Miscellaneous Developer Updates in 5.2

New wp_body_open Theme Hook

5.2 will introduce a new wp_body_open() function that is used to trigger a wp_body_open action. This action is intended to allow developers to inject code immediately following the opening <body> tagtag A directory in Subversion. WordPress uses tags to store a single snapshot of a version (3.6, 3.6.1, etc.), the common convention of tags in version control systems. (Not to be confused with post tags.).

Themes are encouraged to begin using this hook as soon as 5.2 is released. The function should be placed just inside the opening <body> tag of the template file. For example:

<body <?php body_class(); ?>>
<?php wp_body_open(); ?>

Usage of this hook should be reserved for output of unseen elements like <script> tags or additional metadata. It should not be used to add arbitrary HTMLHTML HyperText Markup Language. The semantic scripting language primarily used for outputting content in web browsers. content to a page that could break layouts or lead to unexpected situations.

Backward Compatibility

In order to support previous versions of WordPress, it is recommended you use a shim in your theme to prevent fatal errors from the undefined function.

if ( ! function_exists( 'wp_body_open' ) ) {
    function wp_body_open() {
        do_action( 'wp_body_open' );
    }
}

Note that if your theme is going to be submitted to the theme repository, then you won’t be able to use the wp_ prefix, as it will get flagged by the Theme Check. An alternative is to call do_action directly where the wp_body_open() function is placed in the first example, like this:

<body <?php body_class(); ?>>
<?php 
if ( function_exists( 'wp_body_open' ) ) {
    wp_body_open();
} else {
    do_action( 'wp_body_open' );
}

Plugins can detect the use of this function in a theme by calling did_action( 'wp_body_open' ) and falling back to alternative methods if the action has not fired.

See #12563 and #46679 for more information.

Login HeaderHeader The header of your site is typically the first thing people will experience. The masthead or header art located across the top of your page is part of the look and feel of your website. It can influence a visitor’s opinion about your content and you/ your organization’s brand. It may also look different on different screen sizes. Adjustments

The <h1> on wp-login.php previously used the title attribute inconsistently between multisitemultisite Used to describe a WordPress installation with a network of multiple blogs, grouped by sites. This installation type has shared users tables, and creates separate database tables for each blog (wp_posts becomes wp_0_posts). See also network, blog, site and single site. In multisite, the value of this attribute was the title of the networknetwork (versus site, blog), but on a single site, it merely duplicated the link text. As part of #24766, many of the title attributes throughout coreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress. have been removed, as they are often redundant or useless.

In WordPress 5.2, this title attribute has been removed and its associated filterFilter Filters are one of the two types of Hooks https://codex.wordpress.org/Plugin_API/Hooks. They provide a way for functions to modify data of other functions. They are the counterpart to Actions. Unlike Actions, filters are meant to work in an isolated manner, and should never have side effects such as affecting global variables and output., login_headertitle, has been deprecated. If the deprecated filter is used, it now applies to the link text. A new login_headertext filter has been added in its place.

In addition to the <h1> changes, the link on the WordPress logo now always points to WordPress.orgWordPress.org The community site where WordPress code is created and shared by the users. This is where you can download the source code for WordPress core, plugins and themes as well as the central location for community conversations and organization. https://wordpress.org/ by default. In prior versions, it would point to the primary site of the network on multisite. This URLURL A specific web address of a website or web page on the Internet, such as a website’s URL www.wordpress.org can still be filtered using login_headerurl.

See: #42537

Editor Image Caption Styles

In the blockBlock Block is the abstract term used to describe units of markup that, composed together, form the content or layout of a webpage using the WordPress editor. The idea combines concepts of what in the past may have achieved with shortcodes, custom HTML, and embed discovery into a single consistent API and user experience. editor, the font-size and color attributes were removed from the figcaption element unless the active theme has opted into default block styles.

Additionally, a margin: 0; attribute applied to .block-editor-rich-text__editable was removed from the RichText component, so as to allow theme styles to control those margins without high specificity. If your pluginPlugin A plugin is a piece of software containing a group of functions that can be added to a WordPress website. They can extend functionality or add new features to your WordPress websites. WordPress plugins are written in the PHP programming language and integrate seamlessly with WordPress. These can be free in the WordPress.org Plugin Directory https://wordpress.org/plugins/ or can be cost-based plugin from a third-party relied on this margin, you’ll need to add this back to the necessary elements.

See: wordpress/gutenberg/pull/14366

Walker_Category HTML Attributes

A new category_list_link_attributes filter has been added to Walker_Category to allow customization of the HTML attributes applied to a categoryCategory The 'category' taxonomy lets you group posts / content together that share a common bond. Categories are pre-defined and broad ranging. list item’s anchor element.

This complements the page_menu_link_attributes filter in Walker_Page and the nav_menu_link_attributes filter in Walker_Nav_Menu.

See #40666

New Additional Content Filter on User Delete Action

When users are deleted from a site, WordPress checks to confirm that they do not have posts or links assigned to them. However, there are cases where a plugin may have content associated with them outside of a post_author or link_owner relationship.

WordPress 5.2 introduces a new users_have_additional_content filter, which allows plugins to run additional checks for custom content relationships.

Note: This filter specifically doesn’t override the system users_have_content checks to avoid any undesired suppression of the reassign functionality. Instead it enables the ability to flag that a user has additional content.

Developers should note that this filter doesn’t conduct the reassignment operations on the data, this will be done by the delete_user or deleted_user actions which provide the ID of the user as well as the ID of the user for reassignment if selected.

Using the Filter

Below is a simple example of how a plugin could use the filter along with the delete_user action to allow the re-assignment of non-standard content.

First the filter returns true to signify that users have additional content. This triggers the content reassignment UIUI User interface to appear in the adminadmin (and super admin) for all users being deleted.

It then uses the delete_user action hook to reassign additional content at the same time as any standard core content.

function myplugin_users_have_additional_content( $has_content, $user_ids ) {
	if ( ! $has_content ) {
		// Check if any of the the users being deleted have additional content
		if ( myplugin_check_users_have_content( $user_ids ) ) {
			return true;
		}
	}
	return $has_content;
}
add_filter( ‘users_have_additional_content’, ‘myplugin_users_have_additional_content’, 10, 2 );

function myplugin_reassign_user_content( $deleted_user, $reassigned_user ) {
	if ( $reassigned_user ) {
		// Re-assign the content from the deleted user
		myplugin_reassign_coauthor( $deleted_user, $reassigned_user );
	}
}
add_action( ‘delete_user’, ‘myplugin_reassign_user_content’, 10, 2 );

See: #36860

Other Updates of Note:

As part of the 2019 focus of improving automatic updates, the sodium_compat library will now be included in WordPress. Sodium Compat is a polyfill for the Sodium cryptography library for PHPPHP The web scripting language in which WordPress is primarily architected. WordPress requires PHP 5.6.20 or higher versions <7.2. Including this will facilitate security enhancements, with the initial focus of enabling more secure signing and verification of update packages. See: #45806
Twemoji is now updated to version 12.0.1. See: #46805
Fixed a bugbug A bug is an error or unexpected result. Performance improvements, code optimization, and are considered enhancements, not defects. After feature freeze, only bugs are dealt with, with regressions (adverse changes from the previous version) being the highest priority. where an Allow header was not being returned for OPTIONS requests to the REST APIREST API The REST API is an acronym for the RESTful Application Program Interface (API) that uses HTTP requests to GET, PUT, POST and DELETE data. It is how the front end of an application (think “phone app” or “website”) can communicate with the data store (think “database” or “file system”) https://developer.wordpress.org/rest-api/.. See: #45753
A $domain parameter has been added to translate_user_role(). This will allow translations of custom user roles added in plugins. See: #38736

#5-2, #dev-notes, #editor, #themes

Michael Nelson 11:47 pm on April 24, 2019

Thanks for the update! I’m especially happy about the sodium_compat work moving forward. 👏
Tran Ngoc Tuan Anh 1:35 am on April 25, 2019
I think wp_body_open is a bad name. The hook doesn’t fit the context where the body tagtag A directory in Subversion. WordPress uses tags to store a single snapshot of a version (3.6, 3.6.1, etc.), the common convention of tags in version control systems. (Not to be confused with post tags.) opens. It happens when the body tag already opened. We can tell in another way: we don’t know that hook fires before or after the tag is opened by just looking into its name.

I’d suggest following name convention in the Theme Hook Alliance, where it suggests:
- HooksHooks In WordPress theme and development, hooks are functions that can be applied to an action or a Filter in WordPress. Actions are functions performed when a certain event occurs in WordPress. Filters allow you to modify certain functions. Arguments used to hook both filters and actions look the same. immediately preceding a blockBlock Block is the abstract term used to describe units of markup that, composed together, form the content or layout of a webpage using the WordPress editor. The idea combines concepts of what in the past may have achieved with shortcodes, custom HTML, and embed discovery into a single consistent API and user experience. should use _before.
- Hooks immediately following a block should use _after.
- Hooks placed at the very beginning of a block should use _top.
- Hooks placed at the very end of a block should use _bottom.
In this case, the hook should be `wp_body_top`.

I created a TracTrac An open source project by Edgewall Software that serves as a bug tracker and project management tool for WordPress. ticketticket Created for both bug reports and feature development on the bug tracker. for this:

https://core.trac.wordpress.org/ticket/47032#ticket
Joy 2:16 pm on April 25, 2019

Please don’t recommend that themes include a shim function named with a wp prefix. Any themes for the WordPress repository doing that will be caught in Theme Check, as the function prefix must be the theme’s prefix.
The if statement and do_action is the way to go.
- William Earnhardt 2:23 pm on April 25, 2019
  
  Thanks Joy. I’ve updated the note to clarify that.
- apedog 11:48 am on April 30, 2019
  
  Theif function_exists/else do_action is some real ugly shim to have in theme template files. I’d even go as far as suggesting adding an exception to the Theme Check just for wp_body_open (pass the ugliness somewhere else – less conspicuous). The wp_body_open is a really elegant solution that got cumbersome really fast. Still happy to have it tho.
Rami Yushuvaev 8:33 pm on April 25, 2019

Few weeks ago I wrote a post about the new `wp_body_open()` function and the `wp_body_open` action:

https://generatewp.com/wordpress-5-2-action-that-every-theme-should-use/
yllipylla 12:42 pm on May 8, 2019
wpza 8:52 pm on May 20, 2019

Good stuff, we also wrote a wp_body_open() guide too; demonstrating how it can also be paired with body_class().
Saiful Islam 7:03 am on July 23, 2019

Very effective function. It will help to reduce code.