Laravel 5.5 / Validator / Custom rules - laravel

Question

(edited to clearer purpose)
I discovered Laravel some months ago and I followed some Laracast videos. Now, I'm stuck with a problem of custom Validator.
I've got normal and permanent rules (date | required | min / max) to verify my form request. This part works.
But I've got a custom validation which could be verified as a normal rule IF one of the request parameter - select1 - is set to 1 (for exemple).
I read a dozen of explanation but nothing clear enough.
So, let start with my code. Thank you for your indulgence...
My question is into the customTest function on the bottom.
Thank you,
1/ I made a new Request with
php artisan make:controller priceRequest.php
2/ I made some rules and changed some lines.
public function authorize()
{
return true;
}
// Permanent RULES
public function rules()
{
$rules = [
'field1' => 'required|min:1|max:15',
'field2' => 'required',
'date1' => 'required|date',
'select1' => 'required',
];
return $rules;
}
Then I integrated a new function to perform a custom verification
public function withValidator($validator) {
$validator->after(function ($validator) {
if (!$this->customTests($this->request->get('data'))){
$validator->errors()->add('custom', 'Something is wrong');
}
});
}
Finally, I wrote the customTests function and it is inside this one I'm stuck !!
public function customTests($data) {
if ($data['select1'] == 1) {
// HERE MY QUESTION
// I'd like to verify that $data['date2']
// is a date and is set. So, I'd like to
// add a rule to rules (has I made with
// 'date1' => 'required|date',
// and return TRUE if the rule match or
// FALSE
}
}

Answer 1

So, I found the solution to my problem.
I made a mistake and a confusion because I tried to add the new rule into the ->after() function.
So, the correct code is the following :
public function withValidator($validator)
{
$validator->sometimes('ticket.price', 'required|integer|min:0.1', function ($input) {
if ($any_condition_who_need_to_verify_new_rule) {
return true;
}
else {
# Everything is perfect, this rule cas be omitted
}
$validator->after(function ($validator) use ($ticket) {
/* New test more complicated which cannot be
tested with a rule */
if ($this_test_is_complex_and_fails) {
$validator->errors()->add('validateTicket', 'This is another problem');
return false;
}
});
return $validator;
}