BasicLogger is a fast, extensible, simple and lightweight logging tool for Dart and Flutter..
It is distributed as a single file module and has no dependencies other than the Dart Standard Library.
Broadcast a single log event to multiple outputs simultaneously. This pattern implements a one-to-many distribution, allowing you to decouple log generation from log persistence. Common for concurrent real-time terminal monitoring and local file archiving.
Logger.root.level = Level.ALL;
final basicLogger = BasicLogger('main');
// attach developer log
basicLogger.attachLogger(DevOutputLogger(basicLogger.name));
// attach output log,
// selfname, default console
// selfonly, if true filter by selfname, else parentName match are output.
final consoleLogger = basicLogger.attachLogger(OutputLogger(
basicLogger.name,
// selfname: 'console',
// selfonly: true,
));
// output to all attach instance
basicLogger.info('hello world');
// output buffer to all attach instance, not include detach instance
basicLogger.output();
// output
// 2024-10-15 02:52:11.405809 [INFO] main: hello worldIsolate logs by functional domains or business categories.
By registering independent loggers for different modules (e.g., Auth, Database, Network), you achieve Separation of Concerns (SoC). This allows for granular control over filtering levels and storage policies for each specific scope.
Logger.root.level = Level.ALL;
final basicLogger = BasicLogger('main');
// attach output log, alias stdout, filter by selfname
final stdoutOutputLogger =
OutputLogger(basicLogger.name, selfname: 'stdout', selfonly: true);
final stdoutLogger = basicLogger.attachLogger(stdoutOutputLogger);
// attach output log, alias stderr, filter by selfname
final stderrOutputLogger =
OutputLogger(basicLogger.name, selfname: 'stderr', selfonly: true);
final stderrLogger = basicLogger.attachLogger(stderrOutputLogger);
stdoutLogger.info('info a11');
stderrLogger.info('error 1234');
stdoutLogger.info('info a22');
// output
// 2026-01-16 10:41:18.957774 [INFO] main.stdout: info a11
// 2026-01-16 10:41:18.967899 [INFO] main.stderr: error 1234
// 2026-01-16 10:41:18.967971 [INFO] main.stdout: info a22- FileOutputLogger, file-based logging for Android, iOS, Linux, macOS, and Windows platforms.
dart pub add basic_logger_file- FileOutputLogger, specify output file path
basicLogger.attachLogger(FileOutputLogger(
basicLogger.name,
dir: './logs/',
));- FileOutputLogger, specify output buffer size
// buffering allows you to write files multiple times instead of writing files once
basicLogger.attachLogger(FileOutputLogger(
basicLogger.name,
bufferSize: 100,
));
// output and clear buffer
basicLogger.output();- FileOutputLogger, specify output categorization
// allow custom log extensions via `ext` parameter for log categorization.
basicLogger.attachLogger(FileOutputLogger(
basicLogger.name,
ext: '_sql.log',
));