[TwigComponent] Build the exposed properties without a generator

[Kocal]

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

getProperties() runs once per component render and allocated a Generator plus an iterator_to_array() pass on every call. extractProperties() was private, had a single caller, and that caller materialised it immediately, so nothing was ever lazy.

Build the array directly and drop the generator. Both shapes get faster, and there is no special case for either.

200k calls, component with five public properties and no #[ExposeInTemplate]: ~88 ms -> ~37 ms. Same count on a component that does use the attribute: ~207 ms -> ~162 ms. On a more realistic scale, an admin CRUD page with a table of 50 rows (6 columns, 2 buttons and a badge each, so 501 component renders) goes from 0.24 ms to 0.12 ms per page: a fraction of a millisecond, but for free.

Benchmarked from the repository root with blackfire run symfony php bench.php:

<?php
require __DIR__.'/src/TwigComponent/vendor/autoload.php';

use Symfony\Component\PropertyAccess\PropertyAccess;
use Symfony\UX\TwigComponent\Attribute\ExposeInTemplate;
use Symfony\UX\TwigComponent\ComponentProperties;

// The overwhelmingly common shape: public props, no #[ExposeInTemplate].
class PlainComponent
{
    public string $title = 'Hello';
    public string $type = 'success';
    public bool $dismissible = true;
    public int $count = 3;
    public ?string $icon = null;
}

// The other shape, to check it does not regress.
class ExposingComponent
{
    public string $title = 'Hello';

    #[ExposeInTemplate('label')]
    private string $name = 'ryan';

    public function getName(): string
    {
        return $this->name;
    }

    #[ExposeInTemplate]
    public function computedThing(): string
    {
        return 'computed';
    }
}

$properties = new ComponentProperties(PropertyAccess::createPropertyAccessor());

foreach (['plain' => new PlainComponent(), 'with attributes' => new ExposingComponent()] as $label => $component) {
    $properties->getProperties($component, true);

    $start = hrtime(true);
    for ($i = 0; $i < 20000; ++$i) {
        $properties->getProperties($component, true);
    }
    printf("%-18s -> %8.2f ms\n", $label, (hrtime(true) - $start) / 1e6);
}

Blackfire:

• before (547ms wall / 543ms CPU): https://app.blackfire.io/envs/5f4f9a62-eaa0-45ee-b7b3-a1b879f550e9/profiles/d02bf215-b6cb-407e-856e-413a5138c061/graph
• after (338ms wall / 337ms CPU): https://app.blackfire.io/envs/5f4f9a62-eaa0-45ee-b7b3-a1b879f550e9/profiles/80b41440-2da8-435f-b55f-aade7aa958a4/graph
• diff: https://app.blackfire.io/envs/5f4f9a62-eaa0-45ee-b7b3-a1b879f550e9/profiles/compare/d02bf215-b6cb-407e-856e-413a5138c061...80b41440-2da8-435f-b55f-aade7aa958a4/graph

Analysis, implementation and benchmarks by Claude Opus 5.