[Map] Improve backend performance when rendering HTML "view" attribute

[Kocal]

Q	A
Bug fix?	no
New feature?	no
Issues	Fix #...
License	MIT

My intuition was right, I knew there was some back optimization to be done on Map :)

For the context, I've created a Map with 1000 Marker and InfoWindow (it represents the first 1000 cities from France in alphabetical order, but it can also be a store-locator, etc...)

The code looks like:

$map = new Map();
$map->center(new Point(48.8566, 2.3522));
$map->zoom(6);

$cities = require_once __DIR__.'/../../config/cities.php';

foreach ($cities as $i => $city) {
    $map->addMarker(
        new Marker(
            position: new Point($city['latitude'], $city['longitude']),
            title: $city['label'],
            infoWindow: new InfoWindow(
                headerContent: '<b>'.$city['label'].'</b>',
                content: 'Welcome in '.$city['label'],
                opened: $i === 300,
            ),
        )
    );
}

Before

Before this PR, when profiling the page with Blackfire, we can see that StimulusAttributes#toString() takes ~62% of the response time (~222ms), because of the Twig escaping code (preg_replace_callback and ord()):

This is long because our view attribute can be very big, it contains a lot of data. But, since it's an array with a known structure, etc..., maybe we can... not use Twig escaping strategy?

Note
I will open an issue on Twig, maybe it already exists, but it may be interesting to see if we can improve things at the root.

EDIT: opened twigphp/Twig#4322

Now

I've removed view' => $map->toArray() from the StimulusAttributes, and added 'data-symfony--ux-'.$this->getName().'-map--map-view-value="'.htmlentities(json_encode($map->toArray(), flags: JSON_THROW_ON_ERROR)).'"' at the final rendering place.

When profiling the page with Blackfire, I can see an improvment of ~63% on the response time 🚀 :

I'm not 100% sure, but I believe htmlentities and json_encode are enough for our usecase? I mean, it still works, and HTML in InfoWindow still works too:

[Kocal]

Closing in favor of a new PR :)