Capture Flutter

Ouvrez la capture depuis une application Flutter avec un platform channel.

Markdown

Votre back-end crée le processus dans Human Plugin avec un flux Journey et un callbackUri qui utilise le scheme d'URL de votre application. Un MethodChannel ouvre le link de la réponse dans ASWebAuthenticationSession sur iOS et dans Custom Tabs sur Android. Aucun package externe n'est nécessaire.

Conservez l'id Human Plugin de la réponse de création. Votre back-end lit le résultat avec cet id.

Prérequis

• Flutter 3 ou version ultérieure
• Xcode 14 ou version ultérieure pour iOS
• Android Studio pour Android
• Un scheme d'URL propre à votre application, tel que myapp

1. Créer le processus avec votre scheme

Votre back-end envoie le scheme comme callbackUri :

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

et renvoie id et link à l'application.

2. Créer le service Dart

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

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

  /// Renvoie true lorsque la capture est terminée, false lorsque la personne l'a fermée.
  Future<bool> open(String link) async {
    try {
      final result = await _channel.invokeMethod<String>('openSession', {'url': link});
      return result != null;
    } on PlatformException {
      return false;
    }
  }
}

3. Implémenter le plugin iOS

// 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
    }
}

Enregistrez-le dans AppDelegate.swift :

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

4. Implémenter le plugin Android

Ajoutez la dépendance à android/app/build.gradle :

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

// 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 }
}

Enregistrez-le et gérez le retour dans MainActivity.kt :

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. Enregistrer votre scheme

iOS

Dans Info.plist :

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

Android

Dans AndroidManifest.xml, à l'intérieur de votre <activity> principale :

<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. Démarrer la capture

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

if (ended) {
  // La capture est terminée. Demandez à votre back-end de lire le résultat
  // avec GET /v1/processes/{id}, en utilisant l'id Human Plugin.
} else {
  // La personne a fermé la session.
}

Récapitulatif

Fichier	Rôle
lib/services/capture_service.dart	Service Dart MethodChannel
ios/Runner/CapturePlugin.swift	iOS : ASWebAuthenticationSession
ios/Runner/AppDelegate.swift	Enregistrement du plugin
android/.../CapturePlugin.kt	Android : Custom Tabs
android/.../MainActivity.kt	Enregistrement du plugin et gestion du retour
Info.plist	Scheme d'URL iOS
AndroidManifest.xml	Intent filter Android