How to Implement API Calls in Flutter? - http

Question

I want to create a weather widget app by flutter but i am finding it difficult to do so as there is limited content on flutter. So if anyone knows how to Call , share your knowledge.

Answer 1

If you're building a weather widget you'll almost certainly want a location plugin, which doesn't exist yet but is coming soon.
Here is some code that shows current temperature in San Francisco.
import 'dart:async';
import 'dart:convert';
import 'package:http/http.dart' as http;
import 'package:flutter/material.dart';
void main() {
runApp(new MaterialApp(
home: new MyHomePage(),
));
}
class Weather extends StatelessWidget {
final Map<String, dynamic> data;
Weather(this.data);
Widget build(BuildContext context) {
double temp = data['main']['temp'];
return new Text(
'${temp.toStringAsFixed(1)} °C',
style: Theme.of(context).textTheme.display4,
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePageState createState() => new MyHomePageState();
}
class MyHomePageState extends State<MyHomePage> {
Future<http.Response> _response;
void initState() {
super.initState();
_refresh();
}
void _refresh() {
setState(() {
_response = http.get(
'http://api.openweathermap.org/data/2.5/forecast'
'?q=San+Francisco&units=metric&APPID=14cc828bff4e71286219858975c3e89a'
);
});
}
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text("Weather Example"),
),
floatingActionButton: new FloatingActionButton(
child: new Icon(Icons.refresh),
onPressed: _refresh,
),
body: new Center(
child: new FutureBuilder(
future: _response,
builder: (BuildContext context, AsyncSnapshot<http.Response> response) {
if (!response.hasData)
return new Text('Loading...');
else if (response.data.statusCode != 200) {
return new Text('Could not connect to weather service.');
} else {
Map<String, dynamic> json = JSON.decode(response.data.body);
if (json['cod'] == 200)
return new Weather(json);
else
return new Text('Weather service error: $json.');
}
}
)
),
);
}
}

Answer 2

It could help someone, click here for official doc
1. Making Http Requests; import 'dart:io';
var httpClient = new HttpClient();
Create the client.
Construct the Uri.
Invoke the operation, and await the request object. Optionally,
configure the headers and body of the request.
Close the request, and await the response.
Decode the response
get() async {
var httpClient = new HttpClient();
var uri = new Uri.http(
'example.com', '/path1/path2', {'param1': '42', 'param2': 'foo'});
var request = await httpClient.getUrl(uri);
var response = await request.close();
var responseBody = await response.transform(UTF8.decoder).join();
Map data = JSON.decode(responseBody);
}