[HELP] Example of event listening inside the screen widget about getx HOT 3 CLOSED

import 'dart:async';
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:http/http.dart' as http;

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      navigatorKey: Get.key,
      onGenerateRoute: Router.generateRoute,
      navigatorObservers: [GetObserver(MiddleWare.observer)],
      home: First(),
    );
  }
}

class Router {
  static Route<dynamic> generateRoute(RouteSettings settings) {
    switch (settings.name) {
      case '/':
        return GetRoute(
          page: First(),
          settings: settings,
        );
      case '/second':
        return GetRoute(
            settings: settings, page: Second(), transition: Transition.fade);
      case '/third':
        return GetRoute(
            settings: settings,
            page: Third(),
            transition: Transition.cupertino);
      default:
        return GetRoute(
            settings: settings,
            transition: Transition.fade,
            page: Scaffold(
              body:
                  Center(child: Text('No route defined for ${settings.name}')),
            ));
    }
  }
}

class First extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        leading: IconButton(
          icon: Icon(Icons.add),
          onPressed: () {
            Get.snackbar("hi", "i am a modern snackbar");
          },
        ),
        title: Text('First Route'),
      ),
      body: Center(
        child: RaisedButton(
          child: Text('Open route'),
          onPressed: () {
            Get.toNamed("/second");
          },
        ),
      ),
    );
  }
}

class Second extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        leading: IconButton(
          icon: Icon(Icons.add),
          onPressed: () {
            Get.snackbar("hi", "i am a modern snackbar");
          },
        ),
        title: Text('second Route'),
      ),
      body: Center(
        child: RaisedButton(
          child: Text('Open route'),
          onPressed: () {
            Get.toNamed("/third");
          },
        ),
      ),
    );
  }
}

class Third extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      floatingActionButton: FloatingActionButton(
        onPressed: () => Get.back(),
        child: Icon(Icons.arrow_back),
      ),
      appBar: AppBar(
        title: Text("Third Route"),
      ),
      body: StreamBuilder<List<Job>>(
          stream: JobBloc().jon,
          builder: (context, snapshot) {
            if (snapshot.hasData) {
              List<Job> data = snapshot.data;
              return ListView.builder(
                  itemCount: data.length,
                  itemBuilder: (context, index) {
                    return ListTile(
                      title: Text(data[index].company,
                          style: TextStyle(
                            fontWeight: FontWeight.w500,
                            fontSize: 20,
                          )),
                      subtitle: Text(data[index].description),
                    );
                  });
            } else if (snapshot.hasError) {
              return Text("${snapshot.error}");
            }
            return Center(child: CircularProgressIndicator());
          }),
    );
  }
}

class MiddleWare {
  static observer(Routing routing) {
    if (routing.current == "/third") {
      print(routing.current);
      // Fill your class with data
      JobBloc().fetchData();
    } else if (routing.previous == "/third") {
      JobBloc().dispose();
    }
  }
}

class JobBloc {
  //create private instance
  static JobBloc _instance;
  // create a factory than give always same instance
  factory JobBloc() {
    if (_instance == null) _instance = JobBloc._();
    return _instance;
  }
  JobBloc._();

  //create a Stream
  StreamController<List<Job>> _job = StreamController<List<Job>>.broadcast();

  fetchData() async {
    // fetch data from api
    List<Job> data = await Api.result();
    //add result on stream
    _job.add(data);
  }

  // expose the stream
  get jon => _job.stream;

  dispose() {
    //close the stream
    _job.close();
    //Assign your class to null to reset your instance and have GB clear your class from memory to save resources.
    _instance = null;
  }
}

class Api {
  static Future<List<Job>> result() async {
    //fetch data from internet
    http.Response response =
        await http.get("https://mock-json-service.glitch.me/");
    if (response.statusCode == 200) {
      // Transform the response string into an object
      List jsonResponse = json.decode(response.body);
      //Iterate each object in a list and return it
      return jsonResponse.map((job) => Job.fromJson(job)).toList();
    } else {
      // show one snackbar on error case
      Get.snackbar("Error", "Your API denied this request");
      return [];
    }
  }
}

// create a Model class. I use https://app.quicktype.io/ to autogenerate it
class Job {
  final int id;
  final String position;
  final String company;
  final String description;

  Job({this.id, this.position, this.company, this.description});

  factory Job.fromJson(Map<String, dynamic> json) {
    return Job(
      id: json['id'],
      position: json['position'],
      company: json['company'],
      description: json['description'],
    );
  }
}