[TwigComponent] Add #[ComponentCache] attribute for persistent computed properties

[xDeSwa]

Q	A
Bug fix?	no
New feature?	yes
Deprecations?	no
Documentation?	yes
Issues	#
License	MIT

Description

This PR introduces the #[ComponentCache] attribute, which supercharges the existing computed properties system by adding persistent cross-request caching using Symfony Cache.

While the current computed proxy memoizes results during a single request, there was no native way to persistently cache heavy component methods (like complex database queries or API calls) without polluting the component with manual CachePool injections.

With this feature, developers can easily cache the return value of any component method across requests directly from the component class, while keeping the Twig syntax ({{ computed.method }}) exactly the same.

Usage Example

use Symfony\UX\TwigComponent\Attribute\AsTwigComponent;
use Symfony\UX\TwigComponent\Attribute\ComponentCache;

#[AsTwigComponent]
class DashboardStats
{
    // Caches the return value in the 'cache.app' pool for 1 hour.
    #[ComponentCache(expiresAfter: 3600, tags: ['dashboard_stats'])]
    public function getHeavyMetrics(): array
    {
        return $this->repository->calculateComplexMetrics();
    }
}

In the template, it is accessed seamlessly via the existing proxy:

{# The first visitor triggers the DB query. For the next hour, it's served from the persistent cache in 0ms. #}
Total Users: {{ computed.heavyMetrics.totalUsers }}

Key Features

• Auto-Key Generation: If no key is provided, a unique cache key is automatically generated using the component's class name, method name, and a hash of its public properties (get_object_vars()). This ensures the cache invalidates safely when LiveComponent props (e.g., page, filters) change!
• Dynamic Pool Support: Supports injecting specific cache pools (e.g. pool: 'cache.redis'). Falls back to cache.app by default.
• Tags & Expiration: Supports tags (for TagAware adapters) and expiresAfter (seconds or DateInterval).
• LiveComponent Compatible: Works flawlessly inside LiveComponents since it hooks directly into ComputedPropertiesProxy.