GeezerVison

Problem

HookableLiveComponentTrait dehydrates the hookableMetadata LiveProp to the hook name, the configuration and the prefixes only. On a live re-render, the hookable context is empty:

• hookable_metadata.context.* is empty in the component template;
• nested {% hook %} calls don't get the parent context;
• the conditions and @= expressions of the nested hookables see an empty _context.

The context can't simply be serialized into the LiveProp: it usually holds objects (grid views, resource metadata, entities, forms), which are too large for the payload and must not be readable by the client.

Solution

Two overridable methods on the trait. Both do nothing by default, so there's no BC break, and the payload only changes when a component lists keys:

/** @return array<string> scalars, nulls or arrays of them; sent to the client */
protected function getDehydratedHookableContextKeys(): array { return []; }

/** @return array<string, mixed> merged on top of the hookable context at render time */
protected function provideHookableContext(): array { return []; }

• provideHookableContext() is applied at render time, on the first render and on every re-render, through #[ExposeInTemplate(getter: ...)]. It runs after the live actions, and its values are never dehydrated. Use it to give back objects built from the component's own LiveProps.
• getDehydratedHookableContextKeys() keeps plain values in the LiveProp. The LiveProp isn't writable, so the checksum covers them. Values that aren't scalars, nulls or arrays of them throw a LogicException.
• Adds HookableMetadata::withContext().

Example, from the Sylius admin live grid (Sylius/Sylius#19289):

protected function provideHookableContext(): array
{
    return [
        'resources' => $this->getGridView(),
        'metadata' => $this->getMetadata(),
        'live_grid' => true,
        'are_criteria_set' => $this->hasActiveCriteria(),
    ];
}

With this, the component template goes from {% hook 'grid' with { resources: grid, metadata, live_grid: true, are_criteria_set: this.hasActiveCriteria() } %} to {% hook 'grid' %}.

Notes

• The DataBagHydrationExtension (unregistered) is left untouched: it would dehydrate the whole bag, objects included.
• Tests: unit tests for the trait, plus a functional test that does a real re-render with InteractsWithLiveComponents. That's why symfony/browser-kit and symfony/css-selector are added to the Twig Hooks require-dev; the root composer.json already has both.