how-to-build-a-native-cross-platform-project-with-flutter

What this skill does

# How to build a native cross platform project with Flutter


Import dart:html and dart:io in the same project!

> **TLDR** The final source [here](https://github.com/rodydavis/flutter_x/tree/finish).

Up to now you have been able to create projects with Flutter that run on iOS/Android, Web and Desktop but only sharing pure dart plugins.

Flutter launched _Flutter for web_ at Google I/O and was a temporary fork that required you to change imports from `import 'package:flutter/material.dart';` to `import 'package:flutter_web/material.dart';`.

As you can image this was really difficult for a code base as you had to create a fork and change the imports. This also meant that you could not import any package that needed on a path or depended on flutter. The time as come and the merge is complete. Now you no longer need to change the imports!

![](https://rodydavis.com/_/../api/files/pbc_2708086759/5lnog837y4qew5d/n_2_kvxta7kwbn.gif?thumb=)

You can use any plugin now, have a debugger, create new flutter projects with the web folder added, web plugins, and so much more..

## Disclaimer 

You will need to be on the latest flutter for this to work.

[Download Flutter](https://flutter.io/get-started/install/)

![](https://rodydavis.com/_/../api/files/pbc_2708086759/7g4od2ae671i5x5/ff_1_u67ip3pbk5.webp?thumb=)

If you are pretty new to Flutter you can check out [this useful guide](https://flutter.io/get-started/codelab/) on how to create a new project step by step.

![](https://rodydavis.com/_/../api/files/pbc_2708086759/iik1kh354fx05xw/ff_2_9dljl4hgqq.webp?thumb=)

Create a new project named **flutter\_x** and it should look like this:

![](https://rodydavis.com/_/../api/files/pbc_2708086759/0twn40c12rj54an/xx_1_mdevnjnwh7.webp?thumb=)

You can also down the starter project [here](https://github.com/rodydavis/flutter_x/tree/starter).

Your code should look like this:

```
import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.display1,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}
```

Just to make sure everything is working go ahead and run the project on iOS/Android.

![](https://rodydavis.com/_/../api/files/pbc_2708086759/h0481r5t5y941le/xx_2_srn7elmk0c.webp?thumb=)

You should have the counter application running and working correctly. Now quit and run on Chrome. It should be listed as a device. You can also run from the command line flutter run -d chrome.

![](https://rodydavis.com/_/../api/files/pbc_2708086759/98ad6z4ts63y87h/xx_3_iq2vozt6xi.webp?thumb=)

> You do not get hot reload yet on web so be aware of that.

![](https://rodydavis.com/_/../api/files/pbc_2708086759/9uowmg8lvubl0vq/xx_4_f6ht1u443m.webp?thumb=)

Your project should now look like this.

Open your pubspec.yaml and import the following packages.

```
dependencies:
  universal_html:
  url_launcher:
```

> You can also remove the comments generated in the pubspec.yaml

Your pubspec.yaml will now read like this:

```
name: flutter_x
description: A new Flutter project.

version: 1.0.0+1

environment:
  sdk: ">=2.1.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter

cupertino_icons: ^0.1.2
  universal_html: ^1.1.0
  url_launcher: ^5.1.2

dev_dependencies:
  flutter_test:
    sdk: flutter

flutter:

uses-material-design: true
```

By default if you were to check if the device was mobile or web you will get an error at compile time when trying to import a plugin that is not meant for the platform. To get around this we will use dynamic imports.

![](https://rodydavis.com/_/../api/files/pbc_2708086759/49204t2b88i7035/xx_5_a7g3ejp2xp.webp?thumb=)

Create a url\_launcher folder and file url\_launcher.dart, mobile.dart, web.dart, unsupported.dart inside the plugins folder.

In the file url\_launcher.dart add the fo