19/07/2014
The CSS3 multi-column module
The W3C multi-column module is a CSS level-three working draft, proposed by the W3C to extend the current CSS box model. The module’s intent is to allow content to flow into multiple columns inside an element. It offers new CSS properties that let the designers specify in how many columns an element should be rendered. The browser takes care of formatting the text so that the columns are balanced.
diagram contracting the single-column CSS box model with a CSS3 two-column layouts
The proposed new CSS properties are:
‘column-count’, to determine the number of columns into which the content of the element will flow.
‘column-width’, to describe the optimal width of each column.
‘column-gap’, to set the padding between columns.
‘column-rule’, to define a border between columns.
You can learn more about these, and some other new properties in the W3C working draft.
Multi-column implementations
While the draft was published in 2001, it is still far from being a final recommendation, let alone implemented. Or is it?
IMPLEMENTATIONS IN THE BROWSER
The developers working on Gecko 1.8 (Mozilla & Co.) announced the first native implementation of the module in April this year, and the recent release of the Firefox 1.5 beta (based on Gecko 1.8) does indeed support parts of the CSS3 Multi-Column module.
We can only hope that more browser developers will follow.
SCRIPTING IMPLEMENTATIONS
Other ingenious web developers have silently worked their way around the limitations of the CSS box model for quite some time. The International Herald Tribune, for instance, is using a JavaScript-driven multi-column layout for its news articles. Michael van Ouwerkerk, back in 2002, wrote a JavaScript that splits the content of an element and rearranges it into several columns. (Doubtless others have used similar approaches.)
One can certainly do wonderful things with JavaScript (and the document object model), and reworking markup to achieve a multi-column layout happens to be one of them.
With this in mind, let’s take a closer look at those new CSS3 properties from the W3C specification:
Column-count: That’s how many times a JavaScript needs to split content into left floating elements.
Column-width: That’s the width of each newly created element.
Column-gap: That’s a left (or right) padding for these elements.
Column-rule: That’s a left (or right) border.
Since such JavaScript would process the page after it is rendered, every factor that used to be a problem, font-size, images on/off, is already taken care of. Also, if JavaScript is not available, the layout would not be altered (in other words, it would degrade nicely).
An interim measure for experimentation
Since it can be done, and since I wouldn’t be writing this article if I had nothing to show for it, here it is: a (mostly) cross-browser JavaScript implementation of the CSS3 multi-column module. (View example.)
The implementation is an unobtrusive, stand-alone piece of code that acts as a JavaScript parser for this CSS3 extension. You don’t need any knowledge of JavaScript to use it, just upload the file to your site and link it to your page:
You can then start using the CSS3 properties in your stylesheets as you would do for any other CSS.
Cautions
There are some limitations though that you need to understand. First, the browser-based CSS parser is designed to ignore properties that it does not support. To circumvent this, this implementation relies on a relatively simple parser written in JavaScript. This parser cannot handle complex constructions, like cascading rules spread across different selectors. Keep it simple. This following styles, for example, would be acceptable:
article {
column-count: 2;
column-gap: 20px;
}
Also in Issue № 204
CSS Swag: Multi-Column Lists
by Paul Novitski
Secondly, the JavaScript cuts and moves content from one column to another. There are naturally a number of elements that cannot or should not be divided up: images for instance, but also tables, headings, etc. The algorithm tries to accommodate these content types, but can break or yield unexpected results in some circumstances. You are welcome to report any problem with the rendered layout and we’ll try to improve it as we go.
Browsers
The script has been tested in IE6, Firefox 1.0.4, Netscape 7.1, Safari 1.2 and 2.0, and Opera 8 (though the Opera tests indicate a tendency to crash).
