1.4] - iOS exception stacktrace logging

  • no update on fimber, only mirror update for flutter_fimber iOS plugin

[0.1.3] - iOS plugin part for logging

  • Added support for iOS log output.
  • Un-plant tree option.
  • Block function operation.

[0.1.2] - only dart package form fimber

  • Small changes around packaging and removing any flutter references.
  • Revert to print from debugPrint for dart only support.
  • DebugTree got printLog method to override to support other solution to print formatted log line tou output stream, will be helpful in AndroidDebugTree (for example).
  • Updates to stacktrace dumping for DebugTree and added method to extract stacktrace.

[0.1.1] - Small updates

Small updates

[0.1.0] - First Version

Initial version with Fimber debugging and DebugTree


import 'package:fimber/fimber.dart';

void main() {
  // plant a tree - DebugTree()

  Fimber.d("Test message", ex: Exception("test error"));
  var parameter = 100.0;
  Fimber.w("Test message with parameter: $parameter");

  var logger = FimberLog("MY_TAG");
  logger.d("Test message", ex: Exception("test error"));
  logger.w("Test message with parameter: $parameter");

  try {
    throw Exception("Exception thrown");
  } catch (e, stacktrace) {
    // providing stacktrace will better show where issue was thrown
    Fimber.i("Error caught.", ex: e, stacktrace: stacktrace);
  // save auto tag generation on each call in call block.
  Fimber.withTag("TEST BLOCK", (log) {
    log.d("Started block");
    for (var i = 0; i >= 1; i++) {
      log.d("value: $i");
    log.i("End of block");

Use this package as a library

1. Depend on it

Add this to your package's pubspec.yaml file:

  fimber: ^0.1.8

2. Install it

You can install packages from the command line:

with pub:

$ pub get

with Flutter:

$ flutter pub get

Alternatively, your editor might support pub get or flutter pub get. Check the docs for your editor to learn more.

3. Import it

Now in your Dart code, you can use:

import 'package:fimber/fimber.dart';
Version Uploaded Documentation Archive
0.2.0 Mar 31, 2019 Go to the documentation of fimber 0.2.0 Download fimber 0.2.0 archive
0.1.11 Mar 12, 2019 Go to the documentation of fimber 0.1.11 Download fimber 0.1.11 archive
0.1.10 Feb 3, 2019 Go to the documentation of fimber 0.1.10 Download fimber 0.1.10 archive
0.1.9 Jan 22, 2019 Go to the documentation of fimber 0.1.9 Download fimber 0.1.9 archive
0.1.8 Jan 12, 2019 Go to the documentation of fimber 0.1.8 Download fimber 0.1.8 archive
0.1.7 Dec 19, 2018 Go to the documentation of fimber 0.1.7 Download fimber 0.1.7 archive
0.1.6 Dec 18, 2018 Go to the documentation of fimber 0.1.6 Download fimber 0.1.6 archive
0.1.5 Dec 6, 2018 Go to the documentation of fimber 0.1.5 Download fimber 0.1.5 archive
0.1.4 Nov 30, 2018 Go to the documentation of fimber 0.1.4 Download fimber 0.1.4 archive
0.1.3 Nov 27, 2018 Go to the documentation of fimber 0.1.3 Download fimber 0.1.3 archive

All 13 versions...

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We analyzed this package on May 8, 2019, and provided a score, details, and suggestions below. Analysis was completed with status completed using:

  • Dart: 2.3.0
  • pana: 0.12.15


Detected platforms: Flutter, web, other

No platform restriction found in primary library package:fimber/fimber.dart.

Health suggestions

Format lib/fimber.dart.

Run dartfmt to format lib/fimber.dart.


Package Constraint Resolved Available
Direct dependencies
Dart SDK >=2.0.0-dev.68.0 <3.0.0
Dev dependencies
test ^1.5.1