Laravel 10：请求无places字段时仍需验证该字段的实现方法

验证规则代码片段 #

'places' => [
    new CompanyHasPlacesRule,
],

验证类代码 #

public function validate(string $attribute, mixed $value, Closure $fail): void
{
    $company = DB::table('companies')
        ->select('companies.id', DB::raw('GROUP_CONCAT(places.id) as placeIDs'))
        ->join('places', 'companies.id', '=', 'places.company_id')
        ->where('companies.id', $this->data['company_id'])
        ->groupBy('companies.id')
        ->first();
    
    if (! $company?->placeIDs && $value === null) {
        return;
    }

    if ($company?->placeIDs && $value === null) {
        $fail('Please select place associated with the company.');
    }

    if ($value && $company->placeIDs) {

        $difference = array_diff($value, explode(',', $company->placeIDs));

        if (! empty($difference)) {
            $fail('Selected company does not have this place assigned.');
        }

        return;
    }

    $fail('Selected company does not have this place assigned.');

}

问题描述 #

公司并非总会关联场所，但如果公司有场所，则必须选择一个或多个places字段；而判断公司是否有场所的逻辑在验证规则内部。请问如何实现即使请求中不存在places字段，仍对该字段执行验证？

解决方案 #

Laravel 默认不会对请求中不存在的字段执行验证规则，要强制触发验证，只需按以下步骤处理：

1. 添加present验证规则
   修改验证规则定义，为places字段添加present规则。这个规则会确保无论请求中是否包含该字段，都会触发后续的自定义验证逻辑，此时字段值会被设为null：

   'places' => [
       'present',
       new CompanyHasPlacesRule,
   ],
   

2. 优化验证类逻辑（可选）
   你的现有逻辑已经能处理$value === null的场景，但可以合并冗余分支，让代码更简洁：

   public function validate(string $attribute, mixed $value, Closure $fail): void
   {
       $company = DB::table('companies')
           ->select('companies.id', DB::raw('GROUP_CONCAT(places.id) as placeIDs'))
           ->join('places', 'companies.id', '=', 'places.company_id')
           ->where('companies.id', $this->data['company_id'])
           ->groupBy('companies.id')
           ->first();
       
       $hasPlaces = !empty($company?->placeIDs);
       
       // 公司无关联场所，直接通过验证
       if (!$hasPlaces) {
           return;
       }
       
       // 公司有场所但未选择任何地点
       if ($value === null || (is_array($value) && empty($value))) {
           $fail('Please select place associated with the company.');
       }
       
       // 校验所选地点是否属于该公司
       $allowedPlaces = explode(',', $company->placeIDs);
       $difference = array_diff((array)$value, $allowedPlaces);
       
       if (!empty($difference)) {
           $fail('Selected company does not have this place assigned.');
       }
   }
   

内容的提问来源于stack exchange，提问作者Sasha