How can I access the result of the response of HttpRequest in Dart? - dart

Question

After many attempts to get the content of the response in HttpRequest, I failed completely to know or understand why I can't have what I want, and I must mention that I can log and manipulate the response only inside an onReadyStateChange (onLoad and onLoadEnd are giving me the same results!), but I really want that value outside the callback.
Here is the part of code that I'm stuck with
Map responsData;
req=new HttpRequest()
..open(method,url)
..send(infojson);
req.onReadyStateChange.listen((ProgressEvent e){
if (req.readyState == HttpRequest.DONE ){
if(req.status == 200){
responsData = {'data': req.responseText};
print("data receaved: ${ req.responseText}");
//will log {"data":mydata}
}
if(req.status == 0){
responsData = {'data':'No server'};
print(responsData );
//will log {"data":No server}
}
}
});
//anything here to get responsData won't work

Answer 1

You have to assign an onLoad callback before you call send.
I'm not sure what you mean with only inside an onReadyStateChange.
Maybe you want to assign the responseText to a variable outside the the callback.
Create a method:
Future<String> send(String method, String url, String infojson) {
var completer = new Completer<String>();
// var result;
req=new HttpRequest()
..open(method,url)
..onLoad.listen((event) {
//print('Request complete ${event.target.reponseText}'))
// result = event.target.responseText;
completer.complete(event.target.responseText);
})
..send(infojson);
return completer.future;
}
and call this method like
var result;
send(method, url).then(
(e) {
// result = e;
print('Request complete ${e}'));
});