Tag Archives: oocss

CSS Wish List

Don’t get me wrong, I think CSS is awesome. It is a great way of defining the UI, but it could be even better. I’m excited about the special effects, transitions, and graphic elements currently being added to the CSS specification. They will help us write faster pages by eliminating the need for UI graphics for things like rounded corners. On the other hand, we also need to add structure to the language to make it easier for designers and developers to author new pages and applications. I hope the CSS Working Group will consider my suggestions.

  • Make CSS a better declarative language
  • Abstract repeating patterns in the code
  • Do not make CSS a programming language

Suggestions for the CSS Working Group

The community has been talking about some form of constants or variables in different incarnations for almost a decade, it is time to make this a reality. While it is possible to duplicate this functionality with a preprocessor (an excellent stop gap until browser support catches up), ultimately this is a tool which should live within the CSS itself. It is a powerful way of expressing more about the objects we are building.

The mixins and prototypes (and associated includes and extends properties) are designed to allow document authors to abstract reusable bits of code and better manage and maintain their style sheets. The goal is to mimic the effect of using multiple class names in the HTML without the drawbacks associated with current implementations. Authors need extends and include in order to write faster, smaller, more efficient style sheets.

CSS is a powerful expressive language. It needs certain modifications so that it will be robust, maintainable, and easy to implement.

From JSConf.eu

How did this begin?

At some point, I realized I was coding CSS with a bunch of “rules” and best practices that weren’t the currently accepted norm. I found myself writing comments to try to express these rules like:

/* ----- faq (extends mod) ----- */


/* margin top = bottom height - corner height */

At that point I realized that I was trying to express via comments something which was missing from existing CSS syntax. I looked at other proposals and my own work building web sites for the last 9 years (eek! almost a decade). I first cataloged many of the rules because, at this point, they were mostly intuition and I needed to figure out why I do things the way I do.

When that had stabilized, I began to explore a syntax for this new language of declarative objects. Trying to balance standard programming practices with a desire that the syntax fit well with document authors expectations for how the language works.

CSS Inheritance Today

It is currently possible to implement CSS inheritance in three ways, however, each has its drawbacks.

  1. Multiple class names, clog the HTML with classes that have the same semantic value (just more or less abstract). They introduce an unnecessary dependency because CSS inheritance is defined in the HTML.
  2. By chaining comma delimited selector strings, authors lose the ability to group related rules into discrete blocks of code. The quantity of code increases dramatically. A preprocessor could make option #2 more feasible, but abstracting a necessary part of the language into another layer isn’t a permanent solution. As well, the resulting CSS is not human readable, this step should take place in the document tree.
  3. With a JavaScript parser, the heavy lifting could be done on the client-side, however this would likely have a negative performance impact particularly on older browsers and slower machines.

A Concrete Example – Based on YUI Standard Module Format

I found myself writing the following code:

/* weatherModule (extends .mod) */
.weatherModule .hd{...}
.weatherModule .ft{...}
.weatherModule .bd{...}

The html looked like this:

<div class="mod weatherMod">
  <div class="hd">Local Weather for SF</div>
  <div class="bd">Cloudy with 100% chance of rain, and fog.</div>
  <div class="ft"><a href="newLoc.html">Change your location?</a></div>

I was using multiple class names (which is great because ultimately it reduces the footprint of the CSS file by an order of magnitude), but it would be better if the browser could understand my intention, and process any instance of weatherModule as if it was also a mod.

<div class="weatherMod"> 
<!-- Can the browser treat this as an instance of mod? -->
  <div class="hd">Local Weather for SF</div>
  <div class="bd">Cloudy with 100% chance of rain, and fog.</div>
  <div class="ft"><a href="newLoc.html">Change your location?</a></div>

Thanks so much to the following people who gave invaluable advice, feedback, and (in some cases) tolerated an enormous number of iterations. Nothing gets created in a vacuum and dissenting opinions were as helpful as supporters. :) William Cook, David Federman, Gopal Vijayaraghavan, Douglas Crockford, Stoyan Stefanov, Ryan Grove, Marcel Laverdet, Eric Meyer, Dan Cederholm, Ethan Marcotte, Jeffrey Zeldman, Gonzalo Cordero, Jenny Han Donnelly, Chris Klaiber, Tantek Çelik, Jeremy Keith, Wendy Chisholm, Aaron Gustafson, Fred Sauer, Dave Hyatt, Eric Schurman, Brad Neuberg, John Allsopp, Tom Hughes-Croucher, Chris Mills, Nicholas C. Zakas, Peter-Paul Koch, Doug Schepers, Amy Hoy, Kyle Simpson, Brian LeRoux, Chris Blizzard, Philippe Le Hegaret and (of course) Daniel Glazman.

Object Oriented CSS video on YDN

Yahoo! Developer Network has released a video of my Object Oriented CSS talk at Web Directions North just in time for Ada Lovelace day. I’ve also been included in a feature on Women in Technology. I’m absolutely flattered to be included among these fantastic technical women. Wow.

Object Oriented CSS: for high performance websites and web applications.

Find out more about object oriented css

  1. Open source project on github (GIT is having some DNS issues, be patient)
  2. Follow along with the slides on slideshare
  3. Join the OOCSS google group

Thanks to Havi, Julie, Ricky, Yahoo! Developer Network, and the whole Web Directions North team for their hard work putting this together!