logd #

A flexible, hierarchical logging library for Dart and Flutter applications. logd provides customizable logging with support for multiple handlers, formatters, sinks, and filters, making it ideal for debugging, monitoring, and production logging in complex projects.

Features #

• Hierarchical Loggers: Dot-separated naming for inheritance (e.g., 'app.ui' inherits from 'app'), with dynamic propagation from parents or global.
• Customizable Output: Boxed, JSON, or custom formatters; console, file, network sinks; level, regex filters.
• Stack Trace Integration: Automatic caller extraction, configurable frame counts per level, ignoring packages like 'flutter'.
• Timestamp Flexibility: Custom patterns with timezone support (e.g., 'yyyy-MM-dd HH:mm:ss ZZZ').
• Multi-line Buffers: Atomic logging for complex messages.
• Flutter Integration: Attach to FlutterError and uncaught exceptions.
• Immutable and Efficient: Loggers are immutable with lazy inheritance for performance.

Installation #

Add logd to your pubspec.yaml:

dependencies:
  logd: ^latest_version

Then run:

dart pub get

For Flutter:

flutter pub get

Usage #

Basic Logging #

Import and get a logger:

import 'package:logd/logd.dart';

final logger = Logger.get('my.app');
logger.info('Application started');

Configuring Loggers #

Set global or specific configs:

Logger.configure('global', logLovel: LogLevel.info);
Logger.configure('my.app', enabled: true, includeFileLineInHeader: true);

Logging with Details #

Include errors and stack traces:

try {
// Code that may fail
} catch (e, stack) {
logger.error('Operation failed', error: e, stackTrace: stack);
}

Multi-line Buffers #

For atomic multi-line logs:

final buf = logger.debugBuffer;
buf?.writeln('Step 1: Initialize');
buf?.writeln('Step 2: Process data');
buf?.sync();

Hierarchical Inheritance #

Child loggers inherit from parents dynamically:

final parent = Logger.get('app');
final child = Logger.get('app.ui');

Logger.configure('app', minimumLevel: LogLevel.warning);
// 'app.ui' now uses warning level unless overridden

Advanced: Freezing Inheritance #

Snapshot configs to children for isolation or optimization:

parent.freezeInheritance();

Attaching to Flutter #

Capture framework errors:

Logger.attachToFlutterErrors();
Logger.attachToUncaughtErrors();

Examples #

Custom Handler #

final handler = Handler(
  formatter: JsonFormatter(),
  sink: FileSink('logs/app.log'),
  filters: [LevelFilter(LogLevel.warning)],
);
Logger.configure('global', handlers: [handler]);

Custom Timestamp #

final ts = Timestamp(formatter: 'yyyy-MM-dd HH:mm:ss Z', timeZone: TimeZone.utc());
Logger.configure('global', timestamp: ts);

For more examples, see the example/ directory.

Contributing #

Contributions are welcome! Please read CONTRIBUTING.md for details.

License #

This project is licensed under the BSD 3-Clause License - see the LICENSE file for details.