Charts are empty with PHP7 and MySQL

[Darthyson]

with latest knxweb version charts are empty using php7 and mysql.

Attached is a diff-file to fix this issue using PDO in widgets/charts/retrieve.php
(Please keep in mind, that I'm completly new to php, i tried my best...)

retrieve.php.diff.txt

[knxste]

Hi friends. I'm using latest KnxWeb (2.1.1) available on github as of today (20/8/2021) on a Raspberry Pi with Raspbian. I had the same problem and I did some investigation.

First: the latest version of retrieve.php has been revised by the authors and now use mysqli_ calls, which makes Darthyson's patch obsolete

Second: I found out that, in order to make mysqli_ calls work, I had to install the package php7.3-mysql (I'm using PHP 7.3 on Raspbian), otherwise the script dies. This might be obvious, but I would have loved to find it written somewhere

Third: I found out that in retrieve.php there is an object called $mysqli to hold the connection to the database. It seems that PHP does not like it (perhaps it might be because it is identical to the mysqli class?). I modified 4 lines, substituting $mysqli with $db_conn et voilà, the graphs populate and everything works like a charm.

Now I'm enjoying this great piece of software!
Ciao
Stefano

attached the modified retrieve.php
retrieve.php.zip