| | 3 | * |
| | 4 | * Heartbeat is a simple server polling API that sends XHR requests to |
| | 5 | * the server every 15 seconds and triggers events (or callbacks) upon |
| | 6 | * receiving data. These 'ticks' handle transports for autosaves, post locking, |
| | 7 | * and login-expiration warnings while a user is writing or editing. |
| | 8 | * |
| | 9 | * Available filters in ajax-actions.php: |
| | 10 | * - heartbeat_received |
| | 11 | * - heartbeat_send |
| | 12 | * - heartbeat_tick |
| | 13 | * - heartbeat_nopriv_received |
| | 14 | * - heartbeat_nopriv_send |
| | 15 | * - heartbeat_nopriv_tick |
| | 16 | * @see wp_ajax_nopriv_heartbeat(), wp_ajax_heartbeat() |
| | 17 | * |
| | 18 | * @since 3.6.0 |