ave-cms/help/en/helpers/Hooks.md

Hooks - low-level dispatcher

App\Helpers\Hooks - low-level registration and sending of events/filters. Stable system points, contexts and connection via module are described in section “Hooks and events”. Two types:

• action - “event”: handlers perform side effects, do nothing return.
• filter - “filter”: the value is passed through the chain and returned changed.

use App\Helpers\Hooks;

---

Subscribe

###add($name, $function, $priority = 10) Sign the handler. Lower priority = earlier executed.

once($name, $function, $priority = 10) - will work once.

remove($name, $function, $priority = 10) — unsubscribe.

Hooks::add('reviews.title', function ($title) {
    return trim((string) $title);
}, 10);

---

Challenge

###action($name, $arguments = '') Execute all event handlers. If there are no subscribers, it will return $arguments as is.

Hooks::action('reviews.rebuilt', $summary);

###filter($name, $value) Pass $value through the filter chain and get the result. No subscribers - will return the original value.

Hooks::add('document.title', function ($t) { return trim($t); });
Hooks::add('document.title', function ($t) { return mb_strtoupper($t, 'UTF-8'); }, 20);

$title = Hooks::filter('document.title', $rawTitle);

---

Introspection

Method	Destination
exists($name)	Is the hook registered?
has($hook, $priority = 10)	Is there a priority handler?
current()	The name of the currently executing hook.
debug()	Debug dump of subscriptions.
trace(), enableTrace()	Structured runtime trace for a secure debugger.
resetRuntime()	Clear the runtime log between requests of a long-lived process.
init()	System initialization (called by the kernel).

---

action vs filter - how to choose

Need...	Method
Do something in response to an event (clear cache, log)	action
Change/add a value and return it	filter

The order of execution is determined by priority (ascending). Same priority - in order of addition.