Flutter - Pass variable to another screen for URL GET JSON

Question

I'm new to Flutter. On my HOME screen I have a ListView with fetched Json. I want to pass JSON variable ex:id on Tap to the next screen/class 'contantPage' to show another Json loaded from URL with id added. ex.https:/example.com/myjson.php? id=1

Please! Show me the way.

main.dart

onTap: () {
    Navigator.push(context,MaterialPageRoute(
     builder(context)=>ContentPage(
     photo: photos[index]
)),);},

And in my ContentPage.dart should add id value to URL as GET ex:?id=1

Future<Album> fetchAlbum() async {
  // final query1 = Text(photo.publishDate);
  final response = await http
      .get(Uri.parse('https://jsonplaceholder.typicode.com/albums.php?id=I WANT ID HERE'));

  if (response.statusCode == 200) {
    // If the server did return a 200 OK response,
    // then parse the JSON.
    return Album.fromJson(jsonDecode(response.body));
  } else {
    // If the server did not return a 200 OK response,
    // then throw an exception.
    throw Exception('Failed to load album');
  }
}

class Album {
  final int userId;
  final int id;
  final String title;

  Album({
    required this.userId,
    required this.id,
    required this.title,
  });

  factory Album.fromJson(Map<String, dynamic> json) {
    return Album(
      userId: json['userId'],
      id: json['id'],
      title: json['title'],
    );
  }
}

//void main() => runApp(MyApp());

class ContentPage extends StatefulWidget {
//  ContentPage({Key? key, Photo photo}) : super(key: key);
  ContentPage({Key? key, required Photo photo}) : super(key: key);
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<ContentPage> {
  late Future<Album> futureAlbum;

  @override
  void initState() {
    super.initState();
    futureAlbum = fetchAlbum();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Fetch Data Example',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: Scaffold(
        appBar: AppBar(
          title: Text('Fetch Data Example'),
        ),
        body: Center(
          child: FutureBuilder<Album>(
            future: futureAlbum,
            builder: (context, snapshot) {
              if (snapshot.hasData) {
                return Text(snapshot.data!.title);
              } else if (snapshot.hasError) {
                return Text("${snapshot.error}");
              }

              // By default, show a loading spinner.
              return CircularProgressIndicator();
            },
          ),
        ),
      ),
    );
  }
}

Answer 1

Like the photo pass your photosid as follows:

onTap: () {
        Navigator.push(context,MaterialPageRoute(
         builder(context)=>ContentPage(
         photo: photos[index],
    id:photos[index].id,
    )),);},

And then in ContentPage create constructor as follows:

class ContentPage extends StatefulWidget {
Photo photo;
String id;

  ContentPage({Key? key, required this.photo,required this.id,}) : super(key: key);
  @override
  _MyAppState createState() => _MyAppState();
}

In initstate pass your id as follows:

 @override
  void initState() {
    super.initState();
    futureAlbum = fetchAlbum(widget.id);
  }

And finally your fetchAlbum as follows:

Future<Album> fetchAlbum(var id) async {
  // final query1 = Text(photo.publishDate);
  final response = await http
      .get(Uri.parse('https://jsonplaceholder.typicode.com/albums.php?id=id'));



 if (response.statusCode == 200) {
    // If the server did return a 200 OK response,
    // then parse the JSON.
    return Album.fromJson(jsonDecode(response.body));
  } else {
    // If the server did not return a 200 OK response,
    // then throw an exception.
    throw Exception('Failed to load album');
  }
}

Answer 2

I can't understand how to display more than 1 field with my code. I have title field and contentIntro field from Json and want to show all together.

body: Center(
        child: FutureBuilder<Album>(
          future: futureAlbum,
          builder: (context, snapshot) {
            if (snapshot.hasData) {
              return Center(
                child: Text(snapshot.data!.contentIntro),
                //child: Text(snapshot.data!.Title),
              );
            } else if (snapshot.hasError) {
              return Text("${snapshot.error}");
            }

            // By default, show a loading spinner.
            return CircularProgressIndicator();
          },
        ),
      ),