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Flutter Integration

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Intro

The SDK can be integrated into a Flutter project.

How to start the SDK

  • The most important thing is to start the SDK as soon as possible in your app flow. The reason for that is when your app will send an URL request to your server before the SDK was started, the request will not include the SDK's HTTP headers. As a result, HUMAN's Enforcer could block the request and the SDK will not be able to present a challenge to the user. The best place to start the SDK is in the:
    • Application's onCreate function on Android.
    • AppDelegate's didFinishLaunchingWithOptions function on iOS.
  • You should start the SDK on the main thread.
  • Create a HumanManager object that will handle calls from Flutter side.
  • On Android, register the HumanManager in the FlutterEngine.
  • On iOS, setup the channel.

Here is an example of how it should be:

Android

Kotlin / MainApplication.kt:

import android.app.Application

class MainApplication: Application() {

    override fun onCreate() {
        super.onCreate()
        HumanManager.start(this)
    }
}

Kotlin / HumanManager.kt:

import android.app.Application
import com.humansecurity.mobile_sdk.HumanSecurity
import com.humansecurity.mobile_sdk.main.policy.HSPolicy
import com.humansecurity.mobile_sdk.main.policy.HSAutomaticInterceptorType
import com.humansecurity.mobile_sdk.main.HSBotDefenderChallengeResult
import io.flutter.plugin.common.MethodCall
import io.flutter.plugin.common.MethodChannel
import org.json.JSONObject

class HumanManager {

    companion object {
        fun start(application: Application) {
            try {
                val policy = HSPolicy()
                policy.automaticInterceptorPolicy.interceptorType = HSAutomaticInterceptorType.NONE
                HumanSecurity.start(application, "<APP_ID>", policy)
            }
            catch (exception: Exception) {
                println("Exception: ${exception.message}")
            }
        }

        fun handleEvent(call: MethodCall, result: MethodChannel.Result) {
            if (call.method == "humanGetHeaders") {
                val json = JSONObject((HumanSecurity.BD.headersForURLRequest("<APP_ID>") as Map<*, *>?))
                result.success(json.toString())
            }
            else if (call.method == "humanHandleResponse") {
                val handled = HumanSecurity.BD.handleResponse(call.arguments!! as String) { challengeResult: HSBotDefenderChallengeResult ->
                    result.success(if (challengeResult == HSBotDefenderChallengeResult.SOLVED) "solved" else "cancelled")
                    null
                }
                if (!handled) {
                    result.success("false")
                }
            }
            else {
                result.notImplemented()
            }
        }
    }
}

Kotlin / MainActivity.kt:

import androidx.annotation.NonNull
import io.flutter.embedding.android.FlutterActivity
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugin.common.MethodChannel

class MainActivity: FlutterActivity() {

    override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
        super.configureFlutterEngine(flutterEngine)
        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, "com.humansecurity/sdk").setMethodCallHandler {
                call, result ->
            HumanManager.handleEvent(call, result)
        }
    }
}

iOS

Swift / HumanManager.swift:

import Foundation
import Flutter
import HUMAN

class HumanManager {

    static let shared = HumanManager()

    func start() {
        do {
            let policy = HSPolicy()
            policy.automaticInterceptorPolicy.interceptorType = .none

            try HumanSecurity.start(appId: "<APP_ID>", policy: policy)
        }
        catch {
            print("Error: \(error)")
        }
    }

    func setupChannel(with controller: FlutterViewController) {
        let humanChannel = FlutterMethodChannel(name: "com.humansecurity/sdk", binaryMessenger: controller.binaryMessenger)
        humanChannel.setMethodCallHandler({(call: FlutterMethodCall, result: @escaping FlutterResult) -> Void in
            if call.method == "humanGetHeaders" {
                var json: String?
                do {
                    let headers = HumanSecurity.BD.headersForURLRequest(forAppId: "<APP_ID>")
                    let data = try JSONSerialization.data(withJSONObject: headers)
                    json = String(data: data, encoding: .utf8)
                }
                catch {
                    print("Error: \(error)")
                }
                result(json)
            }
            else if call.method == "humanHandleResponse" {
                if let response = call.arguments as? String, let data = response.data(using: .utf8), let httpURLResponse = HTTPURLResponse(url: URL(string: "https://example.com")!, statusCode: 403, httpVersion: nil, headerFields: nil) {
                    let handled = HumanSecurity.BD.handleResponse(response: httpURLResponse, data: data) { challengeResult in
                        result(challengeResult == .solved ? "solved" : "cancelled")
                    }
                    if handled {
                        return
                    }
                }
                result("false")
            }
            else {
                result("")
            }
        })
    }
}

Swift / AppDelegate.swift:

import UIKit
import Flutter

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {

    override func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        GeneratedPluginRegistrant.register(with: self)

        HumanManager.shared.start()

        let controller : FlutterViewController = window?.rootViewController as! FlutterViewController
        HumanManager.shared.setupChannel(with: controller)

        return super.application(application, didFinishLaunchingWithOptions: launchOptions)
    }
}

Let's talk about what we have in the code here:

  1. We start the SDK as soon as possible and on the main thread.
  2. We create a HSPolicy instance. This object is used to configure the SDK's behavior. Here, we set the HSAutomaticInterceptorPolicy/interceptorType property to HSAutomaticInterceptorType/none. This means that the Automatic Interception feature of the SDK is disabled. In short, this feature allows the SDK to manipulate URL requests and handle their responses by itself. However, this feature is not supported in Flutter.
  3. We call the HumanSecurity/start(appId:policy:) function of the SDK. We provide the following parameters:
    • The Application instance (Android only).
    • Your AppID.
    • The policy object that we configured.

Note: If your app communicates with several servers that have different AppID, you can call the HumanSecurity/start(appIds:policy:) function which allow you to pass an array of AppIDs. You should specify the relevant AppID for each API call in the SDK.

How to add HTTP headers and handle block response

In your Dart code, you should do the following:

  1. Crate a MethodChannel.
  2. Add The SDK's HTTP headers to your URL requests.
  3. When a request is blocked, send the block response to the SDK.
  4. Handle the challenge's result.

Here is an example of how it should be:

Dart:

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import '../settings/settings_view.dart';
import 'dart:async';
import 'dart:convert';
import 'package:http/http.dart' as http;

class MyView extends StatelessWidget {

    static const humanPlatform = MethodChannel('com.humansecurity/sdk');

    Future<void> sendUrlRequest() async {
        try {
            final String humanHeaders = await humanPlatform.invokeMethod('humanGetHeaders');
            final Map<String, String> humanHeadersMap = Map.from(json.decode(humanHeaders));
            var url = Uri.https('example.com', '/action');
            var response = await http.get(url, headers: humanHeadersMap);
            if (response.statusCode == 403) {
                final String result = await humanPlatform.invokeMethod('humanHandleResponse', response.body);
                if (result == 'solved') {
                    print("Challenge was solved");
                } else if (result == 'false') {
                    print("Request was not blocked by HUMAN");
                } else if (result == 'cancelled') {
                    print("Challenge was cancelled");
                }
            }
        } on PlatformException catch (exception) {
            print("Exception: '${exception.message}'");
        }
    }
}

Understanding the block response

  1. The HUMAN's Enforcer, when it decides to block a request, returns a JSON string in the response's body. The HTTP status code is 403. Here is an example of the response:

    {
  "vid": "928d7ab3-9cf1-11ee-a624-b802520f369f",
  "uuid": "fd01e6d6-9cf2-11ee-808c-acde48001122",
  "page": "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  "appId": "PXj9y4Q8Em",
  "action": "captcha",
  "collectorUrl": "https://collector-pxj9y4q8em.perimeterx.net"
}

  2. The JSON contains metadata for the SDK.

  3. Your app should pass the whole JSON to the SDK via the HSBotDefender/handleResponse(response:data:callback:) function. Otherwise, the SDK won't present a challenge to the user.

Updated 7 days ago