Last modified: 2011-12-14 17:37:24 UTC
When a page is rendered from various sources, such as: * the page itself, * local images, * foreign repository images, * transcluded templates, * other pages transcluded, * pages transcluded from other wikis, * transcluded special pages, * etc. we currently only can address a specific version for the page source. For anything else, the current version at the time of page rendering is taken, but we do not send their actual version information anywhere. The latter should be changed. We do show templates already at edit pages in preview, a similar list could be included in rendered pages metadata or comments, along with an "oldid". This would make saved renderd content more valuable because with the version information, possible conflicts, errors or bugs were easier to trace and could be attributed to specific versions. If I am right with the assumption that the youngest oldid in a list would sufficiently determine all others, we had a pretty simple way to refer to historic versions of pages as they appeared to a certain point in time. Otherwise, all oldids were necessary but still, knowing them would allow us to refer to historic pages as they once were without having to accept newer versions of templates or images. We could even mix - render a page from history, but with a broken image fixed, and so on. At least being able to show previous versions of pages as they really were at their time is imho a goal of quite some value, and will likely be asked for increasingly often as Wikis become more pervalent in ones everydays life.
see also bug 850
see also bug 4677
I'm not sure how saving all these details would help with showing old pages as they were (unless we also save the rendered dependant documents, in which case we might as well just keep the final rendered page at each version, either way it'd be impractical to save the complete rendered documents of all these pages). If you have a specific date in mind, you can look up what the relevant images/templates/etc at that time were (well maybe not for transcluded special pages, [scary] interwiki transclusions, and foreign images are iffy, but the other things on your list you can)
