DoesNotExist validation rule

[alberto-bottarini]

My scenario:

Users can create custom events setting start_date, end_date and topic.
Events cannot overlap themself.

For example I created an "holiday" event from 2022/08/01 to 2020/08/20. I cannot create another event that starts, for example, on 2022/08/15 because this new one will overlap with "holiday" event.

I cannot validate this situation using custom validator becase:

• Exists rule has a positive approach, it requires that a certain record exists in database
• Unique rule has a negative approach (and it is useful) but it automatically add a condition where $field <> $value that in my case is not right.

I would like to have something like this:

'start_date' => [
    'required',
    'date_format:Y-m-d',
    'after:today', 
    Rule::doesNotExists(Event::class)->where(function ($query) {
        return $query->where('start_date', '<=', $this->start_date)
            ->where('start_date', '>=', $this->start_date);
        })
]

This new rule should pass if a particular query returns no records, without setting an automatic where condition as Unique rule does.

What do you think?