Freemius Purchase Completion JavaScript Callback Filter

purchaseCompleted.php

<?php
    // Add GA tracking only if user opted-in OR if non-WP.org compliant product.
    function my_after_purchase_js( $js_function ) {
        return 'function ( response ) {
            /**
             * Since the user just entered their personal & billing information, agreed to the TOS & privacy,
             * know they are running within a secure iframe from an external domain, they implicitly permit tracking
             * this purchase. So initizlizing GA here (after the purchase), is legitimate.
             */
            ga('create', 'UA-XXXXXXX', 'auto');
            
            console.log("checkout", "purchaseCompleted");
        }';
    }  

    function my_checkout_enrich ( $html ) {
        return '<script type="text/javascript">
            (function() {
                if ( null == ga ) {
                    // Add code to include GA.
                }
            })();
        </script>' . $html;
    }

    my_freemius()->add_filter('checkout/purchaseCompleted', 'my_after_purchase_js');
    my_freemius()->add_filter('templates/checkout.php', 'my_checkout_enrich');
?>

@daigo75 it's the exact same implementation of the example shown here, just a different way to register for the same event handler.

If you dive into the implementation of the checkout's JS code, the callable param provided as purchaseCompleted in the handler.open() will use our postMessage FS.PostMessage.receiveOnce( 'purchaseCompleted' , callable ) implementation.

By using the filter, it does the exact same thing in templates/checkout.

Thanks for the clarification. 👍

Hi,

Below is an example with Google Tag Manager.

my_freemius()->add_filter('checkout/purchaseCompleted', function ($js_function) {
	return "function ( response ) {
	    window.dataLayer = window.dataLayer || []
	    function gtag(){dataLayer.push(arguments)}
	    gtag('js', new Date())
            gtag('config', 'UA-XXXXXXXXXXX', {
	      'cookie_domain': 'example.com'
	    });
           var
		isTrial = (null != response.purchase.trial_ends),
		isSubscription = (null != response.purchase.initial_amount),
		total = isTrial ? 0 : (isSubscription ? response.purchase.initial_amount : response.purchase.gross).toString()
	    window.dataLayer.push({
		'event': 'purchase',
		'price': total
	    })
	}"
});

my_freemius()->add_filter('templates/checkout.php', function ($html) {
	return '<script async src="https://www.googletagmanager.com/gtag/js?id=UA-XXXXXXXXXXX"></script>' . $html;
});

@hqwebs This might be a silly question, but where should I add this code?