laravel validation, Rule::exists or Rule::in-CodePudding

I want to validate sequence of items. In my idea sequence field must be exists in database sequence column or must be one plus more than maximum of present sequence. I have this code in view:

<select id="sequence" name="sequence" value="{{ old('sequence') }}">
  @foreach ($items = App\Models\Item::all()->sortBy('sequence') as $item)
    <option value="{{ $item->sequence }}">{{ $item->sequence }}</option>
  @endforeach
    <option value="{{ $items->max('sequence')   1 }}">{{ $items->max('sequence')   1 }}</option>
</select>

now I have a problem to validate request('sequence') in controller. I'm looking for some code like this

Rule::exists('items', 'sequence') OR equal => ($items->max('sequence')   1)

Note: I have a function for updating sequence when the value isn't maximum plus one.

CodePudding user response：

You can use Rule::when() to validate.

use App\Models\Item;

$max = Item::max('sequence');

Controller

$validatedData = $request->validate([
    'sequence' => ['required', 'integer', Rule::when($request->sequence != $max   1, ['exists:items,sequence'])],
]);

Or,

FormRequest

public function rules()
{
    return [
        'sequence' => ['required', 'integer', Rule::when($this->sequence != $max   1, ['exists:items,sequence'])],
    ]; 
}