The reason we have ResourceLoader deployed and working today is because we avoided re-inventing the wheel as much as possible. There are many assumptions in this RFC that I think are incorrect. Upon reading it, these arguments appear to be tailored towards supporting a specific idea of inventing a new CSS processor, rather than trying to solve existing problems (see hashar's comment).
- CSSJanus does not need to be a part of a CSS preprocessor - it can stand on it's own just fine
- CSSMin, which does the URL remapping and embedding, could/should be extended to support local wiki files, this need not be built into a CSS preprocessor
- Any CSS preprocessor we choose to support can be run before CSSJanus and CSSMin, there's no problem here at all
- Existing CSS preprocessors do add new syntax, but that syntax is based on existing CSS syntax and in the case of LessCSS and SASS (ever since they changed their syntax to match LessCSS) is very well thought out
- Wikia is already using SASS, so we should talk to them about the pros/cons from their actual experience instead of hypothesizing about what the pros/cons may be
It's my recomendation that we do the following:
- Add local wiki image support to CSSMin using a generic extension mechanism so that CSSMin can remain a stand-alone library
- Evaluate using SASS and talk more with developers at Wikia who have experience implementing this into MediaWiki and porting skin code to it
This post was posted by Trevor Parscal (WMF), but signed as Trevor Parscal.