premailer now honours specificity

21 March 2013   0 comments   Python

Mind That Age!

This blog post is 4 years old! Most likely, its content is outdated. Especially if it's technical.

Powered by Fusion×

Thanks to Theo Spears awesome effort premailer now support CSS specificity. What that means is that when linked and inline CSS blocks are transformed into tag style attributes the order is preserved as you'd expect.

When the browser applies CSS to elements it does it in a specific order. For example if you have this CSS:

p.tag { color: blue; }
p { color: red; }

and this HTML:

<p>Regular text</p>
<p class="tag">Special text</p>

the browser knows to draw the first paragraph tag in red and the second paragraph in red. It does that because p.tag is more specific that p.

Before, it would just blindly take each selector and set it as a style tag like this:

<p style="color:red">Regular text</p>
<p style="color:blue; color:red" class="tag">Special text</p>

which is not what you want.

The code in action is here.

Thanks Theo!


Thank you for posting a comment

Your email will never ever be published

Related posts

HTML whitespace "compression" - don't bother! 11 March 2013
Never put external Javascript in the <head> 02 April 2013
Premailer 3.0.0 - classes kept by default 07 June 2016 08 July 2015
premailer 2.9.0 and new rules for `base_url` 11 May 2015
Premailer on Python 3 08 October 2014
premailer now with 100% test coverage 22 August 2014
COPYFILE_DISABLE and python distutils in python 2.6 12 April 2014
premailer now excludes pseudo selectors by default 27 May 2013
How to use premailer as a command line script 13 July 2012 - Transform CSS into line style attributes with lxml.html 11 July 2009