crypto_list-FlutterDemo-main-3

main.dart

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

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    //material app widget
    return MaterialApp(
      title: 'Crypto Price List',
      theme: new ThemeData(primaryColor: Colors.white),
      home: CryptoList(),
    ); //use our widget instead of the text previously
  }
}

//creates a stateful widget (data inside will change once created)
class CryptoList extends StatefulWidget {
  @override
  CryptoListState createState() => CryptoListState();
}

class CryptoListState extends State<CryptoList> {
  List _cryptoList;
  //this means that the function will be executed sometime in the future (in this case does not return data)
  Future<void> getCryptoPrices() async {
    //async to use await, which suspends the current function, while it does other stuff and resumes when data ready
    print('getting crypto prices'); //print
    String _apiURL =
        "https://api.coinmarketcap.com/v1/ticker/"; //url to get data
    http.Response response = await http.get(_apiURL); //waits for response
    setState(() {
      this._cryptoList =
          jsonDecode(response.body); //sets the state of our widget
      print(_cryptoList); //prints the list
    });
    return;
  }

  @override
  void initState() { //override creation of state so that we can call our function
    super.initState();
    getCryptoPrices(); //this function is called which then sets the state of our app
  }

//build method
  @override
  Widget build(BuildContext context) {
    //Implements the basic Material Design visual layout structure.
    //This class provides APIs for showing drawers, snack bars, and bottom sheets.
    return Scaffold(
        appBar: AppBar(
          title: Text('CryptoList'),
          actions: <Widget>[
            // will be used to view favourites
            new IconButton(icon: const Icon(Icons.list), onPressed: _pushSaved),
          ],
        ),
        body: new Center(
          // body of the scaffold
          child: new Text('my crypto app'),
        ));
  }

  //will be used later to view favourited cryptos
  void _pushSaved() {}
}