LogKeeper

A simple, plug-and-play file logger for Dart with automatic timestamping and session management.

Features

  • ✨ Zero Configuration - Works out of the box, no setup required
  • 📁 Automatic File Management - Creates timestamped log files for each session
  • ⏰ Built-in Timestamps - Every log entry includes automatic timestamping
  • 🎯 Simple API - Clean, intuitive methods for different log levels
  • 💾 Persistent Logging - All logs are saved to disk automatically

Getting Started

Installation

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

dependencies:
  logkeeper: ^1.3.0

Then run:

flutter pub get

Basic Usage (No Configuration Needed!)

import 'package:logkeeper/logkeeper.dart';

void main() async {
  // Just start logging - no setup required!
  LogKeeper.info('Application started');
  LogKeeper.warning('Low memory detected');
  LogKeeper.error('Connection failed');
  LogKeeper.critical('System failure');

  // Save logs before exiting
  await LogKeeper.saveLogs();
}

That's it! LogKeeper will automatically create a logs/ directory and save all your logs.

Custom Configuration (Optional)

If you need to customize LogKeeper's behavior, call configure() before any logging operations (as the first line in main()):

import 'package:intl/intl.dart';
import 'package:logkeeper/logkeeper.dart';
import 'package:logkeeper/log_level.dart';

void main() async {
  // Optional: customize if needed (call FIRST if you use it)
  LogKeeper.configure(
    logDirectory: 'custom_logs',
    minLevelForProduction: LogLevel.warning,
    fileNameDateFormat: DateFormat('yyyy_MM_dd-HH_mm'),
    timestampFormat: DateFormat('HH:mm:ss.SSS'),
    maxLogAgeDays: 7,
    writeToFileInDevMode: true,
    colorizeConsoleOutput: false,
  );

  // Now log as usual
  LogKeeper.info('Application started with custom config');
  
  await LogKeeper.saveLogs();
}

Configuration Options

All parameters are optional - defaults work great for most cases:

Parameter Type Default Description
logDirectory String? null Directory where log files are saved
minLevelForProduction LogLevel LogLevel.info Minimum level to log in production
maxLogAgeDays int? null Auto-delete logs older than N days
fileNameDateFormat DateFormat yyyy-MM-dd_HH-mm-ss Format for log file names
timestampFormat DateFormat HH:mm:ss Format for timestamps in entries
writeToFileInDevMode bool false Write to file in development mode
colorizeConsoleOutput bool true Colorize the logs displayed by the console

Log Levels

LogKeeper supports four log levels:

Method Use Case Example
info() General information LogKeeper.info('User logged in')
warning() Potentially harmful situations LogKeeper.warning('Disk space low')
error() Error events LogKeeper.error('Network timeout')
critical() Severe errors LogKeeper.critical('Database corrupted')

Log File Format

Log files are created in the log directory (default: logs/) with timestamps:

logs/
└── 2025-10-18_14-30-45.log

Each log entry includes automatic timestamps:

[14:30:45] INFO: Application started
[14:30:46] WARNING: Low memory detected
[14:30:47] ERROR: Connection failed

Best Practices

Always Save Logs

Call saveLogs() before your application exits to ensure all logs are written to disk:

void main() async {
  LogKeeper.info('App started');
  // ... your code ...
  await LogKeeper.saveLogs();  // Don't forget!
}

If You Use configure(), Call It First

Configuration is optional, but if you do use it, call it before logging:

void main() async {
  LogKeeper.configure(/* settings */);  // If used, must be first
  LogKeeper.info('App started');        // Then log normally
  await LogKeeper.saveLogs();
}

Use Appropriate Log Levels

Choose the right log level for each situation:

  • INFO: Normal operations, state changes, milestones
  • WARNING: Unusual situations that don't prevent functionality
  • ERROR: Errors that affect functionality but allow recovery
  • CRITICAL: Severe errors requiring immediate attention

Be Descriptive

Write clear, actionable log messages:

// ❌ Bad
LogKeeper.error('Error');

// ✅ Good
LogKeeper.error('Failed to connect to database: connection timeout after 30s');

FAQ

Do I need to configure LogKeeper?

No! LogKeeper works perfectly without any configuration. The defaults are sensible and work for most applications. Only use configure() if you need custom behavior.

If I do configure, when should I call it?

If you choose to use configure(), call it as the first line in main(), before any logging operations.

Where are log files stored?

By default, log files are stored in a logs/ directory relative to your application's working directory. You can customize this with the logDirectory parameter.

What happens if I don't call saveLogs()?

Some log entries may not be written to disk as they remain in the buffer. Always call saveLogs() before exiting.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Support

If you encounter any issues or have questions, please open an issue on GitHub.

Changelog

See CHANGELOG.md for a list of changes in each version.

Libraries

log_level
logkeeper