jQuery UI 1.9 Milestone 4 – Accordion Redesign

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The fourth milestone release for jQuery UI 1.9 is out, featuring the updated Accordion widget. This release also includes updates and bug fixes to existing and new widgets that will not make it into a 1.8.x release.

What’s a Milestone Release?

A milestone release makes it easier to try out the latest development code of jQuery UI without necessarily having to check out code from GitHub.

With a milestone release you can try out new widgets that are pretty far along (though not yet final) and provide feedback based on released code with a specific version number.

Note: the API is subject to change as the code is still under active development.


The Accordion API has been redesigned for simplicity, extensibility and consistency with other widgets in jQuery UI. We’d love to get feedback on any compatibility issues you may have with existing code. Everything supported in 1.8 should work out-of-the-box in 1.9; if something breaks, we will work to fix it before the final release.


As mentioned above, 1.9 will support the 1.8 API, as well as the redesigned API. However, this introduces two problems. First, some of the APIs don’t overlap cleanly. For example, in 1.8 you can collapse an accordion by setting the active option to false or -1; but with the API updates, you can set the active option to a negative number in order to activate a panel starting from the last panel instead of the first (similar to .eq()). Second, while both APIs are supported, it’s hard to test whether you’ve successfully updated all of your code for compatibility with the 2.0 release which will not support the 1.8 API. In order to deal with these issues, we’ve introduced a flag, jQuery.uiBackCompat, which can be used to prevent the backward compatibility layer from executing. This flag must be set after jQuery is loaded, but before jQuery UI is loaded. Toggling the flag after jQuery UI has been loaded will have no effect.


You can download the jQuery UI 1.9 Milestone 4 – Accordion Redesign release as a zip file or via git:

File Downloads


How to Provide Feedback

wiki page

To help with the testing of the Accordion redesign, visit the Accordion page on our Development & Planning wiki.


If the comments section on the wiki page doesn’t provide enough room for your feedback, post to the Developing jQuery UI Forum and tag the post:

How to Contribute Code

If you have code changes for the Accordion, fork jQuery UI on GitHub and submit a pull request.

If you’re new to git or GitHub, see our guide: How to submit a fix to jQuery UI – The Easy Way.


Note: please do NOT use the comments section of this blog post for feedback on the Accordion widget. This discussion should occur on the wiki page and the forum (see How to Provide Feedback, above).

If you have feedback on us doing our fourth milestone release, feel free to leave a comment below. Thank you.

5 thoughts on “jQuery UI 1.9 Milestone 4 – Accordion Redesign

  1. @JQuery Team

    Any chance of redesigning/refactoring the Slider widget.

    It’s the only UI widget that requires every UI Core (Core, Mouse, Widget, Position) element just to function.

  2. @Jacob – Slider doesn’t require Position. It does require Core and Widget, but so do all other jQuery UI interactions and widgets. What makes it unique (among widgets today) is that it depends on mouse, but duplicating that same code into slider would not make it any smaller, and would make the whole library larger.

  3. Stacey on said:

    While I’m elated about everything coming in 1.9, is it sad that I’m the most excited about the simple Tooltip plugin as a default part of the jQuery UI?