How get header token to avoid XMLHttpRequest flutter - json

Question

I'd like to download the JSON file which can be accessed by this url https://firebasestorage.googleapis.com/v0/b/prufungssimulation-caff9.appspot.com/o/5qPfjoZjdNXyN5Ob2q3pFbj5MKy1.json?alt=media. Every time I call the function I get a Error: XMLHttpRequest error. After some researches I found that this error could be avoided by adding my API token in the header. Something like
headers: {
HttpHeaders.authorizationHeader: 'Basic your_api_token_here', //here i want my token
},
But I have no clue how to get my api Token. Does anybody know how to fetch this token? May this error be caused becaus I run it on chrom flutter?
import 'package:http/http.dart' as http;
[...]
[...]
void testFunction(){
var url_string = "https://firebasestorage.googleapis.com/v0/b/prufungssimulation-caff9.appspot.com/o/5qPfjoZjdNXyN5Ob2q3pFbj5MKy1.json?alt=media";
var result = await getJsonFromFirebaseRestAPI(url_string);
print(result);
}
Future<String> getJsonFromFirebaseRestAPI(String url) async {
http.Response response = await http.get(Uri.parse(url));
return response.body;
}
The JSON file result should look like this:
routes: []
It's basically empty I'm just trying to implement the function.
I use http: ^0.13.5
I get the following error:
Error: XMLHttpRequest error.
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/errors.dart 299:10
createErrorWithStack
dart-sdk/lib/_internal/js_dev_runtime/patch/core_patch.dart 341:28
_throw
dart-sdk/lib/core/errors.dart 116:5
throwWithStackTrace
dart-sdk/lib/async/zone.dart 1378:11
callback
dart-sdk/lib/async/schedule_microtask.dart 40:11
_microtaskLoop
dart-sdk/lib/async/schedule_microtask.dart 49:5
_startMicrotaskLoop
dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 166:15
<fn>
Can anybody solve my issue?
Appreciate your time :)

Answer 1

In my case it works perfectly. You just need to add async to testFunction(). You have no need for JWT.
Examples:
void testFunction() async{
var url_string = "https://firebasestorage.googleapis.com/v0/b/prufungssimulation-caff9.appspot.com/o/5qPfjoZjdNXyN5Ob2q3pFbj5MKy1.json?alt=media";
var result = await getJsonFromFirebaseRestAPI(url_string);
print(result);
}
Future<String> getJsonFromFirebaseRestAPI(String url) async {
http.Response response = await http.get(Uri.parse(url));
return response.body;
}
or
try{
final response = await Dio().get( 'https://firebasestorage.googleapis.com/v0/b/prufungssimulation-caff9.appspot.com/o/5qPfjoZjdNXyN5Ob2q3pFbj5MKy1.json?alt=media',
);
print(response.data);
}catch(e){
print(e.toString());
if(e is DioError){
print(e.response!.data);
}
}