---
title: Captura en Flutter
description: Ejecuta la captura de un flujo Journey en una app Flutter con platform channels, usando el link devuelto por la creación de Human Plugin.
canonical: https://developer.unico.io/es/human-plugin/integrations/flutter
locale: es
generated_by: markdown-export
---

# Captura en Flutter

Abre la captura desde una app Flutter con un platform channel.

Tu backend crea el proceso en Human Plugin con un flujo Journey y un `callbackUri` que usa el esquema de URL de tu app. Un `MethodChannel` abre el `link` de la respuesta en `ASWebAuthenticationSession` en iOS y en Custom Tabs en Android. No se necesita ningún paquete externo.

Conserva el `id` de Human Plugin de la respuesta de la creación. Tu backend lee el resultado con él.

## Requisitos previos

- Flutter 3 o posterior
- Xcode 14 o posterior para iOS
- Android Studio para Android
- Un esquema de URL único para tu app, como `myapp`

## 1. Crea el proceso con tu esquema

Tu backend envía el esquema como `callbackUri`:

```json
{
  "flow": "humantoken",
  "clientId": "client-a",
  "correlationId": "order-1001",
  "credential": { "type": "DUI_TYPE_NG_BVN", "value": "<document number>" },
  "callbackUri": "myapp://callback"
}
```

y devuelve `id` y `link` a la app.

## 2. Crea el servicio en Dart

```dart
// lib/services/capture_service.dart
import 'package:flutter/services.dart';

class CaptureService {
  static const _channel = MethodChannel('capture_plugin');

  /// Devuelve true cuando la captura terminó, false cuando la persona la cerró.
  Future<bool> open(String link) async {
    try {
      final result = await _channel.invokeMethod<String>('openSession', {'url': link});
      return result != null;
    } on PlatformException {
      return false;
    }
  }
}
```

## 3. Implementa el plugin de iOS

```swift
// ios/Runner/CapturePlugin.swift
import Flutter
import AuthenticationServices

class CapturePlugin: NSObject, FlutterPlugin, ASWebAuthenticationPresentationContextProviding {
    private var session: ASWebAuthenticationSession?

    static func register(with registrar: FlutterPluginRegistrar) {
        let channel = FlutterMethodChannel(name: "capture_plugin", binaryMessenger: registrar.messenger())
        let instance = CapturePlugin()
        registrar.addMethodCallDelegate(instance, channel: channel)
    }

    func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
        guard call.method == "openSession",
              let args = call.arguments as? [String: Any],
              let urlString = args["url"] as? String,
              let url = URL(string: urlString) else {
            result(FlutterMethodNotImplemented)
            return
        }

        let newSession = ASWebAuthenticationSession(
            url: url,
            callbackURLScheme: "myapp"
        ) { callbackURL, error in
            self.session = nil
            if let callbackURL = callbackURL {
                result(callbackURL.absoluteString)
            } else {
                result(FlutterError(code: "SESSION_ERROR",
                                    message: error?.localizedDescription ?? "Session cancelled",
                                    details: nil))
            }
        }
        newSession.presentationContextProvider = self
        newSession.prefersEphemeralWebBrowserSession = true
        newSession.start()
        session = newSession
    }

    func presentationAnchor(for session: ASWebAuthenticationSession) -> ASPresentationAnchor {
        guard let windowScene = UIApplication.shared.connectedScenes.first as? UIWindowScene,
              let window = windowScene.windows.first else {
            return ASPresentationAnchor()
        }
        return window
    }
}
```

Regístralo en `AppDelegate.swift`:

```swift
CapturePlugin.register(with: self.registrar(forPlugin: "CapturePlugin")!)
```

## 4. Implementa el plugin de Android

Agrega la dependencia a `android/app/build.gradle`:

```groovy
implementation("androidx.browser:browser:1.5.0")
```

```kotlin
// android/app/src/main/kotlin/<your.package>/CapturePlugin.kt
package com.yourapp

import android.net.Uri
import androidx.browser.customtabs.CustomTabsIntent
import io.flutter.embedding.engine.plugins.FlutterPlugin
import io.flutter.embedding.engine.plugins.activity.ActivityAware
import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding
import io.flutter.plugin.common.MethodCall
import io.flutter.plugin.common.MethodChannel

class CapturePlugin : FlutterPlugin, MethodChannel.MethodCallHandler, ActivityAware {
    private var channel: MethodChannel? = null
    private var binding: ActivityPluginBinding? = null
    private var pendingResult: MethodChannel.Result? = null

    override fun onAttachedToEngine(flutterBinding: FlutterPlugin.FlutterPluginBinding) {
        channel = MethodChannel(flutterBinding.binaryMessenger, "capture_plugin")
        channel?.setMethodCallHandler(this)
    }

    override fun onMethodCall(call: MethodCall, result: MethodChannel.Result) {
        if (call.method == "openSession") {
            val url = call.argument<String>("url") ?: return result.error("MISSING_URL", "URL is required", null)
            pendingResult = result
            val activity = binding?.activity ?: return result.error("NO_ACTIVITY", "No activity", null)
            CustomTabsIntent.Builder().build().launchUrl(activity, Uri.parse(url))
        } else {
            result.notImplemented()
        }
    }

    fun handleRedirect(uri: Uri) {
        if (uri.scheme == "myapp") {
            pendingResult?.success(uri.toString())
            pendingResult = null
        }
    }

    override fun onAttachedToActivity(binding: ActivityPluginBinding) { this.binding = binding }
    override fun onDetachedFromActivity() { binding = null }
    override fun onReattachedToActivityForConfigChanges(binding: ActivityPluginBinding) { this.binding = binding }
    override fun onDetachedFromActivityForConfigChanges() { binding = null }
    override fun onDetachedFromEngine(binding: FlutterPlugin.FlutterPluginBinding) { channel = null }
}
```

Regístralo y gestiona el regreso en `MainActivity.kt`:

```kotlin
override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
    super.configureFlutterEngine(flutterEngine)
    flutterEngine.plugins.add(CapturePlugin())
}

override fun onNewIntent(intent: Intent) {
    super.onNewIntent(intent)
    intent.data?.let { uri ->
        if (uri.scheme == "myapp") {
            val plugin = flutterEngine?.plugins?.get(CapturePlugin::class.java) as? CapturePlugin
            plugin?.handleRedirect(uri)
        }
    }
}
```

## 5. Registra tu esquema

### iOS

En `Info.plist`:

```xml
<key>CFBundleURLTypes</key>
<array>
    <dict>
        <key>CFBundleURLSchemes</key>
        <array>
            <string>myapp</string>
        </array>
    </dict>
</array>
```

### Android

En `AndroidManifest.xml`, dentro de tu `<activity>` principal:

```xml
<intent-filter>
    <action android:name="android.intent.action.VIEW" />
    <category android:name="android.intent.category.DEFAULT" />
    <category android:name="android.intent.category.BROWSABLE" />
    <data android:scheme="myapp" android:host="callback" />
</intent-filter>
```

## 6. Inicia la captura

```dart
final ended = await CaptureService().open(link);

if (ended) {
  // La captura terminó. Pide a tu backend que lea el resultado
  // con GET /v1/processes/{id}, usando el id de Human Plugin.
} else {
  // La persona cerró la sesión.
}
```

## Resumen

| Archivo | Propósito |
|---|---|
| `lib/services/capture_service.dart` | Servicio Dart con `MethodChannel` |
| `ios/Runner/CapturePlugin.swift` | iOS: `ASWebAuthenticationSession` |
| `ios/Runner/AppDelegate.swift` | Registro del plugin |
| `android/.../CapturePlugin.kt` | Android: Custom Tabs |
| `android/.../MainActivity.kt` | Registro del plugin y gestión del regreso |
| `Info.plist` | Esquema de URL de iOS |
| `AndroidManifest.xml` | Intent filter de Android |