ldc-jeusselin/app/Rules/Cotationsxml.php

<?php

namespace App\Rules;

use Illuminate\Contracts\Validation\Rule;

class Cotationsxml implements Rule
{
    private $schema_errors = "Le fichier n'est pas conforme au schéma XSD : ";

    /**
     * Create a new rule instance.
     *
     * @return void
     */
    public function __construct()
    {
    }

    /**
     * Determine if the validation rule passes.
     *
     * @param  string $attribute
     * @param  mixed  $value
     * @return boolean
     */
    public function passes($attribute, $value)
    {
        // file is stored, now validate the schema
        $xsd         = storage_path('app/cotations/Jeusselin.xsd');
        $domDocument = new \DOMDocument();
        $domDocument->load($value->path());
        // Enable user error handling
        libxml_use_internal_errors(true);
        if (!$domDocument->schemaValidate($xsd)) {
            $errors = libxml_get_errors();
            foreach ($errors as $error) {
                $this->schema_errors .= $error->message;
            }
            libxml_clear_errors();
            return false;
        } else {
            return true;
        }
    }

    /**
     * Get the validation error message.
     *
     * @return string
     */
    public function message()
    {
        return $this->schema_errors;
    }
}