Re: Validating media queries in Java

Henri Sivonen wrote:
> I'm trying to validate CSS Media Queries as HTML5 attribute values. I'm 
> using Java.
> I first thought that media queries would be syntactically very 
> simple--something for which importing the W3C CSS Validator or a parser 
> generator as a project dependency would be and overkill. I have since 
> learned that most of the complications are hiding inside <value> and the 
> language is nowhere near as simple as the pseudo-BNF in the Media 
> Queries spec makes it appear. In particular, even traditional CSS 
> lengths make the states in the parser balloon and support for calc() 
> would make things much, much more complex.
> I'm now considering abandoning my hand-rolled code in favor of either a 
> customized generated parser or a generic CSS parser that someone has 
> already written. I checked out the W3C CSS Validator source today. 
> Unfortunately, it seems that it doesn't have an entry point for parsing 
> media queries in isolation and the JavaCC grammar it uses is tightly 
> coupled with the program internals.
> I'd appreciate advice:
> Is there some Open Source work that I'm missing but could use? Other 
> recommendations on how to proceed?

We could disallow calc() in media queries. I don't see much of a use case
for it.


Received on Friday, 16 November 2007 17:02:43 UTC