Laravel 验证：仅需要且只有一个字段

Question

I have got two fields namely number and percentage. I want a user to input value in only one input field. If a user inputs values in both number and percentage field, the system should throw validation error. Is there anything we can do with laravel validation to achieve this?

Thanks.

Answer 1

You can write a custom validator for that: http://laravel.com/docs/5.0/validation#custom-validation-rules

It may looks somthing like this:

class CustomValidator extends Illuminate\Validation\Validator {

    public function validateEmpty($attribute, $value)
    {
        return ! $this->validateRequired($attribute, $value);
    }

    public function validateEmptyIf($attribute, $value, $parameters)
    {
        $key = $parameters[0];

        if ($this->validateRequired($key, $this->getValue($key))) {
            return $this->validateEmpty($attribute, $value);
        }

        return true;
    }
}

Register it in a service provider:

Validator::resolver(function($translator, $data, $rules, $messages, $attributes)
{
    return new CustomValidator($translator, $data, $rules, $messages, $attributes);
});

Use it (in a form request, for example):

class StoreSomethingRequest extends FormRequest {
    // ...

    public function rules()
    {
        return [
            'percentage' => 'empty_if:number',
            'number'     => 'empty_if:percentage',
        ];
    }
}

Update Just tested it in Tinker:

Validator::make(['foo' => 'foo', 'bar' => 'bar'], ['bar' => 'empty_if:foo'])->fails()
=> true
Validator::make(['foo' => '', 'bar' => 'bar'], ['bar' => 'empty_if:foo'])->fails()
=> false
Validator::make(['foo' => '', 'bar' => 'bar'], ['foo' => 'empty_if:bar'])->fails()
=> false

Answer 2

this can be a good solution as well:

return [
    'video' => [
        'bail',
        function ($attribute, $value, $fail) {
            if (request()->has($attribute) === request()->filled('videourl')) {
                return $fail('Only 1 of the two is allowed');
            }
        },
        'file',
    ],
   'videourl' => [
        'bail',
        function ($attribute, $value, $fail) {
            if (request()->has($attribute) === request()->filled('video')) {
                return $fail('Only 1 of the two is allowed');
            }
        },
    ]