query.dart

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

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  Result result;
  TextEditingController userInput = TextEditingController();
  var displayResult = '';
  var isLoading = false;

  Future<Null> _getResult(String input) async {
    var response = await http.get(
        Uri.encodeFull('http://coupondemoz.tk/sq/' + input),
        headers: {"Accept": "application/json"});
    if (response.statusCode == 200) {
      var jsonData = json.decode(response.body);
      Result r = Result.fromJson(jsonData);
      print(r.result);
      setState(() {
        result = r;
      });
      return null;
    } else {
      throw Exception('Failed to load result');
    }
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
        body: new Column(
      children: <Widget>[
        Padding(
          padding: EdgeInsets.only(top: 40.0),
        ),
        Padding(
          padding: EdgeInsets.all(20.0),
          child: TextField(
              controller: userInput,
              decoration: InputDecoration(
                  labelText: 'Enter URL',
                  hintText: 'Enter URL AS instagram.com/sasd',
                  border: OutlineInputBorder(
                      borderRadius: BorderRadius.circular(5.0)))),
        ),
        new RaisedButton(
            child: new Text('Make Request'),
            onPressed: () {
              _getResult(userInput.text);
            }),
        SizedBox(height: 10.0),
        Text(
          userInput.text.isNotEmpty
              ? "Your Result is ${result.result}"
              : "Please Enter Details to check",
        ),
      ],
    ));
  }
}

class Result {
  String num;
  String result;

  Result({this.num, this.result});

  Result.fromJson(Map<String, dynamic> json) {
    num = json['Num'];
    result = json['result'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['Num'] = this.num;
    data['result'] = this.result;
    return data;
  }
}