Split docs into Dart/Flutter and add information about dart:developer

dio/README.md

@@ -484,23 +484,33 @@ For the complete code see [here](../example/lib/queued_interceptor_crsftoken.dar
 
 #### LogInterceptor
 
-You can apply the `LogInterceptor` to log requests and responses automatically in the DEBUG mode:
+You can apply the `LogInterceptor` to log requests and responses automatically.
+
+**Note:** `LogInterceptor` should always be the last interceptor added,
+otherwise modifications by following interceptors will not be logged.
+
+#### Dart
 
 ```dart
 dio.interceptors.add(LogInterceptor(responseBody: false)); // Do not output responses body.
 ```
 
-When using Flutter, you should use `debugPrint` to print logs:
+**Note:** When using the default `logPrint` function, logs will only be printed
+in DEBUG mode (when the assertion is enabled).
+
+
+Alternatively `dart:developer`'s log can also be used to log messages.
+
+#### Flutter
+
+When using Flutter, Flutters own `debugPrint` function should be used.
+This ensures, that debug messages are also available via `flutter logs`.
+
 
 ```dart
 dio.interceptors.add(LogInterceptor(logPrint: (o) => debugPrint(o.toString())));
 ```
 
-**Note:** `LogInterceptor` should be the last interceptor added, otherwise modifications by following interceptors
-will not be logged.
-
-**Note:** Logs will only be printed in the DEBUG mode (when the assertion is enabled).
-
 #### Custom Interceptor
 
 You can customize interceptor by extending the `Interceptor/QueuedInterceptor` class.

dio/lib/src/interceptors/log.dart

@@ -1,3 +1,5 @@
+import 'dart:developer';
+
 import '../dio_exception.dart';
 import '../dio_mixin.dart';
 import '../options.dart';
@@ -10,6 +12,7 @@ import '../response.dart';
 ///
 /// **Note**
 /// When used in Flutter, make sure to use `debugPrint` to print logs.
+/// Alternatively `dart:developer`'s `log` function can also be used.
 ///
 /// ```dart
 /// dio.interceptors.add(LogInterceptor(