struct_log 0.3.0

Structured logging for Dart with pluggable sinks, OpenTelemetry-compatible context (spanId/traceId), and zero Flutter dependency.

struct_log

Structured logging for Dart with pluggable sinks and OpenTelemetry-compatible context (spanId/traceId). Zero Flutter dependency.

Install

dependencies:
  struct_log: ^0.1.0

Usage

import 'package:struct_log/struct_log.dart';

void main() {
  // Configure sinks.
  final manager = LogManager.instance;
  manager.addSink(StdoutSink(useColors: true));
  manager.addSink(MemorySink());
  manager.minimumLevel = LogLevel.debug;

  // Create a logger.
  final log = manager.getLogger('MyApp');

  // Log messages at various levels.
  log.info('Application started');
  log.debug('Loading config', attributes: {'path': '/etc/app.yaml'});
  log.error('Connection failed', error: 'timeout', spanId: 'abc123');

  // Shut down.
  manager.close();
}

API Overview

Type	Description
LogLevel	Six-level severity enum (trace, debug, info, warning, error, fatal) with OTel-standard names.
LogRecord	Immutable structured log record with spanId, traceId, and Map<String, Object> attributes.
LogSink	Abstract interface with write / flush / close lifecycle.
LogManager	Singleton sink manager with fan-out, level filtering, and fault isolation.
Logger	Named logger facade with convenience methods for each level.
MemorySink	O(1) circular buffer with live onRecord stream. Ideal for debugging UIs and test assertions.
ConsoleSink	Platform-adaptive sink using dart:developer (native) and browser console API (web).
StdoutSink	Platform-adaptive sink using dart:io stdout with optional ANSI colors. No-op on web.

Platform Support

Works on all Dart platforms (native + web) via conditional imports. StdoutSink and ConsoleSink each select the appropriate implementation at compile time.