Global configuration (interceptor) for dio in Flutter

Question

First time with Flutter. I'm using dio to send HTTP requests, and I have to add a header to all requests, which I do with an interceptor, like this:

Dio dio = new Dio();
dio.interceptors.add(InterceptorsWrapper(
    onRequest:(RequestOptions options) async {
      options.headers["X-Requested-With"] = "XMLHttpRequest";
    })
);

It works in main.dart, but if I want to import another class like MyHomePage.dart and do HTTP requests there, I'd have to redefine the interceptor in that class too.

How can I implement this interceptor for my whole application without adding it in every .dart file?

Answer 1

Create a function that houses the DIO and then call it where needed

Dio getDio() {
  Dio dio = new Dio();
  dio.interceptors.add(InterceptorsWrapper(onRequest: (RequestOptions options) async {
    options.headers["X-Requested-With"] = "XMLHttpRequest";
  }));
  return dio;
}