public function indexAction()
 {
     if (empty(explode('/', $_SERVER['REQUEST_URI'], 4)[2])) {
         header('Location: /');
         exit;
     } else {
         $article_id = explode('/', $_SERVER['REQUEST_URI'], 4)[2];
     }
     if (ArticleModel::exists($this->pdo, $article_id)) {
         if ($_SESSION['auth']['username'] === ArticleModel::getAuthor($this->pdo, $article_id) || $_SESSION['auth']['permissions'] === 'superadmin') {
             include '../app/views/editarticle.php';
             return;
         }
     } else {
         header('Location: /404');
         exit;
     }
 }
<?php

$id = explode('/', $_SERVER['REQUEST_URI'], 4)[2];
$title = ArticleModel::getTitle($this->pdo, $id);
$date = ArticleModel::getDate($this->pdo, $id);
$author = ArticleModel::getAuthor($this->pdo, $id);
$content = ArticleModel::getContent($this->pdo, $id);
$edit_author = ArticleModel::getEditAuthor($this->pdo, $id);
$edit_date = ArticleModel::getEditDate($this->pdo, $id);
?>
<!doctype html>
<html lang="fr">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Sup'Teaching.fr | <?php 
echo $title;
?>
</title>
    <link rel="icon" href="/assets/img/favicon.png">
    <link rel="stylesheet" href="/assets/css/default.css">
    <link rel="stylesheet" href="/assets/css/jquery.sidr.dark.min.css">
    <link rel="stylesheet" href="/assets/css/styles.css">
</head>
<body>
<?php 
include 'header.php';
?>

<main role="main">
    <section class="container">