Description

Originally described in #38993 (comment), I'd suggest adding a new @Serializer\Context annotation/php attribute/xml and yaml mapping config.

It could accept a normalizationContext, denormalizationContext or both context at once (default option), and perhaps a traverse option to forward the context on deeper nodes if any (when applied on class/object properties).

Example

class Foo
{
    /**
     * @var \DateTime
     *
     * @Serializer\Context({
     *      DateTimeNormalizer::FORMAT_KEY = 'Y-m-d',
     * })
     */
    public $date;
}

This specifically changes the format used to (de)normalize the Foo::$date property while keeping the default context (or the one provided in the (de)serialize call) everywhere else.

Any normalizer with specific context options would benefit from it, as it'll allow to configure anything on a per-case basis.