It was bothering me that all the wikis I tried, all had either errors, feature lacks, too many dependencies or were simply unmaintained. So I decided to create yet another one. Curiously, the third hit when googling 'django wiki' is Create a wiki in 20 minutes. Luckily that's not really true, so all the PHP guys and MediaWiki can continue breathing. This took me several days.
Hierarchy and relations
First of all, as in the Trac wiki system, I chose to create a system for hierarchy, meaning that it's possible to create an article and then create sub-articles. The hierarchy does not support multiple inheritance, because it needs to be basis for the permission system. That's where the relation system comes in place: All articles can contain symmetrical relations to any other articles in the hierarchy.
Python and Django supports Markdown pretty much out of the box, so it's an obvious choice to use this for parsing. The HTML features of normal Markdown have been removed, so all HTML is escaped in django-simple-wiki. And parsing is static, so every time a revision is created, the contents are passed and stored. This means that the contents of the article itself are not supposed to be dynamic. On the other hand, it is desirable to avoid parsing contents for every page hit. The parsing area of the application is only a few lines of code, and can be expanded if further parsing needs to be done, or someone wants to replace Markdown completely. For instance, if no parsing is done and HTML escaping is disabled, the wiki becomes a very simple CMS.
There are a few out standing problems:
Permission system is related to User entries in the Django auth system. But maybe this is too much of an annoyance, if the project already has groups setup in the existing auth system. On the other hand, other users would be bothered to setup both wiki groups and user groups, if the permission system was linked to user groups. And directly linking articles to user groups would require wiki-related groups to be created directly in the auth system.
Since relations are symmetrical, what should happen if one article is locked, but a user modifies it's relations by deleting them from related articles?
Title editing: The title can only be created once, since it is coupled to the 'slug' of the article. A user can deliberately create a completely different title, which is fine, but should subsequent editing be allowed, which would add complexity to the revision system?
Article deletion: When an article is deleted from the backend it shouldn't worry anyone. But if the feature is added to the frontend, we would want to handle maliciousness etc. But should we really store all these files and revisions? Should we alert admins, so they can do the final cleanup?