Site Crash on Install

[repairfox]

I installed via extension manager, and it crashed my wiki. I deleted the /lib/plugin/explain folder, wiki was restored. I then installed manually, and got the same results.

Here is the error on trying to access my wiki:
TypeError: count(): Argument #1 ($value) must be of type Countable|array, null given
An unforeseen error has occured. This is most likely a bug somewhere. It might be a problem in the explain plugin.
More info has been written to the DokuWiki error log.

Here is my error log:
2022-08-20.log

In /conf/explain.conf I have:
Carpe Diem <TAB> Latin for "pluck the day". <TAB> Introduction:Definitions#Carpe_Diem <TAB> http://en.wikipedia.org/wiki/carpe_diem

I'm using PHP 8.1
Any Ideas?

[jorbig]

I can confirm the problem, and it only occurs using PHP 8, not with 7.

The specific error is caused by line 93. Change if (count($this->map) === 0) to if (count((array)$this->map) === 0)

Now the pages load fine, but the keywords aren't picked up... Maybe @splitbrain can help us out to make this plugin PHP 8 proof?

[jorbig]

I was able to fix this, with the help of ChatGPT:

To make the code compatible with PHP 8, you need to make the following changes:

Replace the function constructor syntax_plugin_explain() with the __construct() function.
The constructor function with the same name as the class is deprecated since PHP 7.
__construct() function is used in PHP 8 as the constructor function.

[dunron]

Nice find! Thank you!