Validate array of inputs in form in Laravel 5.7

In fact, it's enough to use:

$validator = Validator::make($request->all(),[
        'items' => 'required|array'
    ]);

The changes made:

• use items instead of items.* - you want to set rule of general items, if you use items.* it means you apply rule to each sent element of array separately
• removed size:1 because it would mean you want to have exactly one element sent (and you want at least one). You don't need it at all because you have required rule. You can read documentation for required rule and you can read in there that empty array would case that required rule will fail, so this required rule for array makes that array should have at least 1 element, so you don't need min:1 or size:1 at all

You can check it like this:

$validator = Validator::make($request->all(), [
    "items"    => "required|array|min:1",
    "items.*"  => "required|string|distinct|min:1",
]);

In the example above:

• "items" must be an array with at least 1 elements.
• Values in the "items" array must be distinct (unique) strings, at least 1 characters long.

You can use a custom rule with a closure.

https://laravel.com/docs/5.7/validation#custom-validation-rules

To check if an array has all null values check it with array_filter which returns false if they're all null.

So something like...

  $request->validate([

    'items' => [
      // $attribute = 'items', $value = items array, $fail = error message as string
       function($attribute, $value, $fail) {
         if (!array_filter($value)) {
           $fail($attribute.' is empty.');
         } 
       },
     ]
   ]);

This will set the error message: 'items is empty."

Knowing you are using the latest version of Laravel, I really suggest looking into Form Request feature. That way you can decouple validation from your controller keeping it much cleaner.

Anyways as the answer above me suggested, it should be sufficient for you to go with:

'items' => 'required|array'

Just Do it normally as you always do:

 $validator = Validator::make($request->all(),[
    'items' => 'required'
  ]);

You should try this:

$validator = $request->validate([
    "items"    => "required|array|min:3",
    "items.*"  => "required|string|distinct|min:3",
]);