New Developer Features in Opera 11.50 Beta

This morning, we’ve released Opera 11.50 beta through our Next channel, and it comes with a number of interesting developer bits. Let’s have a look.

classList goodness

Using classList, you can easily add, remove, or toggle a class on an element, without the need for complex regex or libraries. The code to toggle a class is as simple as this:


You can then attach some styles to #blinds.cover, and off you go. It even works nicely with CSS transitions, so you can create smooth page effects that are applied on the click of a button. For a simple example, see my classList demo.

<time> element

We’re the first browser to support the <time> element. Mike has covered how you can make use of it in a previous post. Also be sure to check out our time robot demo.

Session History & Navigation

Presto 2.8 also comes with support for HTML5 Session History & Navigation. You can find all details on our specs pages.


Support for data-* attributes and dataset has been around since Opera 11.10, but Divya has now written a nice dataset developer introduction on Dev.Opera.

Speed Dial extensions

And last but not least, we’ve further enhanced our Speed Dial extensions implementation. You can download the latest Speed Dial extensions from our extensions catalog, or build your own using our Speed Dial Extension developer introduction, which is now available not only in English, but also in German, Simplified Chinese, Russian, Bahasa Indonesia, Spanish, Vietnamese, Brazilian Portuguese and Japanese. In the video below, Arnstein explains how easy it is to build one.

Note: due to a caching issue, Opera Dragonfly stops working from time to time. In order to resolve this and continue debugging, clear up your cache and refresh. Of course, we’re working on a fix for this, so this should only be a temporary annoyance.