Using Flexbox in web applications

Over last few months, I discovered the joy that is CSS Flexbox, which solves the “how do I lay out this set of div’s in horizontally or vertically”. I’ve used it in three projects so far:

• Centering the timer interface in my meditation app, so that it scales nicely from a 320×480 FirefoxOS device all the way up to a high definition monitor
• Laying out the chart / sidebar elements in the Eideticker dashboard so that maximum horizontal space is used
• Fixing various problems in the Treeherder UI on smaller screens (see bug 1043474 and its dependent bugs)

When I talk to people about their troubles with CSS, layout comes up really high on the list. Historically, basic layout problems like a panel of vertical buttons have been ridiculously difficult, involving hacks involving floating divs and absolute positioning or JavaScript layout libraries. This is why people write articles entitled “Give up and use tables”.

Flexbox has pretty much put an end to these problems for me. There’s no longer any need to “give up and use tables” because using flexbox is pretty much just *like* using tables for layout, just with more uniform and predictable behaviour. They’re so great. I think we’re pretty close to Flexbox being supported across all the major browsers, so it’s fair to start using them for custom web applications where compatibility with (e.g.) IE8 is not an issue.

To try and spread the word, I wrote up a howto article on using flexbox for web applications on MDN, covering some of the common use cases I mention above. If you’ve been curious about flexbox but unsure how to use it, please have a look.