Initialization

To create a VWO Client instance, you need to initialize the VWO FE Go SDK. This client instance serves as the core interface for conducting Feature Experimentation(A/B and personalization) within your application.

Usage

package main

import (
    "fmt"
    "log"

    vwo "github.com/wingify/vwo-fme-go-sdk"
)

func main() {
    // Initialize VWO SDK with your account details
    options := map[string]interface{}{
        "sdkKey":    "32-alpha-numeric-sdk-key", // Replace with your SDK key
        "accountId": "123456",                   // Replace with your account ID
    }

    // Initialize VWO vwoClient
    vwoClient, err := vwo.Init(options)
    if err != nil {
        log.Fatalf("Failed to initialize VWO client: %v", err)
    }
}

The Init function is called with the sdkKeyand accountId. It initializes and returns a VWO Client ObjectvwoClient, which can be used to perform feature
This client object allows you to run experiments, track events, and enable/disable feature flags.

Parameter Definitions

Poll Interval (Keeping VWO client up-to-date)

When you initialize the vwoClient on your server, it pulls the latest configurations you've done in the VWO application.
If/when you make any changes to the feature flags or rules within VWO after the vwoClient has been initialized in your server, there needs to be some way to update your vwoClient with the latest settings from VWO. This can be done via polling.

The poll interval is an optional parameter that allows the SDK to automatically fetch and update settings from the VWO server at specified intervals. Setting this parameter ensures your application always uses the latest configuration.

options := map[string]interface{}{
    "sdkKey":       "32-alpha-numeric-sdk-key",
    "accountId":    "123456",
    "pollInterval": 60000, // Set the poll interval to 60 seconds
}

vwoInstance, err := vwo.Init(options)

Logger

VWO by default logs all ERROR level messages to your server console. To gain more control over VWO's logging behavior, you can use the logger parameter in the init configuration.

options := map[string]interface{}{
    "sdkKey":    "32-alpha-numeric-sdk-key",
    "accountId": "123456",
    "logger": map[string]interface{}{
        "level": "DEBUG",
    },
}

vwoInstance, err := vwo.Init(options)

Please click here for more advanced logger options.

Storage

By default, the SDK operates in stateless mode, evaluating flags on each getFlag call. To improve performance and consistency, you can use a custom storage mechanism to cache decisions, ensuring stable user experiences and reducing application load.

// Use in initialization
options := map[string]interface{}{
    "sdkKey":    "32-alpha-numeric-sdk-key",
    "accountId": "123456",
    "storage":   customStorage
}

vwoInstance, err := vwo.Init(options)

Please click here to learn more about storage implementation.

Gateway Service

The VWO FE Gateway Service enhances Feature Experimentation (FE) SDKs by enabling pre-segmentation based on user location and user agent. It ensures minimal latency and improved security. The service can be customized via the gateway_service parameter during initialization.

options := map[string]interface{}{
    "sdkKey":    "32-alpha-numeric-sdk-key",
    "accountId": "123456",
    "gatewayService": map[string]interface{}{
        "url": "http://custom.gateway.com",
    },
}

vwoInstance, err := vwo.Init(options)

Please click here to learn more about the VWO Gateway service.

Integrations

VWO FE SDKs provide seamless integration with third-party tools like analytics platforms, monitoring services, customer data platforms (CDPs), and messaging systems. This is achieved through a simple yet powerful callback mechanism that receives VWO-specific properties and can forward them to any third-party tool of your choice.

options := map[string]interface{}{
    "sdkKey":       "32-alpha-numeric-sdk-key",
    "accountId":    "123456",
    "integrations": map[string]interface{}{
        "Callback": func(properties map[string]interface{}) {
            // implement your custom logic here
            fmt.Printf("Integration callback called with properties: %+v\n", properties)
        },
    },
}

vwoInstance, err := vwo.Init(options)

Please click here to learn more about Integrations,.

Initialization with Explicit Settings

The SDK provides the ability to reduce initialization time by allowing users to explicitly pass in settings instead of fetching them automatically. This can be especially useful in environments where you need to optimize for faster setup or if you already have the necessary settings retrieved from a remote server.
Please refer to this document for more information on retrieving settings.

var localSettings = '{
    "accountId": 123456,
    "sdkKey": '32-alpha-numeric-sdk-key',
    "features": {
        // features json here
    },
    "campaigns": {
        // campaigns json here
    },
    "version": 1,
}'

options := map[string]interface{}{
    "sdkKey":       "32-alpha-numeric-sdk-key",
    "accountId":    "123456",
    "settings": localSettings
}

vwoInstance, err := vwo.Init(options)

Retry Config

The retryConfig parameter allows you to customize the retry behavior for network requests. This is particularly useful for applications that need to handle network failures gracefully with exponential backoff strategies.

options := map[string]interface{}{
    "sdkKey":    "32-alpha-numeric-sdk-key",
    "accountId": "123456",
    "retryConfig": map[string]interface{}{
        "shouldRetry":       true,  // Enable retries
        "maxRetries":        5,     // Retry up to 5 times
        "initialDelay":      3,     // Wait 3 seconds before first retry
        "backoffMultiplier": 2,     // Double the delay for each subsequent retry
    },
}

vwoInstance, err := vwo.Init(options)

Please click here to learn more about retry configuration.