Examples of Async-Await

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Fri Sep 11 2020 07:50:15 GMT+0000 (UTC)

Saved by @darshjain #dart

//I think your understanding of Promises and async/await is not correct.
//When you make a function async, the await keyword before a promise make sure
//that code execution will pause until the promise fulfilled or rejected. 
//Your code can be simplified:

var currentPromise;

async function asyncFunc(promise){
    // Do some code here
    return await promise;
}

function anotherFunction(){
    asyncFunc(currentPromise);
}
//When we are calling return await promise, the execution engine waits in a
//non-blocking way until the promise fulfilled or rejected, and then it returns 
//the output to the anotherFunction function.

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Asyn-Await

@darshjain

Examples of Async-Await

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How to make height of all widgets inside Row equal the tallest widget

Widget build(BuildContext context) {
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    appBar: AppBar(title: Text('IntrinsicWidth')),
    body: Center(
      child: IntrinsicHeight(
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            RaisedButton(
              onPressed: () {},
              child: Text('Short'),
            ),
            RaisedButton(
              onPressed: () {},
              child: Text('A bit Longer'),
            ),
            RaisedButton(
              onPressed: () {},
              child: Text('The Longest text button'),
            ),
          ],
        ),
      ),
    ),
  );
}

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products.sort((a,b) => a.compareTo(b));

#android #dart #flutter #ios #helloworld

All the code you need to run Hello World in Flutter using a Stateless widget

import 'package:flutter/material.dart';

void main() {
  runApp(
    new MaterialApp(
      title: 'Hello World App',
      home: new myApp(),
    )
  );
}

class myApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('Hello World App'),
      ),
      body: new Center(
        child: new Text(
          'Hello, world!'
        ),
      ),
    );
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Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(title: Text('IntrinsicWidth')),
    body: Center(
      child: IntrinsicWidth(
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            RaisedButton(
              onPressed: () {},
              child: Text('Short'),
            ),
            RaisedButton(
              onPressed: () {},
              child: Text('A bit Longer'),
            ),
            RaisedButton(
              onPressed: () {},
              child: Text('The Longest text button'),
            ),
          ],
        ),
      ),
    ),
  );
}

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Flutter - Container Decoration

Container(
                                child: Text(
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                                  style: TextStyle(
                                      color: Colors.black, fontSize: 30),
                                  textAlign: TextAlign.center,
                                ), //Text
                                height: 40,
                                width: 400,
                                  decoration:
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                  borderRadius: BorderRadius.circular(20),
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                      blurRadius: 5,
                      offset: Offset(0, 3), // changes position of shadow
                    ),
                  ],
                  color: Colors.white,
                  image: DecorationImage(
                    image: AssetImage(filterList[index].itemImg),
                    fit: BoxFit.contain,
                  ),
                ),

Flutter Cheatsheet

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  class MyBlinkingButton extends StatefulWidget {
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    _MyBlinkingButtonState createState() => _MyBlinkingButtonState();
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  class _MyBlinkingButtonState extends State<MyBlinkingButton>
      with SingleTickerProviderStateMixin {
    AnimationController _animationController;

    @override
    void initState() {
      _animationController =
          new AnimationController(vsync: this, duration: Duration(seconds: 1));
      _animationController.repeat(reverse: true);
      super.initState();
    }

    @override
    Widget build(BuildContext context) {
      return FadeTransition(
        opacity: _animationController,
        child: MaterialButton(
          onPressed: () => null,
          child: Text("Text button"),
          color: Colors.green,
        ),
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    @override
    void dispose() {
      _animationController.dispose();
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#dart #flutter #howto

How to decorate text stroke in Flutter

Text("Border test",
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      inherit: true,
      fontSize: 48.0,
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Capitalize the first letter of a String

String capitalize(String s) {
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class HomeView extends GetView<HomeController> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('ListView Filter'),
        centerTitle: true,
      ),
      body: Padding(
        padding: const EdgeInsets.all(10),
        child: Column(
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            const SizedBox(
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            ),
            TextField(
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              decoration: const InputDecoration(
                labelText: 'Search',
                suffixIcon: Icon(Icons.search),
              ),
            ),
            const SizedBox(
              height: 20,
            ),
            Expanded(
              child: Obx(
                () => ListView.builder(
                  itemCount: controller.foundPlayers.value.length, // da nam prikaze duzinu
                  itemBuilder: (context, index) => ListTile( 
                    title: Text(
                      controller.foundPlayers.value[index]['name'], // sta vadimo iz liste
                      style:
                          TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
                    ),
                    subtitle:
                      Text(controller.foundPlayers.value[index]['country']),
                  ),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

final List<Map<String, dynamic>> allPlayers = [
    {"name": "Rohit Sharma", "country": "India"},
    {"name": "Virat Kohli ", "country": "India"},
    {"name": "Glenn Maxwell", "country": "Australia"},
    {"name": "Aaron Finch", "country": "Australia"},
    {"name": "Martin Guptill", "country": "New Zealand"},
    {"name": "Trent Boult", "country": "New Zealand"},
    {"name": "David Miller", "country": "South Africa"},
    {"name": "Kagiso Rabada", "country": "South Africa"},
    {"name": "Chris Gayle", "country": "West Indies"},
    {"name": "Jason Holder", "country": "West Indies"},
  ];
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  @override
  void onInit() {
    super.onInit();
    foundPlayers.value = allPlayers;
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  @override
  void onReady() {
    super.onReady();
  }

  @override
  void onClose() {}
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      results = allPlayers;
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              .toLowerCase()
              .contains(playerName.toLowerCase()))
          .toList();
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Provider koji salje get req na API i tu upisujemo link od API-a

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}

Controller sa kojim pozivamo provider

class HomeController extends GetxController with StateMixin<List<dynamic>> {


  @override
  void onInit() {
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    UserProvider().getUser().then((resp) {
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    }, onError: (err) {

      change(
        null,
        status: RxStatus.error(err.toString()),
      );
    });

  }

}

U view stranici gdje prikazujemo listu

ontroller.obx(
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                            " " +
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                      subtitle: Text(
                        data[index]['email'],
                        style: TextStyle(fontSize: 12),
                      ),
                      trailing: Text(
                        "Age : " + data[index]['dob']['age'].toString(),
                      ),
                    ),
                  ],
                ),
              );
            }),
        onError: (error) => Center(
          child: Text(error),
        ),
      ),
    );

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