New in WordPress 3.4: Theme Customizer

Much of the focus of the upcoming WordPress 3.4 release involves Themes and the Appearance Settings user interface. In addition to some under-the-hood improvements to handling of custom header images and custom backgrounds, WordPress 3.4 includes some improvements that will be readily apparent to end users.

One such improvement is the Theme Customizer, which is invoked whenever the user activates a new Theme:

The WordPress 3.4 Theme Customizer, which allows the user to apply - and to live-preview, Theme customizations

As you can see, the Theme Customizer includes a live preview, allowing the user to try out customizations before applying them to the Theme.

The Theme customizer panel expanded

The left panel includes all of the available customizations. This list should look familiar; it is comprised of several of the existing customizations, including:

• Site Title and Tagline (Dashboard -> Settings General)
• Header (Dashboard -> Appearance -> Header)
• Background (Dashboard -> Appearance -> Background)
• Navigation (Dashboard -> Appearance -> Menus)
• Static Front Page (Dashboard -> Settings -> Reading)

When expanded, each customization section includes simplified versions of the full settings pages corresponding to the setting. (The original settings pages are still available, and can still be found in their original locations as noted above, should you need or want the full UI for each setting.)

Perhaps the best feature of the Theme Customizer, however, is the live preview. Make a change in the left-hand panel, and that change is displayed in the preview.

Here’s the header image customized. Select the image in the panel, and it is displayed:

Select an image in the customization panel, and the change is reflected in the live previewer

Here’s the navigation menu customized. Apply an (existing) custom menu to a Theme location, and it is displayed:

Apply a custom navigation menu to a Theme location, and it is displayed in the live preview

And here are the front page settings customized; live preview of a static front page or blog posts index:

Change front page display to a static page or blog posts index, and the live preview is updated

So what do you think? Will you find this new Theme customizer feature to be useful? If you’d like to test-drive it for yourself, just install the latest WordPress 3.4 pre-release version, using the WordPress Beta Tester Plugin (the normal caveats regarding pre-release software in production environments apply, of course).