In-App Purchase

WTN IAP Plugin for WebtoNative

The WTN IAP Plugin is a sub-plugin for WebtoNative that enables easy handling of iOS and Android in-app purchases (IAP). It provides a mechanism to verify purchases with the App Store and Google Play Store and allows developers to consume the verification result via a custom callback function.

---

Key Features

• In-App Purchase (IAP) Button: Easily integrate IAP functionality into your WordPress site using a shortcode.

• Platform Detection: Automatically detects whether the user is on iOS or Android and processes the purchase accordingly.

• Server-Side Verification: Verifies the purchase receipt with the respective store (App Store or Google Play).

• Callback Integration: Enables developers to handle the verification result with a custom PHP callback function.

---

Configuration

1. Navigate to Settings > WTN IAP (In-App Purchase) in your WordPress admin dashboard.

1. Configure the following options:

• App Store Secret Key:

  • Enter the shared secret from your App Store Connect account. This is required for verifying iOS purchases.

• Callback Function Name:

  • Specify the name of the PHP function that will handle the verification results.

---

Usage

Shortcode

Use the [wtn_iap] shortcode to add an IAP button to your pages or posts.

Attributes

Attribute	Description	Default Value
google_play_id	The product ID of the in-app purchase on Google Play.	''
app_store_id	The product ID of the in-app purchase on the App Store.	''
product_type	The type of product (INAPP for consumable or SUBS for subscription).	INAPP
is_consumable	Whether the product is consumable (true or false).	false

Example

[wtn_iap google_play_id="com.example.app.product" app_store_id="example_product" product_type="INAPP" is_consumable="true"]

---

How It Works

1. IAP Initialization:

   • The user clicks the IAP button.

   • The platform (Android or iOS) is detected using the window.WTN object.

   • The purchase process is initiated using WTN.inAppPurchase.

2. Purchase Handling:

   • After the user completes the purchase, a receipt is generated.

   • The receipt is sent to the WordPress backend for server-side verification.

3. Server-Side Verification:

   • The plugin verifies the receipt with the respective store's API.

   • A success or failure message is returned based on the verification result.

4. Callback Execution:

   • If a custom callback function is configured, it is invoked with the platform and verification data.

---

Server-Side Callback Integration

Developers can consume the IAP verification result by implementing a custom PHP callback function.

Callback Function Requirements

• Function Name: The function's name must match the one configured in the plugin settings.

• Parameters:

  • $platform: The platform of the purchase (ios or android).

  • $receipt_data: An array containing:

    • receipt: The raw receipt data.

    • verification_result: The verification result returned by the respective store's API.

Example Callback Function for Verification

Users must define a callback function in their theme’s functions.php or a custom plugin. This function will process the verification result and take appropriate actions, such as granting access to content or updating the user’s status.

function my_custom_callback($platform, $receipt_data) {
    // Log the platform and data for debugging
    error_log("Platform: $platform");
    error_log("Verification Data: " . print_r($receipt_data, true));

    // Process the verification result
    $receipt = $receipt_data['receipt'];
    $verification_result = $receipt_data['verification_result'];

    if ($verification_result['success']) {
        // Example: Grant access to premium content
        $user_id = get_current_user_id();
        update_user_meta($user_id, 'premium_access', true);
        error_log("User ID $user_id granted premium access.");
    } else {
        error_log("Verification failed: " . $verification_result['message']);
    }
}
add_action('simple_iap_callback', 'my_custom_callback');

---

Frontend Integration

JavaScript Integration

The plugin includes a JavaScript file (wtn-iap.js) that handles the IAP process on the client side.

1. IAP Button:

   • When the button is clicked, the WTN.inAppPurchase a method is invoked with the product details.

2. Purchase Callback:

   • The purchase callback (paymentCallback) processes the response and sends the receipt to the server via an AJAX request.

3. Server Response Handling:

   • The front end displays appropriate success or error messages based on the server's response.

Example Workflow

1. The user clicks the "Buy Now" button.

2. The IAP process starts, and the receipt is obtained.

3. The receipt is sent to the WordPress backend for verification.

4. A success or error message is displayed based on the verification result.

---

Error Handling

Frontend Errors

• Payment Failure: Alerts the user if the purchase fails.

• Invalid Response: Logs and displays an error message if the server returns an invalid response.

Backend Errors

• Missing App Store Secret: Returns an error if the secret key is not configured.

• Invalid Receipt: Returns an error if the receipt verification fails.

For more reference

In App Purchase - iOS Setup | WebToNativedocs.webtonative.com

In App Purchase - iOS Setup

In App Purchase - Android Setup | WebToNativedocs.webtonative.com

In App Purchase - Android Setup

In App Purchase - iOS Integration | WebToNativedocs.webtonative.com

In App Purchase - iOS Integration

In App Purchase - Android Integration | WebToNativedocs.webtonative.com

In App Purchase - Android Integration

---

This documentation provides a comprehensive guide for using the Simple IAP Plugin and customizing it to meet specific requirements.