问题
My question is about Laravel validation rules.
I have two inputs a
and b
. a
is a select input with three possible values: x
, y
and z
. I want to write this rule:
b
must have a value only ifa
values isx
. Andb
must be empty otherwise.
Is there a way to write such a rule? I tried required_with
, required_without
but it seems it can not cover my case.
In other words, if the previous explanation was not clear enough:
- If
a
==x
,b
must have a value. - If
a
!=x
,b
must be empty.
回答1:
You have to create your own validation rule.
Edit app/Providers/AppServiceProvider.php
and add this validation rule to the boot
method:
// Extends the validator
\Validator::extendImplicit(
'empty_if',
function ($attribute, $value, $parameters, $validator) {
$data = request()->input($parameters[0]);
$parameters_values = array_slice($parameters, 1);
foreach ($parameters_values as $parameter_value) {
if ($data == $parameter_value && !empty($value)) {
return false;
}
}
return true;
});
// (optional) Display error replacement
\Validator::replacer(
'empty_if',
function ($message, $attribute, $rule, $parameters) {
return str_replace(
[':other', ':value'],
[$parameters[0], request()->input($parameters[0])],
$message
);
});
(optional) Create a message for error in resources/lang/en/validation.php
:
'empty_if' => 'The :attribute field must be empty when :other is :value.',
Then use this rule in a controller (with require_if
to respect both rules of the original post):
$attributes = request()->validate([
'a' => 'required',
'b' => 'required_if:a,x|empty_if:a,y,z'
]);
It works!
Side note: I will maybe create a package for this need with empty_if
and empty_unless
and post the link here
回答2:
Required if
required_if:anotherfield,value,... The field under validation must be present and not empty if the anotherfield field is equal to any value.
'b' => 'required_if:a,x'
来源:https://stackoverflow.com/questions/48420718/required-field-only-if-another-field-has-a-value-must-be-empty-otherwise