support for PHP8

[laurent-martin]

I upgraded ubuntu to 21.10 : patatras, knxweb stops working

PHP Fatal error: Uncaught SmartyException: Unable to load template file 'design_view.tpl'

resolution turns out to be very simple: the constructor of MySmarty in include/tpl.php still uses the old style constructor name.

fixed like this:

...
	public function __construct()
	{
		parent::__construct();
		global $_config;
...

Now, all good again.

Although not necessary probably , I installed the latest version of smarty like this:
1- installed "composer" : apt install composer
2- created file: composer.json

{
    "require": {
        "smarty/smarty": "*"
    }
}

then executed composer install

3- changed paths in include/tpl.php

[knxste]

I confirm that, in order for Knxweb2 to work with PHP 8.4 (the latest version to date), Martin's change to include/tpl.php is required. Also, the version of smarty included in Knxweb2 does not work anymore with PHP 8.4, and it must be replaced with smarty 4.5.5 (latest version of smarty 4). This solves the issue for the time being.
The changes introduced in smarty 5 (latest version to date is 5.5.0) break knxweb2 more extensively and require more work, which might be required in the future as newer versions of PHP will come out that may possibly be not supported by smarty 4.5.5.
May I suggest to release an updated version of knxweb2 with the described changes to support PHP 8.4, so to make work easier for those upgrading their OS to Debian bookworm (for example).

[spyou42]

I'm working on a (pretty much vibecoded) complete rewrite of the PHP backend in Python. Don't think i will have time to publish it but if anyone is hot enough or needs it, i'd be happy to share.