Proof that PHP works well without any framework.

BasicPHPFramework.php

<?php

function redirect(string $url)
{
    header("Location: $url");
    die();
}

function json(array $arr)
{
    die(json_encode($arr));
}

function text($text)
{
    die($text);
}

class BasicPHPFramework
{
    /**
     * Flash messages session key name.
     *
     * @var string
     */
    private string $FLASH = 'FLASH_MESSAGES';

    /**
     * @var array
     */
    private array $PAGES = [];

    /**
     * @var array
     */
    private array $MIDS = [];

    /**
     * @var array
     */
    private array $CONFIG = [];

    /**
     * PDO object.
     *
     * @var PDO
     */
    public PDO $pdo;

    /**
     * Router URL matches.
     *
     * @var array
     */
    public array $matches;

    /**
     * HTTP status codes helper.
     *
     * @var array
     */
    public array $httpStatusCodes = [100 => "Continue", 101 => "Switching Protocols", 102 => "Processing", 200 => "OK", 201 => "Created", 202 => "Accepted", 203 => "Non-Authoritative Information", 204 => "No Content", 205 => "Reset Content", 206 => "Partial Content", 207 => "Multi-Status", 300 => "Multiple Choices", 301 => "Moved Permanently", 302 => "Found", 303 => "See Other", 304 => "Not Modified", 305 => "Use Proxy", 306 => "(Unused)", 307 => "Temporary Redirect", 308 => "Permanent Redirect", 400 => "Bad Request", 401 => "Unauthorized", 402 => "Payment Required", 403 => "Forbidden", 404 => "Not Found", 405 => "Method Not Allowed", 406 => "Not Acceptable", 407 => "Proxy Authentication Required", 408 => "Request Timeout", 409 => "Conflict", 410 => "Gone", 411 => "Length Required", 412 => "Precondition Failed", 413 => "Request Entity Too Large", 414 => "Request-URI Too Long", 415 => "Unsupported Media Type", 416 => "Requested Range Not Satisfiable", 417 => "Expectation Failed", 418 => "I'm a teapot", 419 => "Authentication Timeout", 420 => "Enhance Your Calm", 422 => "Unprocessable Entity", 423 => "Locked", 424 => "Failed Dependency", 424 => "Method Failure", 425 => "Unordered Collection", 426 => "Upgrade Required", 428 => "Precondition Required", 429 => "Too Many Requests", 431 => "Request Header Fields Too Large", 444 => "No Response", 449 => "Retry With", 450 => "Blocked by Windows Parental Controls", 451 => "Unavailable For Legal Reasons", 494 => "Request Header Too Large", 495 => "Cert Error", 496 => "No Cert", 497 => "HTTP to HTTPS", 499 => "Client Closed Request", 500 => "Internal Server Error", 501 => "Not Implemented", 502 => "Bad Gateway", 503 => "Service Unavailable", 504 => "Gateway Timeout", 505 => "HTTP Version Not Supported", 506 => "Variant Also Negotiates", 507 => "Insufficient Storage", 508 => "Loop Detected", 509 => "Bandwidth Limit Exceeded", 510 => "Not Extended", 511 => "Network Authentication Required", 598 => "Network read timeout error", 599 => "Network connect timeout error"];

    /**
     * BasicPHPFramework constructor. Set the config here.
     *
     * @param array $config The config array.
     * 
     *    $config = [
     *       'db' => [(string) DSN, (string) Username, (string) Password],
     *       'assets_folder' => string,
     *    ];
     */

    public function __construct($config = [])
    {
        $this->CONFIG = $config;
        if (!empty($config["db"])) {
            $this->pdo = new PDO($config["db"][0], $config["db"][1], $config["db"][2]);
        }

        if (!empty($config["assets_folder"])) {
            $assets = $config["assets_folder"];
            $this->addPage("GET_ASSETS", "/assets/(.*)", function (self $fw) use ($assets) {
                $filename = $assets . "/" . $fw->matches[1];

                if (!is_file($filename)) {
                    return $this->callHttpResponse(404);
                }

                header('Content-Type: ' . $this->mimeContentType($filename));
                readfile($filename);
                die();
            });
        }

        if (empty($config["view"])) {
            $config["view"] = "pages";
        }
    }

    /**
     * Add an middleware to the framework.
     *
     * @param Closure $function
     * @return BasicPHPFramework
     */
    public function add(Closure $function): self
    {
        $this->MIDS[] = [
            $function
        ];

        return $this;
    }

    /**
     * Add a page to the framework.
     *
     * @param string $method
     * @param string $route
     * @param Closure $function
     * @return BasicPHPFramework
     */
    public function addPage($method, $url, Closure $function): self
    {
        if (is_array($method) && is_array($url)) {
            foreach ($method as $m) {
                foreach ($url as $u) {
                    $this->addPage($m, $u, $function);
                }
            }
            return $this;
        }

        if (is_array($method)) {
            foreach ($method as $m) {
                $this->addPage($m, $url, $function);
            }
            return $this;
        }

        if (is_array($url)) {
            foreach ($url as $u) {
                $this->addPage($method, $u, $function);
            }
            return $this;
        }

        $this->PAGES[] = [
            $method,
            $url,
            $function
        ];

        return $this;
    }

    /**
     * Run the Framework.
     *
     * @return void
     */
    public function run()
    {
        $status_code = 404;
        $url = $_SERVER['REQUEST_URI'];

        foreach ($this->PAGES as $page) {
            if (!empty($_GET) && strstr($url, "?")) {
                $url = strstr($url, "?", true);
            }

            if (!preg_match("/^" . (str_replace("/", "\/", $page[1])) . "$/m", $url, $matches)) {
                continue;
            }

            $this->matches = $matches;

            if (!in_array(strtoupper($page[0]), ["*", "GET_ASSETS"]) && $_SERVER['REQUEST_METHOD'] !== strtoupper($page[0])) {
                $status_code = 405;
                continue;
            }

            $status_code = 200;
            break;
        }

        if ($status_code === 200 && $page[0] === "GET_ASSETS") {
            return call_user_func($page[2], $this);
        }

        foreach ($this->MIDS as $mid) {
            call_user_func($mid[0], $this, [$status_code, $page]);
        }

        if ($status_code === 200) {
            return call_user_func($page[2], $this);
        }

        return $this->callHttpResponse($status_code);
    }

    /**
     * Call the HTTP Response.
     *
     * @param int $status_code
     * @return never
     */
    public function callHttpResponse($code = 404)
    {
        if (!empty($this->CONFIG["status_codes"][$code])) {
            call_user_func($this->CONFIG["status_codes"][$code], $this);
        } else if (array_key_exists($code, $this->httpStatusCodes)) {
            http_response_code($code);
            die("<html><head><title>" . $code . " " . $this->httpStatusCodes[$code] . "</title></head><body><h1>" . $code . "</h1><h2>" . $this->httpStatusCodes[$code] . "</h2></body></html>");
        } else {
            http_response_code(500);
            die("<html><head><title>500 Internal Server Error</title></head><body><h1>500</h1><br><h2>Internal Server Error -- BasicPHPFramework error</h2></body></html>");
        }
    }

    /**
     * Get the MIME Content Type.
     *
     * @param string $filename
     * @return string
     */
    function mimeContentType($filename)
    {
        $mime_types = [
            'txt' => 'text/plain',
            'htm' => 'text/html',
            'html' => 'text/html',
            'php' => 'text/html',
            'css' => 'text/css',
            'js' => 'application/javascript',
            'json' => 'application/json',
            'xml' => 'application/xml',
            'swf' => 'application/x-shockwave-flash',
            'flv' => 'video/x-flv',
            'png' => 'image/png',
            'jpe' => 'image/jpeg',
            'jpeg' => 'image/jpeg',
            'jpg' => 'image/jpeg',
            'gif' => 'image/gif',
            'bmp' => 'image/bmp',
            'ico' => 'image/vnd.microsoft.icon',
            'tiff' => 'image/tiff',
            'tif' => 'image/tiff',
            'svg' => 'image/svg+xml',
            'svgz' => 'image/svg+xml',
            'zip' => 'application/zip',
            'rar' => 'application/x-rar-compressed',
            'exe' => 'application/x-msdownload',
            'msi' => 'application/x-msdownload',
            'cab' => 'application/vnd.ms-cab-compressed',
            'mp3' => 'audio/mpeg',
            'qt' => 'video/quicktime',
            'mov' => 'video/quicktime',
            'pdf' => 'application/pdf',
            'psd' => 'image/vnd.adobe.photoshop',
            'ai' => 'application/postscript',
            'eps' => 'application/postscript',
            'ps' => 'application/postscript',
            'doc' => 'application/msword',
            'rtf' => 'application/rtf',
            'xls' => 'application/vnd.ms-excel',
            'ppt' => 'application/vnd.ms-powerpoint',
            'odt' => 'application/vnd.oasis.opendocument.text',
            'ods' => 'application/vnd.oasis.opendocument.spreadsheet',
        ];

        $ext = pathinfo($filename, PATHINFO_EXTENSION);

        if (array_key_exists($ext, $mime_types)) {
            return $mime_types[$ext];
        } elseif (function_exists('finfo_open')) {
            $finfo = finfo_open(FILEINFO_MIME);
            $mimetype = finfo_file($finfo, $filename);
            finfo_close($finfo);
            return $mimetype;
        } elseif (function_exists('mime_content_type')) {
            return mime_content_type($filename);
        } else {
            return 'application/octet-stream';
        }
    }

    /**
     * Create or get one|all flash messages.
     *
     * @param string $name
     * @param string $message
     * @param string $type
     * @return void
     */
    public function flash(string $name = '', string $message = '', string $type = '')
    {
        if ($name !== '' && $message !== '' && $type !== '') {
            if (isset($_SESSION[$this->FLASH][$name])) {
                unset($_SESSION[$this->FLASH][$name]);
            }
            $_SESSION[$this->FLASH][$name] = ['message' => $message, 'type' => $type];
            return true;
        } elseif ($name !== '' && $message === '' && $type === '') {
            if (!isset($_SESSION[$this->FLASH][$name])) {
                return false;
            }
            $msg = $_SESSION[$this->FLASH][$name];
            unset($_SESSION[$this->FLASH][$name]);

            return $msg;
        } elseif ($name === '' && $message === '' && $type === '') {
            if (!isset($_SESSION[$this->FLASH])) {
                return false;
            }
            $msg = $_SESSION[$this->FLASH];
            unset($_SESSION[$this->FLASH]);

            return $msg;
        }
    }

    /**
     * Check array is associative.
     *
     * @param array $arr
     * @return boolean
     */
    public static function isAssoc(array $arr)
    {
        if (array() === $arr) return false;
        return array_keys($arr) !== range(0, count($arr) - 1);
    }

    /**
     * Run query and return results.
     *
     * @param string $query
     * @param array $params
     * @return (PDOStatement|bool)[]
     */
    public function query(string $query, array $params = []): array
    {
        if (empty($this->CONFIG["db"])) {
            throw new Exception("No DB connection found. Please set a DB connection in the config array.");
        }

        $stmt = $this->pdo->prepare($query);

        if (empty($params)) {
            $exec = $stmt->execute();
        } else if (self::isAssoc($params)) {
            foreach ($params as $key => $value) {
                $stmt->bindValue(($key[0] == ":" ? "" : ":") . $key, $value);
            }
            $exec = $stmt->execute();
        } else {
            $exec = $stmt->execute($params);
        }

        return [$stmt, $exec];
    }

    /**
     * Return fetch all results.
     *
     * @param string $query
     * @param array $params
     * @return array
     */
    public function fetchAll(string $query, array $params = []): array
    {
        if (empty($this->CONFIG["db"])) {
            throw new Exception("No DB connection found. Please set a DB connection in the config array.");
        }

        [$stmt, $exec] = $this->query($query, $params);
        return $stmt->fetchAll(PDO::FETCH_ASSOC);
    }

    /**
     * Return fetch one result.
     *
     * @param string $query
     * @param array $params
     * @return array
     */
    public function fetch(string $query, array $params = [])
    {
        if (empty($this->CONFIG["db"])) {
            throw new Exception("No DB connection found. Please set a DB connection in the config array.");
        }

        [$stmt, $exec] = $this->query($query, $params);
        return $stmt->fetch(PDO::FETCH_ASSOC);
    }

    /**
     * Get row count of query.
     *
     * @param string $query
     * @param array $params
     * @return int
     */
    public function rowCount(string $query, array $params = []): int
    {
        if (empty($this->CONFIG["db"])) {
            throw new Exception("No DB connection found. Please set a DB connection in the config array.");
        }

        [$stmt, $exec] = $this->query($query, $params);
        return $stmt->rowCount();
    }

    public function view($file, $data = [])
    {
        $output = "";
        $file = __DIR__ . "/" . $this->CONFIG["view"] . "/" . $file . ".php";

        if (file_exists($file)) {
            extract($data);
            ob_start();
            include($file);
            $output = ob_get_clean();
        } else {
            return $this->callHttpResponse(404);
        }

        echo ($output);
        die;
    }
}

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