We had an RFC meeting today about an RFC (https://www.mediawiki.org/wiki/Requests_for_comment/Watch_Categorylinks) regarding watching categorization changes.

The original proposal was to use Echo. However, there were some concerns regarding that, regarding performance and UX (this seems more consistent with the watchlist's UX).

The decision at the end was to use the recentchanges table. There are two many remaining design questions:

1. Should categorization changes (on pages using the template) due to a template change be ignored? This would simplify implementation, but limit the usefulness of the feature.

If template changes are reflected, there were some suggestions on implementation.

One was to create a single bulk event when the template is edited. The problem with this is the template can have different effects on different pages using it.

So it would somehow need to keep track of the effects, and create an RC entry (with the relevant info either in, or pointed to by, rc_params) at the end of the template processing.

Gabriel Wicke suggested an alternate approach that might be easier: Point from the RC entry to an ID, and keep updating the list of pages affected by that categorization batch as it progresses. It could maybe use the revid of the template/underlying page change as this ID.

2. Whether to allow watching only the category page (i.e. the description of the category), or require watching both that and categorization/decategorization together. If the latter, filtering (e.g. "ignore categorization/decategorization" view) could be done on the watchlist page.

The RFC will be updated.

Matt Flaschen