Migration Guide: Blitzllama to Wingify User Feedback Flutter SDK

This guide provides step-by-step instructions for migrating your Flutter application from Blitzllama's Survey SDK to Wingify User Feedback Survey SDK.

Overview

Wingify User Feedback SDK provides the same core functionality as Blitzllama with some key architectural differences. The most significant change is that SDK initialization now happens in native code (Android/iOS) rather than in Dart.

Key Differences at a Glance

Step 1: Update Dependencies

Remove Blitzllama

In your pubspec.yaml, remove the Blitzllama dependency:

dependencies:
  blitzllama_flutter: ^0.6.3

Add Wingify User Feedback SDK

Add the Wingify User Feedback Flutter SDK:

dependencies:
  vwo_insights_flutter_sdk: ^2.7.0

Run the following command to update dependencies:

flutter pub get

Step 2: Update Imports

Replace Blitzllama imports with Wingify imports in your Dart files.

Before (Blitzllama):

import 'package:blitzllama_flutter/blitzllama_flutter.dart';

After (Wingify User Feedback):

import 'package:vwo_insights_flutter_sdk/vwo_insights_flutter_sdk.dart';

Step 3: Update Initialization

This is the most significant change. Wingify SDK requires native initialization instead of Dart initialization.

Key Points:

• User ID can be passed during native initialization (optional)
• Use setUserId() later to switch users or identify users after they log in
• For anonymous users, you can pass an empty string or null during initialization, or use a random string with setUserId()

Remove Blitzllama Dart Initialization

Remove the following from your Dart code:

// Remove this
BlitzllamaFlutter.init("<api_key>");

Add Wingify Native Initialization

Android

1. Create an Application class (e.g., FlutterVwoApp.kt) in your Android project:

package com.your.package.name

import android.util.Log
import com.vwo.insights.VWOInsights
import com.vwo.insights.exposed.IVwoInitCallback
import com.vwo.insights.exposed.models.ClientConfiguration
import io.flutter.app.FlutterApplication

class FlutterVwoApp : FlutterApplication() {
    override fun onCreate() {
        super.onCreate()

        // User ID is optional - use "" for anonymous users
        val configuration = ClientConfiguration(
            "YOUR_ACCOUNT_ID",
            "YOUR_SDK_KEY",
            ""  // User ID (optional) - use "" for anonymous, or "user_id" if known
        )
        
        VWOInsights.init(this, object : IVwoInitCallback {
            override fun vwoInitSuccess(s: String) {
                Log.d("VWO", "VWO initialized successfully")
                // Safe to trigger surveys now
                
                // If user logs in later in Flutter, use setUserId():
                // VwoFlutter.setUserId("user_id");
            }

            override fun vwoInitFailed(s: String) {
                Log.e("VWO", "VWO initialization failed: $s")
            }
        }, configuration)
    }
}

2. Register your Application class in AndroidManifest.xml:

<application
    android:name=".FlutterVwoApp"
    ... >
</application>

iOS

Update your AppDelegate.swift:

import UIKit
import Flutter
import vwo_insights_ios_flutter_sdk

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
    override func application(
        _ application: UIApplication,
        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
    ) -> Bool {
        
        // User ID is optional - use nil for anonymous users
        VWO.configure(
            accountId: "YOUR_ACCOUNT_ID",
            sdkKey: "YOUR_SDK_KEY",
            userId: nil  // User ID (optional) - use nil for anonymous, or "user_id" if known
        ) { result in
            switch result {
            case .success(_):
                print("VWO launch Success")
                // If user logs in later in Flutter, use setUserId():
                // VwoFlutter.setUserId("user_id");
            case .failure(_):
                print("VWO launch Failure")
            }
        }
        
        GeneratedPluginRegistrant.register(with: self)
        return super.application(application, didFinishLaunchingWithOptions: launchOptions)
    }
}

Configuration Parameters

Step 4: Update User Management

User Creation

Blitzllama's createUser() is no longer needed. The user ID can be passed during native initialization (optional), or set later using setUserId().

Before (Blitzllama):

BlitzllamaFlutter.createUser(user_id);

After (Wingify User Feedback):

User ID is passed in native initialization (optional), or use setUserId() in Dart:

// When user logs in
final success = await VwoFlutter.setUserId('user_123');
if (success) {
  print('User identified successfully');
}

User Attributes

The method for setting user attributes has changed from individual calls to a single map-based approach.

Before (Blitzllama):

BlitzllamaFlutter.setUserAttribute("plan", "premium", "string");
BlitzllamaFlutter.setUserAttribute("age", "25", "number");
BlitzllamaFlutter.setUserAttribute("is_active", "true", "boolean");

After (Wingify User Feedback):

VwoFlutter.setAttribute({
    "plan": "premium",
    "age": 25,
    "is_active": true
});

User Email and User Name

Use setAttribute to set user email and user name instead of dedicated methods.

Before (Blitzllama):

BlitzllamaFlutter.setUserEmail(email);
BlitzllamaFlutter.setUserName(username);

After (Wingify User Feedback):

VwoFlutter.setAttribute({
    "user_email": "[email protected]",
    "user_name": "John Doe"
});

Survey Language

Before (Blitzllama):

BlitzllamaFlutter.setSurveyLanguage("en");

After (Wingify User Feedback):

VwoFlutter.setSurveyLanguage("en");

Step 5: Update Event Triggers

The method name for triggering surveys has changed from triggerEvent to trackEvent.

Basic Trigger

Before (Blitzllama):

BlitzllamaFlutter.triggerEvent("purchase_completed");

After (Wingify User Feedback):

VwoFlutter.trackEvent("purchase_completed");

Trigger with Event Properties

Before (Blitzllama):

BlitzllamaFlutter.triggerEvent("HomeActivity", {
    "age": 10,
    "name": "John"
});

After (Wingify User Feedback):

VwoFlutter.trackEvent("HomeActivity", {
    "age": 10,
    "name": "John"
});

Step 6: Handle Removed Features

Custom Fonts

The setCustomFont() method is not available in Wingify SDK.

Before (Blitzllama):

BlitzllamaFlutter.setCustomFont("Roboto-Regular", "Roboto-Bold");

After (Wingify User Feedback):

Not available - remove this call.

User Switching

Wingify User Feedback does not have a logout() method. Instead, use setUserId() to switch between users. To create anonymous sessions (equivalent to logout), pass a random string as the user ID.

Before (Blitzllama):

BlitzllamaFlutter.logout();

After (Wingify User Feedback):

Switching to a New User

// When user logs in or switches account
final success = await VwoFlutter.setUserId('new_user_id');
if (success) {
  print('User switch complete');
  // Recording resumes automatically if it was active before
}

Switching to Anonymous User (Logout)

import 'dart:math';

// When user logs out - generate random ID for anonymous tracking
final randomUserId = 'anon_${Random().nextInt(999999)}';
final success = await VwoFlutter.setUserId(randomUserId);
if (success) {
  print('Now tracking as anonymous user');
}

API Reference Mapping

Migration Checklist

• Update pubspec.yaml to use vwo_insights_flutter_sdk ^2.7.0
• Run flutter pub get
• Update all import statements
• Remove Dart-based init() calls
• Add native initialization for Android (FlutterVwoApp.kt)
• Register Application class in AndroidManifest.xml
• Add native initialization for iOS (AppDelegate.swift)
• Replace createUser() with setUserId() for user identification
• Replace BlitzllamaFlutter with VwoFlutter
• Replace triggerEvent() with trackEvent()
• Update setUserAttribute() to use setAttribute() with a map
• Replace setUserEmail() and setUserName() with setAttribute()
• Remove setCustomFont() calls if present
• Replace logout() with setUserId() for user switching
• Test survey triggering in the app

Troubleshooting

Survey not showing after migration?

1. Verify Account ID and SDK Key are correct in native initialization
2. Ensure the Application class is registered in AndroidManifest.xml
3. Check that event names match those configured in the Wingify dashboard
4. Verify the SDK initialization completes successfully before triggering events

Build errors on iOS?

Ensure you have imported the Wingify SDK in your AppDelegate.swift:

import vwo_insights_ios_flutter_sdk

Build errors on Android?

Verify your Application class extends FlutterApplication and imports the correct packages:

import com.vwo.insights.VWOInsights
import com.vwo.insights.exposed.IVwoInitCallback
import com.vwo.insights.exposed.models.ClientConfiguration
import io.flutter.app.FlutterApplication

Support

For additional support or questions:

• Documentation: https://developers.wingify.com/reference/mobile-insights-introduction
• Support Email: [email protected]

Version Information