WordPress Plugin autoupdate API integration code example

The first part of the code consist of few constants definition which are being used later within the code.

//the url where the WooCommerce Software License plugin is being installed
define('SL_APP_API_URL',      'http://YourDomainWhereSoftwareManagement.com/index.php');

//the Software Unique ID as defined within product admin page
define('SL_PRODUCT_ID',           'APTO');

//A code variable constant is required, which is the user application code version. This will be used by API to compare against the new version on shop server.
define('SL_VERSION', '1.4.2');

$protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
define('SL_INSTANCE',             str_replace($protocol, "", get_bloginfo('wpurl')));

A plugin auto-update code can be inserted within the plugin, here is an example:

    class WOOSL_CodeAutoUpdate
        {

            // URL to check for updates, this is where the index.php script goes

            public $api_url;

            private $slug;
            public $plugin;
            
            private $API_VERSION;


            function __construct($api_url, $slug, $plugin)
                {
                    $this->api_url  =   $api_url;
                    $this->slug     =   $slug;
                    $this->plugin   =   $plugin;
                    
                    //use laets available API 
                    $this->API_VERSION =   1.1;
                    
                }

            public function check_for_plugin_update($checked_data)
                {
                     if ( !is_object( $checked_data ) ||  ! isset ( $checked_data->response ) )
                        return $checked_data;
                     
                     $request_string = $this->prepare_request('plugin_update');
                     if($request_string === FALSE)
                        return $checked_data;
                     
                     global $wp_version;
                     
                     // Start checking for an update
                     $request_uri = $this->api_url . '?' . http_build_query( $request_string , '', '&');
                     
                     //check if cached
                     $data  =   get_site_transient( 'my-custom-plugin-check_for_plugin_update_' . md5( $request_uri ) );
                     if  ( $data    === FALSE )
                         {
                             $data = wp_remote_get( $request_uri, array(
                                                                                'timeout'     => 20,
                                                                                'user-agent'  => 'WordPress/' . $wp_version . '; ' . get_bloginfo( 'url' ),
                                                                                ) );
                             
                             if(is_wp_error( $data ) || $data['response']['code'] != 200)
                                return $checked_data;
                                
                             set_site_transient( 'my-custom-plugin-check_for_plugin_update_' . md5( $request_uri ), $data, 60 * 60 * 4 );
                             
                         }
                                                  
                     $response_block = json_decode($data['body']);
                      
                     if(!is_array($response_block) || count($response_block) < 1)
                        return $checked_data;
                     
                     //retrieve the last message within the $response_block
                     $response_block = $response_block[count($response_block) - 1];
                     $response = isset($response_block->message) ? $response_block->message : '';
                     
                     if (is_object($response) && !empty($response)) // Feed the update data into WP updater
                         {
                             $response  =   $this->postprocess_response( $response );
                             
                             $checked_data->response[$this->plugin] = $response;
                         }
                     
                     return $checked_data;
                }

            public function plugins_api_call($def, $action, $args)
                {
                     if (!is_object($args) || !isset($args->slug) || $args->slug != $this->slug)
                        return $def;
    
                     $request_string = $this->prepare_request($action, $args);
                     if($request_string === FALSE)
                        return new WP_Error('plugins_api_failed', __('An error occour when try to identify the pluguin.' , 'woo-global-cart') . '&lt;/p> &lt;p>&lt;a href=&quot;?&quot; onclick=&quot;document.location.reload(); return false;&quot;>'. __( 'Try again', 'woo-global-cart' ) .'&lt;/a>');;
                     
                     global $wp_version;
                     
                     $request_uri = $this->api_url . '?' . http_build_query( $request_string , '', '&');
                     $data = wp_remote_get( $request_uri, array(
                                                                        'timeout'     => 20,
                                                                        'user-agent'  => 'WordPress/' . $wp_version . '; ' . get_bloginfo( 'url' ),
                                                                        ) );
                     
                     if(is_wp_error( $data ) || $data['response']['code'] != 200)
                        return new WP_Error('plugins_api_failed', __('An Unexpected HTTP Error occurred during the API request.' , 'woo-global-cart') . '&lt;/p> &lt;p>&lt;a href=&quot;?&quot; onclick=&quot;document.location.reload(); return false;&quot;>'. __( 'Try again', 'woo-global-cart' ) .'&lt;/a>', $data->get_error_message());
                     
                     $response_block = json_decode($data['body']);
                     //retrieve the last message within the $response_block
                     $response_block = $response_block[count($response_block) - 1];
                     $response = $response_block->message;
                     
                     if (is_object($response) && !empty($response))
                         {
                             $response  =   $this->postprocess_response( $response );
                             
                             return $response;
                         }
                }

            public function prepare_request($action, $args = array())
                {
                    global $wp_version;
                    
                    return array(
                        'woo_sl_action'         => $action,
                        'version'               => SL_VERSION,
                        'product_unique_id'     => SL_PRODUCT_ID,
                        'licence_key'           => LICENSE_KEY,
                        'domain'                => SL_INSTANCE,
                        'wp-version'            => $wp_version,
                        
                        'api_version'           => $this->API_VERSION
                    );
                }
            
            private function postprocess_response( $response )
                 {
                     //include slug and plugin data
                     $response->slug    =   $this->slug;
                     $response->plugin  =   $this->plugin;
                     
                     //if sections are being set
                     if ( isset ( $response->sections ) )
                        $response->sections = (array)$response->sections;
                     
                     //if banners are being set
                     if ( isset ( $response->banners ) )
                        $response->banners = (array)$response->banners;
                       
                     //if icons being set, convert to array
                     if ( isset ( $response->icons ) )
                        $response->icons    =   (array)$response->icons;
                     
                     return $response;
                     
                 }
        }

        function WOOSL_run_updater()
            {
                $wp_plugin_auto_update = new WOOSL_CodeAutoUpdate(SL_APP_API_URL, 'plugin-slug', 'plugin-folder/plugin-filename.php');

                // Take over the update check

                add_filter('pre_set_site_transient_update_plugins', array(
                    $wp_plugin_auto_update,
                    'check_for_plugin_update'
                ));

                // Take over the Plugin info screen

                add_filter('plugins_api', array(
                    $wp_plugin_auto_update,
                    'plugins_api_call'
                ) , 10, 3);
            }

        add_action('after_setup_theme', 'WOOSL_run_updater');