Laravel：验证需要大于另一个的整数字段

发布于08月17日

我有两个字段，只有当两个字段都不存在时才是可选的:

$rules = [
  'initial_page' => 'required_with:end_page|integer|min:1|digits_between: 1,5',
  'end_page' => 'required_with:initial_page|integer|min:2|digits_between:1,5'
];

Now, end_page needs to be greater than initial_page. How include this filter?

推荐答案

有no built-in validation个字段可以让你比较像Laravel中那样的字段值，所以你需要实现custom validator，这将让你在需要的地方重用验证.幸运的是，Laravel编写了自定义验证器really easy.

从定义YOR AppServiceProvider中的新验证器开始:

class AppServiceProvider extends ServiceProvider
{
  public function boot()
  {
    Validator::extend('greater_than_field', function($attribute, $value, $parameters, $validator) {
      $min_field = $parameters[0];
      $data = $validator->getData();
      $min_value = $data[$min_field];
      return $value > $min_value;
    });   

    Validator::replacer('greater_than_field', function($message, $attribute, $rule, $parameters) {
      return str_replace(':field', $parameters[0], $message);
    });
  }
}

Now you can use your brand new validation rule in your $rules:

$rules = [
  'initial_page' => 'required_with:end_page|integer|min:1|digits_between: 1,5',
  'end_page' => 'required_with:initial_page|integer|greater_than_field:initial_page|digits_between:1,5'
];

You'll find more info about creating custom validators here: http://laravel.com/docs/5.1/validation#custom-validation-rules. They are easy to define and can then be used everywhere you validate your data.