Introducing Closure Stylesheets

Friday, November 11, 2011

(CSS is for programming, not for pasting)

When the Closure Tools were first released a little over two years ago, they gave web developers the ability to organize and optimize their JavaScript and HTML in a new way. But there was something missing, namely, a tool to help manage CSS.

You see, the nature of CSS runs contrary to the DRY principle that is exhibited in good software engineering. For example, if there is a color that should be used for multiple classes in a stylesheet, a developer has no choice but to copy-and-paste it everywhere because CSS has no concept of variables. Similarly, if there is a value in a stylesheet that is derived from other values, there is no way to express that because CSS also lacks functions. Common patterns of style blocks are duplicated over and over because CSS has no macros. All of these properties of CSS conspire to make stylesheets extremely difficult to maintain.

To this end, we are excited to introduce the missing piece in the Closure Tools suite: Closure Stylesheets. Closure Stylesheets is an an extension to CSS that adds variables, functions, conditionals, and mixins to standard CSS. The tool also supports minification, linting, RTL flipping, and CSS class renaming. As the existing Closure Tools have done for JavaScript and HTML, Closure Stylesheets will help you write CSS in a maintainable way, while also empowering you to deliver optimized code to your users. We hope you enjoy it! Please let us know what you think in the discussion forum.

By Michael Bolin, Open Source Engineer