Validation: combination of required_if with prohibited_unless

[firebed]

I have come across a lot of times in my projects where a field under validation is required if another field has a specific value, and the same field under validation is prohibited unless that condition is met.

For example I have an eshop and I want to adjust a product's stock with a specific adjustment reason.
The adjustment reason might be something like 1 => Damaged, 2 => Theft or loss, 3 => Promotion, 99 => Other.
If the reason code is 99 I expect the user to provide the other adjustment reason title, otherwise the user should be prohibited from providing a custom reason title.

Currently, alongside with custom rule, another possible way to achieve this is to use a combination of required_if and prohibited_unless. This is a part of my rules:

'quantity' => ['required', 'integer'],
'adjustment_reason' => ['required', 'in:1,2,3,99'],
'other_adjustment_reason_title' => ['nullable', 'required_if:adjustment_reason,99', 'prohibited_unless:adjustment_reason,99'],

The above will yield one of the following errors based on the adjustment_reason

[
    'adjustment_reason' => 99,
    'other_adjustment_reason_title' => ''
];

Error: `The other_adjustment_reason_title field is required when adjustment_reason is 99.`

[
    'adjustment_reason' => 1,
    'other_adjustment_reason_title' => 'Return retail sale'
];

Error: `The other_adjustment_reason_title field is prohibited when adjustment_reason is 1.`

This is totally ok and is working. However I have a lot of such situations and I end up repeating myself all over the place which makes the project harder to maintain.

So, my solution to this is a new validation rule exclusive_*:

Before:
'other_adjustment_reason_title' => ['nullable', 'required_if:adjustment_reason,99', 'prohibited_unless:adjustment_reason,99'],

After:
'other_adjustment_reason_title' => ['nullable', 'exclusive_if:adjustment_reason,99'],

The whole set: exclusive_if, exclusive_unless, exclusive_with, exclusive_without, Rule::exclusiveIf().
I would love to make a PR on this but don't know if it is something worth working on. Any thoughts?

[shaedrich]

A similar case is with required_with + prohibited_without resp. required_without + prohibited_with. The rules have to be duplicated (reversed) for two fields each time. Sure, changing this, is a little more complicated, since the field names are keys, but maybe, there's also a solution

[firebed]

required_with + prohibited_without would be replaced by exclusive_with, meaning the field under validation is required when another field is present, and prohibited otherwise.

'appointment_date' => ['required', 'date'],
'appointment_place' => ['nullable', 'exclusive_with:appointment_date'],

If user provides appointment_date he must also provide appointment_place.
If user doesn't provide appointment_date he must also not provide appointment_place.

Same with required_without + prohibited_with would be replaced by exclusive_without, meaning the field under validation is required when another field is not present, and prhibited if the another field is present.

'primary_contact' => ['nullable', 'string'],
'alternate_contact' => ['nullable', 'exclusive_without:primary_contact'],

If user provides primary_contact he must not provide alternate_contact.
If user doesn't provide primary_contact he must provide alternate_contact.

[shaedrich]

Yep, sounds good 👍🏻