gistfile1.txt

<?php

namespace JVZApprovalPlugin;

use stdClass;
use WP_Error;

DEFINE('theme_update_api', 'http://www.licenseengine.com/updates');

class themeUpdater
{

    function __construct()
    {

        $this->hook();
    }

    private function hook()
    {

        add_filter('pre_set_site_transient_update_themes', array(&$this, 'check_for_update'));
    }

    public function check_for_update($transient)
    {

        if (empty($transient->checked))
        {
            return $transient;
        }

        global $wp_version;

        $theme_data = wp_get_theme();
        $theme_slug = $theme_data->get_template();

        $args = ['slug' => $theme_slug, 'version' => $wp_version];

        $request_string = array(
            'body' => array(
                'action' => 'plugin_information',
                'request' => serialize($args),
                'api-key' => md5(get_bloginfo('url'))
            ),
            'user-agent' => 'WordPress/'.$wp_version.'; '.get_bloginfo('url')
        );

        $request = wp_remote_post(theme_update_api, $request_string);

        if (is_wp_error($request))
        {
            $res = new WP_Error('plugins_api_failed',
                __('An Unexpected HTTP Error occurred during the API request.</p> <p><a href="?" onclick="document.location.reload(); return false;">Try again</a>'),
                $request->get_error_message());
        }
        else
        {

            $res = unserialize($request['body']);

            if ($res===false)
            {
                $res = new WP_Error('plugins_api_failed', __('An unknown error occurred'), $request['body']);
            }
        }
        $object = new stdClass();

        foreach ($res as $key => $value)
        {
            $object->$key = $value;
        }

        $transient->response[$theme_slug] = array(
            'new_version' => $object->new_version,
            'package' => $object->package,
            'url' => $object->description
        );

        return $transient;
    }

}

new themeUpdater();