使用数据透视表进行Laravel请求验证

Question

I have a model Paper. Paper can have different sizes and colors but sizes only relate to some colors and so on. I have a pivot table set up where sizes correspond to colors. I'm using form request validation and I have models with belongsToMany relationships set up for sizes and colors. When I do Paper:create I want to send an error if a color and size are a mismatch based on that pivot table. Is there a built-in "Laravel way" of achieving this or should I just loop through the pivot table when color and size are set?

Answer 1

The most "Laravely" way that I can think of, is using the form request class like so:

<?php

namespace App\Http\Requests;

use App\Http\Requests\Request;

class PaperFormRequest extends Request
{
    public function authorize()
    {
        return true;
    }

    public function rules()
    {
        // rules here
    }

    protected function getValidatorInstance()
    {
        $validator = parent::getValidatorInstance();

        $validator->after(function() use ($validator) {


            // logic for detecting mismatches goes here


            // To add validation-errors, simply do:
            $validator->errors()->add(
                'colorMistmatch',
                'This color does not go with this paper'
            );

            return $validator;
        }
    }
}

Once errors have been added to the validator-instance, you can display them in your blade-views by doing this:

@if ($errors->has('colorMistmach'))
   {{ $errors->first('colorMistmach') }}
@endif