WordPress 4.4: Field Guide

WordPress 4.4 is the next major release of WordPress and is shaping up to be an amazing release. While you have likely discovered many of the changes from testing your plugins, themes, and sites (you have been testing, right?), this post highlights some of the exciting 🎉changes developers can look forward to. 💥

Externally Embeddable

https://make.wordpress.org/core/2015/10/28/new-embeds-feature-in-wordpress-4-4/

Using a handful of filters, you can customize how your site looks when it’s embedded elsewhere. As a part of the work around embeds, there are also a couple of new functions for retrieving and displaying embeddable content. The post above also links to a plugin which will remove the ability to embed your site elsewhere.

REST API Infrastructure Introduction

The infrastructure to create a REST API has landed in WordPress core.  Adding your own endpoints (or using the latest version of the REST API plugin) is now even easier.  The new embed feature mentioned above uses this new infrastructure.
Note: If you are using v1 of the API plugin, it is incompatible with 4.4, however an update is planned before 4.4 ships. The update will not use the new REST API infrastructure, so you’ll want to update your REST API usage eventually. If you are using v2 of the API plugin, be sure you’re on beta 5 or later; previous versions do not support WordPress 4.4.

Responsive Image Insertion

Through the use of a display filter, image tags in WordPress now include srcset and sizes.  These two attributes to the <img> tag allow browsers to choose the most appropriate image size and download it, ignoring the others. This can save bandwidth and speed up page load times. There are new functions, filters, and an additional default image size available to help with the creation of responsive images.

wp_title Deprecation Decision

Since WordPress 4.1, add_theme_support( 'title-tag' ); has been the recommended way of outputing a title tag for themes.  Now, a year later the wp_title function has been officially deprecated. Take a look at this post if you want to see all the great new filters you can use to modify title tags.

UPDATE 12 November – wp_title has been reinstated for the time being. It is a zombie function.  add_theme_support( 'title-tag' ); remains the recommended way to insert a title tag into your theme, however there were use cases for wp_title that were not accounted for in the original deprecation decison

Term Taxonomy Tranquility

WordPress 4.4 is the latest in a string of releases to feature major updates to the taxonomy system. This release introduces of term meta, a new WP_Term class, and a host of other under the hood changes.

Comment Component Cultivation

https://make.wordpress.org/core/2015/10/28/comment-object-and-query-features-in-4-4/

https://make.wordpress.org/core/2015/09/25/changes-to-fields-output-by-comment_form-in-wordpress-4-4/

Comments received love both on the front end of sites and on the backend. On the front-end, the comment field will always appear first, before the name and email fields. This fixes a longstanding bug where the behavior was different for logged in and logged out users.

Under the hood, comments are now represented by a WP_Comment class and comment queries are now considerably more powerful.

Multisite Momentum

Like taxonomy and comments, the multisite features gains a new class, WP_Network. Additionally, there are now *_network_option functions which make it easier to use multiple networks. The linked post also highlights new hooks, some notable bug fixes, and two newly-deprecated functions. If you use WordPress in a multisite environment, this is a must-read.

Heading Hierarchy Happiness

Headings on the admin screens are now more semantic. Be sure to update your custom admin screens to follow the proper heading structure. These changes help users of assistive technologies, such as screen readers.

Twenty Sixteen

Each year, WordPress releases a new default theme and this year is no exception. Twenty Sixteen is a brand new theme, bundled with WordPress 4.4. Default themes are incredibly popular; be sure to test your plugins to ensure they function well with Twenty Sixteen.

Other Notes

So far, this release has had over two thousand commits. There are many additional changes not outlined above including: the removal of support for my-hacks.php(Update Nov 20th: My Hacks support was added back), giving add_rewrite_rule support for an easier-to-read syntax, support for single-{post_type}-{post_name} in the template hierarchy, pretty permalinks for unattached media, and stronger enforcement of the show_ui argument in custom post types. As with every major update, it is very important to test every feature in your plugins and themes to ensure there are no regressions in their behavior.

Closing

If you haven’t been testing your themes, plugins, and sites with WordPress 4.4, now is a great time to start. You can grab a copy from svn (or git), download the nightly builds, or install it using the Beta Tester Plugin.

WordPress 4.4 is not recommended for use on production servers until the final release has been announced on the WordPress News blog. The release is currently targeted for December 8, 2015. Get testing today!

#4-4, #dev-notes, #field-guide