Merge pull request #3 from Rushabhshroff/develop

Update README.md

Author: Rushabhshroff

README.md

@@ -16,7 +16,7 @@ dependencies:
 
 ```
 
-### Usage (Example With Dio)
+### Basic Usage (Example With Dio)
 
 ```dart
 import 'package:flutter_system_proxy/flutter_system_proxy.dart';
@@ -36,3 +36,41 @@ var proxy = await FlutterSystemProxy.findProxyFromEnvironment(url);
 };
 var response = await dio.get(url);
 ```
+
+### Advanced Usage (Custom Dio Adapter)
+
+```dart
+
+// Create a custom adapter that can help resolve proxy based on urls 
+// (This is important as in some senerio there are PAC files which might have different proxy based on different urls)
+class MyAdapter extends HttpClientAdapter {
+  final DefaultHttpClientAdapter _adapter = DefaultHttpClientAdapter();
+
+  @override
+  Future<ResponseBody> fetch(RequestOptions options,
+      Stream<Uint8List>? requestStream, Future? cancelFuture) async {
+    var uri = options.uri;
+    var proxy =
+        await FlutterSystemProxy.findProxyFromEnvironment(uri.toString()); // This line does the magic
+    _adapter.onHttpClientCreate = (HttpClient clinet) {
+      clinet.findProxy = (uri) {
+        return proxy;
+      };
+    };
+    return _adapter.fetch(options, requestStream, cancelFuture);
+  }
+
+  @override
+  void close({bool force = false}) {
+    _adapter.close(force: force);
+  }
+}
+
+// Use a wrapper around getting dio
+void getDio(){
+  var dio = Dio();
+  dio.httpClientAdapter = MyAdapter();
+  return dio;
+}
+
+```