@import and @media is passed to cssselect's parse_simple_selector, causing errors about premailer

[mxdubois]

Looks like this could be related to #15

Did that pull request get unmerged somehow?

[peterbe]

Hi @mxdubois !

Yeah, premailer isn't as smart as the css parser in a web browser for example.
What do you think the right thing is to do here? It could recognize it with a simple regex and then do a urllib.urlopen(url).read() and include that.

[peterbe]

Regarding #15 I think that got merged. It's here: https://github.com/peterbe/premailer/blob/master/premailer/premailer.py#L129

[mxdubois]

Well @SimonSapin recommended using tinycss:

Consider using an actual CSS parser like tinycss. With tinycss you can test if some_rule.at_keyword is None: … to only pick style rules (as opposed to at-rules such as @import.)

He didn't seem to approve of using regex to parse CSS. He linked me to this and said it applies to CSS as well.

I was thinking it'd be good just to ignore the @import so that it doesn't break cssselect. But if you want to take on the challenge of importing it, that could be neat. I'm not sure if you'd be able to inline an @font-face definition though.

[peterbe]

I'll be honest... @SimonSapin is right. Doing a regex is cheating that will eventually fail. But I feel like there's lots more things that can go wrong if you expect premailer to be as smart as a web browser.

I don't think I will set aside time to work on a solution that uses tinycss or urllib.urlopen to import those external dependencies.

But if there's a nice patch with tests I'd be very eager to look at it. :)

[guneysus]

And giving <style type="text/css" media="all"> only strip classes but not generates inline styles.
Removing media="all" works as expected. <style type="text/css" >