willy.club/app/WillySoft/ErrorHandler.php

<?php

namespace WillySoft;

abstract class ErrorHandler
{
    /**
     * On error or exception erase the output buffer and hand the
     * error message as an HTML formatted string to the callback
     * then die
     */
    static function register(callable $callback)
    {
        ob_start();

        set_error_handler(function($errno, $errstr, $errfile, $errline) use (&$callback) {
            error_log("Error[$errno]: $errstr in $errfile at line $errline\n");
            $errstr = htmlspecialchars($errstr);
            self::oof($callback, "<b>Error[$errno]:</b> $errstr in <b>$errfile</b> at line <b>$errline</b>");
        });

        set_exception_handler(function($exception) use (&$callback) {
            error_log("Uncaught Exception: $exception\n");
            self::oof($callback, "<b>Uncaught Exception:</b> {$exception}");
        });
    }

    private static function oof(callable $callback, string $error_message)
    {
        ob_end_clean();

        http_response_code(500);
        header_remove();

        $callback($error_message);
        die();
    }
}