Efficient Dio Logger / EffLogger

Dio interceptor: not pretty, but efficient.

For projects using Dio and containing a large number of requests:

• Print large payloads in a copy-friendly format.
• Automatically truncate super long JSON values (image base64, avatar URL...) to avoid console overflow.

适用于使用 Dio 并且包含大量请求的项目:

• 更适合复制和处理大体积请求/响应内容.
• 自动截断超长 JSON value, 避免控制台溢出.

Installation

dart pub add efficient_dio_logger

Usage

Default recommendation: use EffDioLogger.

import 'package:dio/dio.dart';
import 'package:efficient_dio_logger/efficient_dio_logger.dart';

void main() {
  final dio = Dio();

  // Lightweight mode: keep the current compact EffDioLogger output.
  dio.interceptors.add(EffDioLogger());

  dio.interceptors.add(EffDioLogger(
    prettyJson: true,
    compact: false,
    maxWidth: null,
  ));

  // Legacy-compatible mode: matches EfficientDioLogger(...) switches.
  dio.interceptors.add(EffDioLogger.compat(
    request: true,
    response: true,
    requestHeader: false,
    requestBody: false,
    responseHeader: false,
    responseBody: true,
    error: true,
    lineWidth: 160,
    maxWidth: 320,
    compact: true,
    prettyJson: true,
    objectEncoder: (object) {
      if (object is User) {
        return {'id': object.id, 'name': object.name};
      }
      return defaultLogObjectEncoder(object);
    },
    enabled: true,
    logPrint: print,
    filter: (options, args) {
      if (options.path.contains('/posts')) {
        return false;
      }
      if (args.isResponse && args.hasUint8ListData) {
        return false;
      }
      return true;
    },
  ));
}

Modes

• EffDioLogger(): lightweight mode. This keeps the existing REQ/RSP/ERR style and is the default recommendation for new code.
• EffDioLogger.compat(): legacy-compatible mode. Use this when migrating from EfficientDioLogger(...) without changing the old output switches.
• EfficientDioLogger: deprecated, but still source-compatible. Internally it delegates to EffDioLogger.compat(...) so existing code can upgrade without changing constructor arguments.

Common options

• lineWidth configures the divider width used by compat mode.
• response: false completely disables successful response logs without affecting error logs. responseBody: false only hides the response body.
• maxWidth configures the maximum length of a single string before truncation.
• compact enables maxWidth string truncation.
• prettyJson enables indented output for structured data without changing payload types. Top-level strings are always logged as text. Default is false.
• objectEncoder converts custom objects into structured log values. It defaults to defaultLogObjectEncoder.
• logLineBreak customizes line breaks for EffDioLogger output.
• reqExtra, rspExtra, errExtra allow appending custom extra text.

Data fidelity and custom objects

Version 2 preserves JSON-native value types. Numbers, booleans, and null values are no longer converted to strings. Maps and lists remain JSON-encoded, while a top-level request, successful response, or error response string is logged directly as text without JSON outer quotes or escaping. prettyJson formats structured data only and does not parse JSON-looking strings.

Explicit string controls still apply: compact and maxWidth can truncate a top-level string, and logLineBreak replaces its newline characters together with the rest of the emitted log.

Non-string map keys cannot be represented by a JSON object without changing or colliding keys. They are logged as a typed entries list instead. Non-finite doubles, sets, circular references, and non-JSON objects also use an explicit $type marker.

The default object encoder supports FormData, MultipartFile, DateTime, Uri, Duration, BigInt, RegExp, Enum, Type, Error, Exception, StackTrace, and Symbol. Unknown objects fall back to a typed string representation.

To add an application object, return a JSON-compatible value and delegate other objects to the built-in encoder:

final logger = EffDioLogger(
  objectEncoder: (object) {
    if (object is User) {
      return {
        'id': object.id,
        'name': object.name,
        'createdAt': object.createdAt,
      };
    }
    return defaultLogObjectEncoder(object);
  },
);

Values returned by objectEncoder are normalized recursively, so nested custom objects and configured string truncation continue to work.

To place request and response loggers on opposite sides of an interceptor:

final requestLogger = EffDioLogger(
  response: false,
  error: false,
);
final responseLogger = EffDioLogger(request: false);

dio.interceptors.addAll([
  requestLogger,
  encryptionInterceptor,
  responseLogger,
]);

Look Like

Legacy alias

typedef PrettyDioLogger = EfficientDioLogger;