Module talk:Check for unknown parameters - Wikipedia

On Module:Check_for_unknown_parameters#L-94, please replace the undefined variable preview with preview_text. That expression is always going to evaluate to true and so will never reach the third expression. Awesome Aasim 17:57, 29 August 2024 (UTC)Reply

Done. Also added require ('strict') which will catch other globals. Keep an eye on Category:Pages with script errors to see if the addition reveals other globals.

—Trappist the monk (talk) 18:08, 29 August 2024 (UTC)Reply

We are using this module on Module:WikiProject banner. We first check if Category:Pages using WikiProject PROJECT with unknown parameters exists and if not, then we use Category:WikiProject templates with unknown parameters instead. The problem is that this is causing thousands of links to non-existent categories to be recorded, which can be seen in Special:WantedPages. My suggestion is as follows. The module can accept an additional argument called fallback which is a category which will be used if the one specified in unknown does not exist. In this way we can check existence of that category only when unknown parameters are discovered, not in every single case. — Martin (MSGJ · talk) 14:19, 4 September 2024 (UTC)Reply

What is it that I'm missing? If the problem is caused by something that happens in Module:WikiProject banner, that is where the fix should be applied. Adding miscellaneous one-off patches to this module is not a good idea. When you switch to the default category, you know that the preferred category does not exist so why link to it? Link to the preferred category only when it exists.

—Trappist the monk (talk) 15:35, 4 September 2024 (UTC)Reply

I'll try and explain better. Or you can look at the code at around Module:WikiProject banner#L-831. We have to check existence before calling this module. Checking existence adds a link to the page. Therefore every transclusion of {{WikiProject Lepidoptera}} is generating a link to Category:Pages using WikiProject Lepidoptera with unknown parameters which is not so good. I would prefer to only check if the category exists if there are some unknown parameters. That check can only happen in this module. Or perhaps you have a better idea — Martin (MSGJ · talk) 21:02, 4 September 2024 (UTC)Reply

I haven't taken any real time to study the code (it has taken me more time to write this than I spent looking at the code) but Module:Check for unknown parameters line 113 appears to return a concatenated string of unknown parameters (apparently without delimiters). If there are no unknowns then the table.concat(res) returns an empty string. So, it looks like p._check(args, pargs) returns:

nil when either of args and pargs is not a table

empty string when there are no unknown parameters

some sort of list of unknown parameters

If this is true then you should be checking the returned value from require('Module:Check for unknown parameters')._check(parameters, parent_args) before you fiddle about with categories.

—Trappist the monk (talk) 22:22, 4 September 2024 (UTC)Reply

Great, thanks. I'll look into that — Martin (MSGJ · talk) 08:55, 5 September 2024 (UTC)Reply

Yes that works. Unfortunately it means that I need to call the module twice: the second time after deciding which category to use. But this will only happen if there are any unknown parameters so will not affect performance unduly. — Martin (MSGJ · talk) 09:06, 5 September 2024 (UTC)Reply

Add comments to your code. When you are crushed by a steamroller while jaywalking Main Street, whoever comes after you to maintain that module can then know why you did what you did.

—Trappist the monk (talk) 11:48, 5 September 2024 (UTC)Reply