DataEloquentCast: Give us the ability to merge value with database value

[pqt-jkeller]

The is a possible problem with data loss in common micro-service architectures.
Imagine having a package with eloquent dtos that is used in different microservices.

Now you need a new property in a DTO for 1 certain micro-service. Now Im forced to update all other microservices since old versions would delete this new property on save.

It would be nice, if developers could affect this behaviour to archive something like this:

class DataEloquentCast implements CastsAttributes
{

    public function set($model, string $key, $value, array $attributes): ?string
    {
        if ($value === null) {
            return null;
        }

        if (is_array($value)) {
            $value = ($this->dataClass)::from($value);
        }

        if (! $value instanceof Data) {
            throw CannotCastData::shouldBeData($model::class, $key);
        }

        if (config('data.merge_values_with_database') === true) {
            $decodedOrigin = json_decode($attributes['config'], true);
            $dtoArray = $value->toArray();
            $json = json_encode(
                array_merge_recursive_distinct(
                    $decodedOrigin,
                    $dtoArray
                )
            );
            return $json;
        }
        
       return $value->toJson();
    }
}

[rubenvanassche]

I'm not completely following could you give me a more extensive example with values?