Quiver Log

Quiver log is a set of logging utilities that make it easy to configure and manage Dart's built in logging capabilities.

Documentation

API Docs are available.

The Basics

Dart's built-in logging utilities are fairly low level. This means each time you start a new project you have to copy/paste a bunch of logging configuration code to setup output locations and logging formats. Quiver-log provides a set of higher-level abstractions to make it easier to get logging setup correctly. Specifically, there are two new concepts: appender and formatter. Appenders define output locations like the console, http or even in-memory data structures that can store logs. Formatters, as the name implies, allow for custom logging formats.

Here is a simple example that sets up a InMemoryAppender with a SimpleStringFormatter:

import 'package:logging/logging.dart';
import 'package:quiver_log/log.dart';

class SimpleStringFormatter implements Formatter {
  String call(LogRecord record) => record.message;
}

main() {
  var logger = Logger('quiver.TestLogger');
  var appender = InMemoryListAppender(SimpleStringFormatter());
  appender.attachLogger(logger);
}

That's all there is to it!

Quiver-log provides three Appenders: PrintAppender which uses Dart's print statement to write to the console, InMemoryListAppender which writes logs to a simple list (this can be useful for debugging or testing) and a WebAppender which will take advantage of web console methods to improve readability in your browser. Additionally, a single Formatter called BasicLogFormatter is included and uses a "MMyy HH:mm:ss.S" format. Of course there is no limit to what kind of appenders you can create.

To create a new kind of Appender simply extend Appender. To create a new Formatter just implement the Formatter abstract class. Take a look at PrintAppender and BasicLogFormatter for an example.

Making Changes and Running Tests

All patches must be formatted using dartfmt and submitted with tests. To run the tests use:

dart run test test/all_tests.dart

dart run test -p chrome test/all_web_tests.dart