Thank You to the answer!
That's the solution in the model:
Code:
protected function initialize()
{
$this->validationRules = $this->SetRules();
}
protected function SetRules()
{
for ($i = 0; $i < config('MyConfig/Sales')->nb_salesline; $i++) {
$salesline_no = $i + 1;
$rules["salesline_item_{$i}"] = [
'label' => 'Rules.salesline.item',
'rules' => "permit_empty|string|max_length[50]|required_with[salesline_quantity_{$i}]",
];
$rules["salesline_storage_{$i}"] = [
'label' => 'Rules.salesline.storage',
'rules' => "permit_empty|string|max_length[50]|required_with[salesline_item_{$i}]",
];
$rules["salesline_quantity_{$i}"] = [
'label' => 'Rules.salesline.quantity',
'rules' => "permit_empty|decimal|max_length[10]|required_with[salesline_storage_{$i}]",
];
}
return $rules;
}