Validating array - get current iteration - laravel

Question

I'm trying to validate a POST request using Laravel's FormRequest.
The customer is submitting an order, which has an array of items. We are requiring the user to indicate whether the item needs special_delivery only if the asking_price > 500 and the quantity > 10.
The following are my intended rules:
public function rules() {
'customer_id' => 'required|integer|exists:customers,id',
'items' => 'required|array',
'items.*.name' => 'required|string',
'items.*.asking_price' => 'required|numeric',
'items.*.quantity' => 'required|numeric',
'items.*.special_delivery' // required if price > 500 && quantity > 10
}
I've attempted to do something along these lines:
Rule::requiredIf($this->input('item.*.asking_price') > 500 && $this->input('item.*.quantity' > 10));
The problem with this is that I can't find a way to access the current items iteration index to indicate which item to validate against.
I also tried the following custom validation:
function ($attribute, $value, $fail) {
preg_match('/\d+/', $attribute, $m);
$askingPrice = $this->input('items')[$m[0]]['asking_price'];
$quantity= $this->input('items')[$m[0]]['quantity'];
if ($askingPrice > 500 && $quantity > 10) {
$fail("$attribute is required");
}
}
Although this function gives me access to the current $attribute,the problem is that it will only run if special_delivery exists. Which defeats the entire purpose!
Any help will be much appreciated!
Thank you!

Answer 1

I might've come up with a solution to your problem, a index aware sometimes if you so will.
Since it's unfortunately not possible to add macros to the Validator, you would either have to override the validation factory (that's what I suggest) and use your own custom validation class or make a helper function based off the method, pass the Validator instance as an additional parameter and use this instead of $this.
Sauce first: the indexAwareSometimes validation function
function indexAwareSometimes(
\Illuminate\Contracts\Validation\Validator $validator,
string $parent,
$attribute,
$rules,
\Closure $callback
) {
foreach (Arr::get($validator->getData(), $parent) as $index => $item) {
if ($callback($validator->getData(), $index)) {
foreach ((array) $attribute as $key) {
$path = $parent.'.'.$index.'.'.$key;
$validator->addRules([$path => $rules]);
}
}
}
}
A lot of inspiration obviously came from the sometimes method and not much has changed. We're basically iterating through the array (the $parent array, in your case items) containing all our other arrays (items.*) with actual data to validate and adding the $rules (required) to $attribute (special_delivery) in the current index if $callback evaluates to true.
The callback closure requires two parameters, first being the form $data of your parent validation instance, retrieved by Validator::getData(), second the $index the outer foreach was at the time it called the callback.
In your case the usage of the function would look a little like this:
use Illuminate\Support\Arr;
class YourFormRequest extends FormRequest
{
public function rules()
{
return [
'customer_id' => 'required|integer|exists:customers,id',
'items' => 'required|array',
'items.*.name' => 'required|string',
'items.*.asking_price' => 'required|numeric',
'items.*.quantity' => 'required|numeric',
];
}
public function getValidatorInstance()
{
$validator = parent::getValidatorInstance();
indexAwareSometimes(
$validator,
'items',
'special_delivery',
'required',
fn ($data, $index) => Arr::get($data, 'items.'.$index.'.asking_price') > 500 &&
Arr::get($data, 'items.'.$index.'.quantity') > 10
);
}
}
Extending the native Validator class
Extending Laravel's native Validator class isn't as hard as it sounds. We're creating a custom ValidationServiceProvider and inherit Laravel's Illuminate\Validation\ValidationServiceProvider as a parent. Only the registerValidationFactory method needs to be replaced by a copy of it where we specify our custom Validator resolver that should be used by the factory instead:
<?php
namespace App\Providers;
use App\Validation\CustomValidator;
use Illuminate\Contracts\Translation\Translator;
use Illuminate\Validation\Factory;
use Illuminate\Validation\ValidationServiceProvider as ParentValidationServiceProvider;
class ValidationServiceProvider extends ParentValidationServiceProvider
{
protected function registerValidationFactory(): void
{
$this->app->singleton('validator', function ($app) {
$validator = new Factory($app['translator'], $app);
$resolver = function (
Translator $translator,
array $data,
array $rules,
array $messages = [],
array $customAttributes = []
) {
return new CustomValidator($translator, $data, $rules, $messages, $customAttributes);
};
$validator->resolver($resolver);
if (isset($app['db'], $app['validation.presence'])) {
$validator->setPresenceVerifier($app['validation.presence']);
}
return $validator;
});
}
}
The custom validator inherits Laravel's Illuminate\Validation\Validator and adds the indexAwareSometimes method:
<?php
namespace App\Validation;
use Closure;
use Illuminate\Support\Arr;
use Illuminate\Validation\Validator;
class CustomValidator extends Validator
{
/**
* #param string $parent
* #param string|array $attribute
* #param string|array $rules
* #param Closure $callback
*/
public function indexAwareSometimes(string $parent, $attribute, $rules, Closure $callback)
{
foreach (Arr::get($this->data, $parent) as $index => $item) {
if ($callback($this->data, $index)) {
foreach ((array) $attribute as $key) {
$path = $parent.'.'.$index.'.'.$key;
$this->addRules([$path => $rules]);
}
}
}
}
}
Then we just need to replace Laravel's Illuminate\Validation\ValidationServiceProvider with your own custom service provider in config/app.php and you're good to go.
It even works with Barry vd. Heuvel's laravel-ide-helper package.
return [
'providers' => [
//Illuminate\Validation\ValidationServiceProvider::class,
App\Providers\ValidationServiceProvider::class,
]
]
Going back to the example above, you only need to change the getValidatorInstance() method of your form request:
public function getValidatorInstance()
{
$validator = parent::getValidatorInstance();
$validator->indexAwareSometimes(
'items',
'special_delivery',
'required',
fn ($data, $index) => Arr::get($data, 'items.'.$index.'.asking_price') > 500 &&
Arr::get($data, 'items.'.$index.'.quantity') > 10
);
}