Magento Observer Events

Magewire has its own in-process event pipeline (on() / trigger()) that powers Component Hooks. That pipeline is fast and typed, but it's Magewire's. To listen, you write a Mechanism, Feature, or hook.

The SupportMagentoObserverEvents feature bridges that pipeline into Magento's native observer system, so you can react to a component's lifecycle from a plain events.xml observer without a Magewire-specific class required.

How it works

For every event in its map, the feature registers an on() listener that re-dispatches the event as a Magento event named:

magewire_on_<event>

…where <event> is the original name with every non-alphanumeric character replaced by _. So:

Observable events

The Feature maps this fixed list of core events:

• Magewire-specific: magewire:component:construct, magewire:component:reconstruct, magewire:component:build, magewire:view:compile, magewire:setup, magewire:boot.
• Magento-specific: magento:block:render, magento:block:rendered, magento:template:render.
• Component lifecycle: pre-mount, mount.stub, mount, hydrate, update, call, render, render.placeholder, dehydrate, destroy.
• Request/response: request, response.
• Checksum: checksum.generate, checksum.verify, checksum.fail, snapshot-verified.
• Magic methods: __get, __unset, __call.
• Utility: exception, flush-state, profile.

Listening from an observer

Register an observer against the magewire_on_* event as usual:

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
    <event name="magewire_on_mount">
        <observer name="vendor_module_on_magewire_mount"
                  instance="Vendor\Module\Observer\OnMagewireMount"/>
    </event>
</config>

The observer doesn't receive the Magewire arguments directly. Instead it's handed a listener object on which you register a callback. The callback then receives the original event arguments:

namespace Vendor\Module\Observer;

use Magento\Framework\Event\Observer;
use Magento\Framework\Event\ObserverInterface;
use Magewirephp\Magewire\Component;

class OnMagewireMount implements ObserverInterface
{
    public function execute(Observer $observer): void
    {
        $listener = $observer->getData('listener');

        $listener->with(function (Component $component) {
            // Runs with the same arguments the 'mount' event fired with.
        });
    }
}

Before / after semantics

If your callback returns another callable, that returned function runs in the later phase when the triggering code invokes the event's returned dispatcher. Returning nothing reacts only at the initial point:

$listener->with(function (Component $component) {
    // before

    return function ($result) {
        // after: receives the event result, can transform and return it
        return $result;
    };
});

When several observers each contribute a later callback, the Feature runs them as a value pipeline.

When to use this vs Component Hooks

Hooks are the in-framework tool; observer events are the Magento-ecosystem door onto the same lifecycle.

Related

• Component Hooks: the underlying on() / trigger() pipeline.
• Runtime: where magewire:setup / magewire:boot fire.
• Features: how this feature is registered.