edd-heartbeat-demo.php

<?php
/**
 * Plugin Name: EDD Heartbeat API test plugin
 * Description: Demonstrates how to use the Heartbeat API to update the payments count on the dashboard
 */

// Load the heartbeat JS
function edd_heartbeat_enqueue( $hook_suffix ) {
    // Make sure the JS part of the Heartbeat API is loaded.
    wp_enqueue_script( 'heartbeat' );
    add_action( 'admin_print_footer_scripts', 'edd_heartbeat_footer_js', 20 );
}
add_action( 'admin_enqueue_scripts', 'edd_heartbeat_enqueue' );

// Inject our JS into the admin footer
function edd_heartbeat_footer_js() {
    global $pagenow;

    // Only proceed if on the dashboard
    if( 'index.php' != $pagenow )
        return;
?>
    <script>
    (function($){

        // Hook into the heartbeat-send
        $(document).on('heartbeat-send', function(e, data) {
            data['edd_heartbeat'] = 'dashboard_summary';
        });

        // Listen for the custom event "heartbeat-tick" on $(document).
        $(document).on( 'heartbeat-tick', function(e, data) {

            // Only proceed if our EDD data is present
            if ( ! data['edd-payment-count'] )
                return;

            // Log the response for easy proof it works
            console.log( data['edd-payment-count'] );

            // Update sale count and bold it to provide a highlight
            $('.edd_dashboard_widget .b.b-sales').text( data['edd-payment-count'] ).css( 'font-weight', 'bold' );

            // Return font-weight to normal after 2 seconds
            setTimeout(function(){
                $('.edd_dashboard_widget .b.b-sales').css( 'font-weight', 'normal' );;
            }, 2000);

        });
    }(jQuery));
    </script>
<?php
}

// Modify the data that goes back with the heartbeat-tick
function edd_heartbeat_received( $response, $data ) {

    // Make sure we only run our query if the edd_heartbeat key is present
    if( $data['edd_heartbeat'] == 'dashboard_summary' ) {

        // Retrieve payment count
        $payments = edd_count_payments();

        // Send back the number of complete payments
        $response['edd-payment-count'] = number_format_i18n( $payments->publish );

    }
    return $response;
}
add_filter( 'heartbeat_received', 'edd_heartbeat_received', 10, 2 );