Last modified: 2014-07-15 18:05:55 UTC
On Wikimedia Commons, files are tracked for maintenance or internal purposes using hidden categories. MultimediaViewer appears to display the first three categories based on the alphabetical order. This results in displaying non-topical categories which do not make much sense. To give a few examples: * FPs by creator/place/subject on https://www.mediawiki.org/wiki/Lightbox_demo#mediaviewer/File:Thyssen-Krupp-Quartier-Essen-Q1-2013.jpg * License category on <https://www.mediawiki.org/wiki/Lightbox_demo#mediaviewer/File:British%20Museum%20Great%20Court,%20London,%20UK%20-%20Diliff.jpg> * Maintenance category on <https://www.mediawiki.org/wiki/Lightbox_demo#mediaviewer/File:Glenfinnan%20Site.jpg> The Gallerypreview Gadget (an older, similar attempt to enhance navigation) was working through this through a blacklist [1]. I think ignoring hidden categories is the quickest and safest way. [1] https://commons.wikimedia.org/wiki/MediaWiki:Gadget-Gallerypreview.js
More to the point, I and other s believe all visible Commons categories should be displayed in the viewer. There have been many comments to this effect at the MultimediaViewer discussion page.
This is partly caused by the implementation of getForeignCategories, added in git commit 4893d1f of Bug 56598. I see it's handy to pass along a TitleArray, but this implementation really quite deviates from getCategories in OutputPage, and looses the 'hidden' flag https://doc.wikimedia.org/mediawiki-core/master/php/html/OutputPage_8php_source.html#l01240 We should really figure out a better more permanent path forward there... Any ideas ?
The return value from getForeignCategories() is analogous to getCategories() except that get it returns Title objects while getCategories() just returns the title strings (I don't remember if there was any real reason for the difference or it just seemed cleaner). The hidden flags are returned by OutputPage::getCategoryLinks(). I guess we could add WikiFilePage::getForeignCategoryData() which returns hidden flags as well.
