Get request is not done with Flutter - http

Question

I'm doing an Flutter application, but I found a problem when I wanted to make some http request. The problem is that when I want to make it, I define the function as asynchronous, and I write await before calling the function http.get(), but the function it´s not executed and the code after the function is not executed also.
The code is below and no error is thrown.
class db{
void get_basic() async{
String url = 'http://example.org/';
Response response = await get(url);
int statusCode = response.statusCode;
print("Listo");
print(statusCode);
}
}
Widget build(BuildContext context){
print("inicio database");
db database = db();
database.get_basic();
print("final database");
main_content main = main_content();
return Scaffold(
appBar: AppBar(
title: Text('Title),
),
body: main,
bottomNavigationBar: bottomNavBar(0,main.refresh),
);
}

Answer 1

async functions always return a future.
A Future object represents a computation whose return value might not yet be available. The Future returns the value of the computation when it completes at some time in the future. Futures are often used for potentially lengthy computations such as I/O and interaction with users.
async functions return futures, that means that they are performed in the future.
because dart uses a single thread to run code that means when it hits await instead of blocking the thread it will move to after the function call and starts exciting code again until it idles.
when the thread has done all of the synchronous code it will go back to await
line and start exciting there.
The get_basic() code should be called after the build is complete.
if you want to rebuild your widget after get_basic() is completed you need to use a FutureBuilder:
class _MyHomePageState extends State<MyHomePage> {
db database;
#override
void initState() {
super.initState();
database = db();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Title'),
),
body: FutureBuilder(
future: database.get_basic(),
builder: (context,snapshot){
if(snapshot.connectionState!=ConnectionState.done){
return Center(
child: Text('Loading...'),
);
} else {
if(snapshot.hasError){
return Center(
child: Text(snapshot.error.toString()),
);
}
return ListView.builder(
itemCount: snapshot.data.length,
itemBuilder: (context, index){
return ListTile(title: Text(snapshot.data[index]['title']),);
},
);
}
},
),
);
}
}
class db{
Future get_basic() async{
try {
String url = 'https://jsonplaceholder.typicode.com/posts';
Response response = await get(url);
return jsonDecode(response.body);
} catch (e) {
print(e);
return [{}];
}
}
}