> For the complete documentation index, see [llms.txt](https://docs.wepin.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.wepin.io/en/deprecated/flutter-sdk/init.md).

# Initialization

Here is how to initialize the Wepin widget flutter SDK.

## Initialize 

First, create an instance of the Wepin widget. Then, use the <mark style="color:blue;">`BuildContext`</mark> of the app widget, the App ID and App Key assigned after app registration to initialize the instance.

```dart
import 'package:wepin_flutter/wepin.dart';
import 'package:wepin_flutter/wepin_delegate.dart';
import 'package:wepin_flutter/wepin_inputs.dart';
import 'package:wepin_flutter/wepin_outputs.dart';

final String _appId = "app_id_eg12sf3491azgs520";
final String _appKey = "ak_test_ghq1D5s1sfG234sbnhdsw24mnovk313";
late Wepin _wepin;

@override
void initState() {
  super.initState();
  _wepin = Wepin();
	_handleDeepLink() // Deep Link Handling Function
}

@override
Widget build(BuildContext context) {
  print('SampleApp_build');
  return MaterialApp(
    home: Scaffold(
      appBar: AppBar(
        title: const Text('Wepin Flutter Example'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            ElevatedButton(
                onPressed: () => _initialize(context),
                child: const Text('initialize')),
					],
        ),
      ),
    ),
  );
}


void _initialize(BuildContext context) {
    WidgetAttributes widgetAttributes = WidgetAttributes('ko', 'krw');
    WepinOptions wepinOptions =
        WepinOptions(_appId, _appSdkKey, widgetAttributes);
    _wepin.initialize(context, wepinOptions);
  }
```

### `WepinOptions`

The interface of the <mark style="color:blue;">`WepinOptions`</mark> class, which is used as a parameter for initialization, is as follows.

```dart
public class WepinOptions {
	final String _appId; // App ID
  final String _appKey; // App Key
  final WidgetAttributes _widgetAttributes; // Widget Attributes
}

public class WidgetAttributes {
final String _defaultLanguage;
  final String _defaultCurrency;
}
```

* **`appId`**: *String*\
  App ID assigned during registration
* **`appKey`**: *String*\
  App Key assigned during registration
* **`attributes`**: *Object (optional)*

  Properties of the Wepin Widget

  * **`defaultLanguage`**: *String*\
    The language to be displayed on the widget. The default value is <mark style="color:blue;">`ko`</mark>. The currently supported languages are <mark style="color:blue;">`en`</mark> and <mark style="color:blue;">`ko`</mark>.
  * **`defaultCurrency`:** *String*\
    The currency to be displayed on the widget. The default value is <mark style="color:blue;">`KRW`</mark>. The currently supported currencies are <mark style="color:blue;">`USD`</mark> and <mark style="color:blue;">`KRW`</mark>.<br>

## `isInitialized`

You can use the <mark style="color:blue;">`isInitialized`</mark> method to check if the Wepin instance has been initialized successfully.

The returned value is as follows.

* *boolean*\
  init result; <mark style="color:orange;">`true`</mark> if Wepin SDK is already initialized, otherwise <mark style="color:orange;">`false`</mark>.

```dart
if(_wepin.isInitialized()) {
    // Success to initialize wepin
}
```

## Handle DeepLink / Universal Link

To handle the URL schemes added to the app's Info file or AndroidManifest for use with Wepin, add the following code to the app using Wepin.

```dart
import 'package:uni_links/uni_links.dart';

StreamSubscription? _sub;

// Handle incoming links - the ones that the app will recieve from the OS
// while already started.

  void _handleDeepLink() {
    if (!kIsWeb) {
      // It will handle app links while the app is already started - be it in
      // the foreground or in the background.
      _sub = uriLinkStream.listen((Uri? uri) {
        if (!mounted) return;
        print('got_uri: $uri');
        _wepin.handleWepinLink(uri!);
      }, onError: (Object err) {
        if (!mounted) return;
        print('got_err: $err');
      });
    }
  }
```