How to skip validation for array that is empty? - laravel

Question

I have an incoming post data from js like this
[form] => Array (
[name] => 'a form'
[type] => 'form'
...
[children] => Array (
[0] =>
[1] =>
[2] => Array(
[title] => 'first'
[order] => '1'
...
}
[3] => Array(
[title] => 'second'
[order] => '2'
...
)
...
)
...
)
and rules like
[
'form.name' => 'required|string',
'form.type' => 'required|string',
...
'form.children.*.title' => 'requered|string'
'form.children.*.order' => 'requered|integer'
...
]
What is the best way to completely exclude/skip the form.children arrays that are empty and process the ones with data?

Answer 1

Try this:
[
'form.name' => 'required|string',
'form.type' => 'required|string',
...
'form.children.*.title' => 'sometimes|string'
'form.children.*.order' => 'sometimes|integer'
...
]
Sometimes means, if there is something, follow the next rule(s).
https://laravel.com/docs/8.x/validation#validating-when-present
Addition:
For more complex situations, f.ex. you are not interested in an order value if there is no title, makes sense right? Try this:
[
'form.name' => 'required|string',
'form.type' => 'required|string',
...
'form.children.*.title' => 'sometimes|string'
'form.children.*.order' => 'exclude_if:form.children.*.title,null|integer'
...
]
I have never tested/used this on arrays though.

Answer 2

I managed to completely remove the empty arrays just by filtering them out of the request with laravel's prepareForValidation() method and array_filter(). Worked great for me.
protected function prepareForValidation()
{
$this->merge([
"form" => [
"children" => array_filter($this->form["children"])
]
]);
}
#DimitriMostrey's answer worked as well. His answer is a shorter solution without an additional method. Will accept his answer so anyone facing a similar situation can pick the one that suits the most.