Using Query Result Count for Validation Rule (Even when empty) - php

Question

I've made a custom validation rule fiveMaxThemesChoice which consists as the name may explain it in limiting a user (Etudiant) to a maximum choice of 5 themes in the app I'm building. This is the logic below with EtudiantsChoixTheme the Eloquent where I register the choices:
<?php
namespace App\Rules;
use Illuminate\Contracts\Validation\Rule;
use App\EtudiantsChoixTheme;
class fiveMaxThemesChoice implements Rule
{
/**
* Create a new rule instance.
*
* #return void
*/
public function __construct()
{
//
}
/**
* Determine if the validation rule passes.
*
* #param string $attribute
* #param mixed $value
* #return bool
*/
public function passes($attribute, $value)
{
$choixEtudiants = EtudiantsChoixTheme::all();
foreach ($choixEtudiants as $choixEtudiant) {
$IdEtudiantOccurences = count($choixEtudiants->where('idEtudiant', auth()->user()->id));
if($IdEtudiantOccurences <= 5){
return true;
}
else{
return false;
}
}
}
/**
* Get the validation error message.
*
* #return string
*/
public function message()
{
return 'You have already chosen a maximum of 5 themes.';
}
}
When there is at least 1 record in the table, this works. The issue is that when the table get empty, the validation error message is returned even if there isn't any record yet in the table therefore not the maximum 5 (so <= 5 is supposed to be right). Why is that not working tho?
I've tried with different syntax :
$IdEtudiantOccurences = count($choixEtudiants->where('idEtudiant', auth()->user()->id)->first());
$IdEtudiantOccurences = $choixEtudiants->where('idEtudiant', auth()->user()->id)->first()->count();
$IdEtudiantOccurences = $choixEtudiants->where('idEtudiant', auth()->user()->id)->count();
The same problem persists when the table is empty. Does anyone have an idea of what can be the problem here? Any help or suggestion is welcome

Answer 1

<?php
declare(strict_types=1);
namespace App\Rules;
use Illuminate\Contracts\Validation\Rule;
use App\EtudiantsChoixTheme;
final class FiveMaxThemesChoice implements Rule
{
private const MAXIMUM_NUMBER_OF_THEMES = 5;
public function passes($attribute, $value): bool
{
$idEtudiant = auth()->user()->id;
$etudiantsQuery = EtudiantsChoixTheme::where('idEtudiant', $idEtudiant);
return $etudiantsQuery->count() <= self::MAXIMUM_NUMBER_OF_THEMES;
}
public function message(): string
{
return 'You have already chosen a maximum of 5 themes.';
}
}
Instead of fetching all (EtudiantsChoixTheme::all();) try doing the query directly and asking for the total after it (EtudiantsChoixTheme::where(...)->count())
I took this idea from the official docu: https://laravel.com/docs/4.2/queries

Answer 2

So here is your original body for passes():
public function passes($attribute, $value)
{
$choixEtudiants = EtudiantsChoixTheme::all();
foreach ($choixEtudiants as $choixEtudiant) {
$IdEtudiantOccurences = count($choixEtudiants->where('idEtudiant', auth()->user()->id));
if($IdEtudiantOccurences <= 5){
return true;
}
else{
return false;
}
}
// So what value is returned here? PHP says NULL
}
For the foreach() loop to execute, it required that the collection be larger or equal to 1. If it is empty, it won't be executed (hence neither of your explicit return statements being executed.)
public function passes($attribute, $value)
{
$choixEtudiants = EtudiantsChoixTheme::all();
foreach ($choixEtudiants as $choixEtudiant) {
$IdEtudiantOccurences = count($choixEtudiants->where('idEtudiant', auth()->user()->id));
if($IdEtudiantOccurences <= 5){
return true;
}
else{
return false;
}
}
return false ;
}
This version addresses that one lacking requirement.