Miscellaneous block editor API additions in WordPress 5.8

WordPress 5.8 brings several additions and tweaks to 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 APIAPI An API or Application Programming Interface is a software intermediary that allows programs to interact with each other and share data in limited, clearly defined ways..

Contextual patterns for easier creation and block transformations

We’ve all been there. Staring at a blank page sometimes with an idea of what you want to create; often with a mind as blank as the page. To make the creation process easier, there is now a way to suggest patterns based on the block being used. This is now implemented for the Query block and includes some coreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress. patterns to start with.

In addition, there is an API to suggest pattern transformations that are contextual to the currently selected blocks. So how this is different to the patterns current behaviour? Previously, patterns insert demo content that must be updated after insertion. With this feature, it’s possible to use some patterns and retain existing attributes or content.

So it’s for existing blocks!

An important thing to note here is that a pattern transform can result to adding more blocks than the ones currently selected. You can see this with an example like the below where we have a Quote block but the pattern consist of more blocks:

This is the first iteration of the feature that covers most simple blocks (without innerBlocks). A new experimental API has been created where we can mark what block attributes count as content attributes. You can see more details in the PR.

In the long run as this work continues and spreads to more blocks, it will be easier to create content and get inspired without leaving the editor.

Pattern Registration API

if you’re creating your own custom block patterns, there’s a new blockTypes property that will allow your patterns to show up in other contexts like the transform menu. blockTypes property is an array containing the block names.

/register_block_pattern(
     'heading-example',
     array(
         'title'         => __( 'Black heading' ),
         'categories'    => array( 'text' ),
         'blockTypes'    => array( 'core/heading' ),
         'viewportWidth' => 500,
         'content'       => ' <!-- wp:heading {"level":3,"backgroundColor":"black","textColor":"white"} -->
    <h3 class="has-white-color has-black-background-color has-text-color has-background">Demo heading</h3>
<!-- /wp:heading -->',
     )
 );

To learn more about block patterns, see this WordPress News article: So you want to make block patterns.

BlockControls group prop

In WordPress 5.8, core blocks toolbars have been updated and made more consistent across blocks by splitting them into 4 areas like shown in the following screenshot.

To do so a new group prop has been added to the wp.blockEditor.BlockControls component. Third-party block authors are encourage to use this prop in their block code to follow the core blocks design pattern.

<BlockControls group="block">
    <ToolbarButton onClick={ doSomething }>{ __( 'My button' ) }</ToolbarButton>
</BlockControls>

#5-8, #core-editor, #dev-notes

Block-styles loading enhancements in WordPress 5.8

WordPress 5.8 improves the way we load 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.-styles by introducing 2 new features:

  • Load styles only for rendered blocks in a page
  • Inline small styles

Only load styles for used blocks

This is an opt-in, non-breaking change. Using the should_load_separate_core_block_assets 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., developers can opt-in to this feature:

add_filter( 'should_load_separate_core_block_assets', '__return_true' );

Prior to WordPress 5.8, styles for all blocks were included in a style.css file that gets loaded on every page. By opting-in to separate styles loading, the following will happen:

  • The wp-block-library stylesheet changes: Instead of loading the wp-includes/css/dist/block-library/style.css file which contains all styles for all blocks, this handle will now load the (much smaller) wp-includes/css/dist/block-library/common.css file, which contains generic styles like the default colors definitions, basic styles for text alignments, and styles for the .screen-reader-text class.
  • Styles for blocks will only get enqueued when the block gets rendered on a page.

The above changes will only apply to the frontend of a site, so all editor styles will continue to work as they did before.

The difference between block themes and classic themes

Block themes

In a block theme, blocks get parsed before the <head> so we always know which blocks will be present prior to rendering a page. This makes it possible to add the block styles to the <head> of our document.

Classic themes

In a classic, php-based theme, when a page starts to render, WordPress is not aware which blocks exist on a page and which don’t. Blocks gets parsed on render, and what that means is that block-styles don’t get added in the <head> of the page. Instead, they are added to the footer, when print_late_styles() runs.

If you have an existing theme and you want to opt-in to this improvement, you will need to test your theme for style priorities. Opting-in to separate styles loading in a classic theme means that the loading order of styles changes. Block styles that used to be in the head will move to the footer, so you will need to check your theme’s styles and make sure any opinionated styles you add to blocks have a higher priority than coreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress. styles.

Taking advantage of separate styles loading to add 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/theme styles to blocks

It is possible to use this new feature to attach styles to existing block-styles, by inlining them.

If your theme adds styles to blocks, instead of loading a single file containing all styles for all blocks, you can split styles and have a single file per-block. This will allow you to only load your theme’s (or plugin’s) block styles only when a block exists on a page.

The function below is an example implementation of how to do that, with some additional tweaks:

  • It works both in WordPress 5.8 and previous versions
  • It has a fallback in case the should_load_separate_core_block_assets filter is disabled
  • It adds styles both in the editor and frontend
  • Checks for specific editor block styles.

Feel free to use this as an example, tweaking it to suit your needs and implementation.

/**
 * Attach extra styles to multiple blocks.
 */
function my_theme_enqueue_block_styles() {
	// An array of blocks.
	$styled_blocks = [ 'paragraph', 'code', 'cover', 'group' ];

	foreach ( $styled_blocks as $block_name ) {
		// Get the stylesheet handle. This is backwards-compatible and checks the
		// availability of the `wp_should_load_separate_core_block_assets` function,
		// and whether we want to load separate styles per-block or not.
		$handle = (
			function_exists( 'wp_should_load_separate_core_block_assets' ) &&
			wp_should_load_separate_core_block_assets()
		) ? "wp-block-$block_name" : 'wp-block-library';

		// Get the styles.
		$styles = file_get_contents( get_theme_file_path( "styles/blocks/$block_name.min.css" ) );

		// Add frontend styles.
		wp_add_inline_style( $handle, $styles );

		// Add editor styles.
		add_editor_style( "styles/blocks/$block_name.min.css" );
		if ( file_exists( get_theme_file_path( "styles/blocks/$block_name-editor.min.css" ) ) ) {
			add_editor_style( "styles/blocks/$block_name-editor.min.css" );
		}
	}
}
// Add frontend styles.
add_action( 'wp_enqueue_scripts', 'my_theme_enqueue_block_styles' );
// Add editor styles.
add_action( 'admin_init', 'my_theme_enqueue_block_styles' );

Inlining small assets

In some cases small stylesheets get loaded on WordPress sites. These stylesheets require the browser to make an additional request to get an asset, and while they benefit from caching, their small size doesn’t justify that extra request, and performance would improve if they were inlined.

To that end, an inlining mechanism was implemented. This is an opt-in feature, and can be handled on a per-stylesheet basis. Internally, only assets that have data for path defined get processed, so to opt-in, a stylesheet can add something like this:

wp_style_add_data( $style_handle, 'path', $file_path );

When a page gets rendered, stylesheets that have opted-in to get inlined get added to an array. Their size is retrieved using a filesize call (which is why the path data is necessary), and the array is then ordered by ascending size (smaller to larger stylesheet). We then start inlining these assets by going from smallest to largest, until a 20kb limit is reached.

A filter is available to change that limit to another value, and can also be used to completely disable inlining.

To completely disable small styles inlining:

add_filter( 'styles_inline_size_limit', '__return_zero' );

To change the total inlined styles limit to 50kb:

add_filter( 'styles_inline_size_limit', function() {
	return 50000; // Size in bytes.
});

Inlining these styles happens by changing the src of the style to false, and then adding its contents as inline data. This way we avoid backwards-compatibility issues in themes and any additional styles attached to these stylesheets using wp_add_inline_style will still be printed.

Please note that if a stylesheet opts-in to get inlined, that is no guarantee that it will get inlined.

If for example on a page there are 30 stylesheets that are 1kb each, and they all opt-in to be inlined, then only 20 of them will be converted from <link rel="stylesheet"/> to <style> elements. When the 20th stylesheet gets inlined the 20kb limit is reached and the inlining process stops. The remaining 10 stylesheets will continue functioning like before and remain <link> elements.

If your theme opts-in to the separate block-styles, core block styles by default have path defined so they can all be inlined.

Props @sergeybiryukov for proofreading this dev-note.

#5-8, #dev-notes

Blocks in an iframed (template) editor

The new template editor is loaded in an iframeiframe iFrame is an acronym for an inline frame. An iFrame is used inside a webpage to load another HTML document and render it. This HTML document may also contain JavaScript and/or CSS which is loaded at the time when iframe tag is parsed by the user’s browser. to isolate it from the rest of the adminadmin (and super admin) screen. This has the following benefits:

  • Admin styles no longer affect the editor content, so there’s no need to reset any of these rules.
  • Content styles no longer affect the admin screen, so 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. and theme CSSCSS Cascading Style Sheets. rules no longer need to be prefixed.
  • Viewport relative CSS units will work correctly. The dimensions of the editor content is usually not the same as the dimensions of the admin page, so without an iframe units like vw will be relative to the admin page.
  • Media queries will also work natively, without needing to fake them, as we did before, which is fragile.
  • In general, it makes the lives of block and theme authors easier because styles from the front-end can be dropped in with very little, if nothing, to adjust. This also applies to lighter blocks, where the editor DOM structure matches the front-end, which we highly recommend when possible.
  • With a separate window for the editor content, it’s possible for the selection in the editor to remain visible while also having a (collapsed) selection in the editor UIUI User interface, for example an input field for a URLURL A specific web address of a website or web page on the Internet, such as a website’s URL www.wordpress.org.

We currently only iframe new editors. While the new template editor has been iframed, the post editor remains unchanged. We do this to gradually test how existing blocks from plugins work within an iframed editor, since there are cases where a block could look broken or (less likely) error. We hereby urge 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 authors to test their blocks with the new template editor and contact us if they need help to adjust blocks to work in the iframe.

Document and window

The iframe will have a different document and window than the admin page, which is now the parent window. Editor scripts are loaded in the admin page, so accessing the document or window to do something with the content will no longer work.

Most blocks written in ReactReact React is a JavaScript library that makes it easy to reason about, construct, and maintain stateless and stateful user interfaces. https://reactjs.org/. should continue to work properly, except if you rely on document or window. To fix, you need to create ref to access the relative document (ownerDocument) or window (defaultView). Regardless of the iframe, it is good practice to do this and avoid the use of globals.

const ref = useRef();
useEffect( () => {
  const { ownerDocument } = ref.current;
  const { defaultView } = ownerDocument;
  // Set ownerDocument.title for example.
}, [] );
const props = useBlockProps( { ref } );

If you attach event handlers, remember that the useEffect callback will not be called if the ref changes, so it is good practice to use the new useRefEffect APIAPI An API or Application Programming Interface is a software intermediary that allows programs to interact with each other and share data in limited, clearly defined ways., which will call the given callback if the ref change in addition to any dependencies passed.

const ref = useRefEffect( ( element ) => {
  const { ownerDocument } = element;
  const { defaultView } = ownerDocument;
  defaultView.addEventListener( ... );
  return () => {
	defaultView.removeEventListener( ... );
  };
}, [] );
const props = useBlockProps( { ref } );

Other frameworks and libraries

For the editor, scripts such as jQuery are loaded in the parent window (admin page), which is fine. When using these to interact with a block in the iframe, you should pass the element reference.

const ref = useRefEffect( ( element ) => {
  jQuery( element ).masonry( … );
  return () => {
    defaultView.jQuery( element ).masonry( 'destroy' );
  }
}, [] );
const props = useBlockProps( { ref } )

But what if the library is using the global window or document and it’s out of your control?

Submit an issue or PR for the library to use ownerDocument and defaultView instead of the globals. Ideally, any library should allow initialisation with an element in an iframe as the target. It’s never impossible. Feel free to contact us to mention the issue.

In the meantime, you can use the script that is loaded inside the iframe. We’ve loaded all front-end scripts in the iframe to fix these cases, but note that ideally you shouldn’t use scripts loaded in the iframe at all. You can use defaultView to access the script.

const ref = useRefEffect( ( element ) => {
  const { ownerDocument } = element;
  const { defaultView } = ownerDocument;

  // Use the script loaded in the iframe.
  // Script are loaded asynchronously, so check is the script is loaded.
  // After the dependencies have loaded, the block will re-render.
  if ( ! defaultView.jQuery ) {
    return;
  }

  defaultView.jQuery( element ).masonry( … );
  return () => {
    defaultView.jQuery( element ).masonry( 'destroy' );
  }
} );
const props = useBlockProps( { ref } );

And that’s it! In summary, any problem that a block might have in the iframe is caused by using the document or window global at the root of it, either in the block’s code or a third party library. Ideally, all code uses the ownerDocument and defaultView relative properties.

#5-8, #dev-notes, #gutenberg

On layout and content width in WordPress 5.8

WordPress 5.8 introduces Global Settings and Global Styles. They allow theme authors to control and style the available features in the editor and the different blocks using a theme.jsonJSON JSON, or JavaScript Object Notation, is a minimal, readable format for structuring data. It is used primarily to transmit data between a server and web application, as an alternative to XML..

By using a theme.json file, in addition to the Global styles and settings capabilities, theme authors opt-in into the layout feature for 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. containers.

Layout config

Historically, themes had the responsibility to provide CSSCSS Cascading Style Sheets. styles in order to support aligning content (left, right). With the introduction of the block editor in WordPress 5.0, new alignments has been added to the mix (wide, full). In addition to that, the block editor allowed users to use container blocks (group, columns blocks) which potentially can change how their inner blocks are positioned and aligned. Taking all these variations into consideration has become a very difficult task for theme authors. To address these issues, WordPress 5.8 introduces the layout feature and config.

How do I migrate my theme

Themes that have a centered content area, need to define a layout setting in their `theme.json` file:

{
   "settings": {
       "layout": {
           "contentSize": "800px",
           "wideSize": "1000px"
       }
   }
}  

The block-editor will automatically read this config and provide the corresponding styles in the editor. It will allow all alignments to work properly without requiring the `add_theme_support( ‘align-wide’ )` call.

Themes are still required to provide the corresponding styles in the frontend of their sites, something like:

.entry-content > * {
    max-width: 800px;
    margin-left: auto !important;
    margin-right: auto !important;
}

.entry-content > .alignwide {
    max-width: 1000px;
}

.entry-content > .alignfull {
    max-width: none;
}

.entry-content > .alignleft {
    float: left;
	margin-right: 2em;
}

.entry-content > .alignright {
    float: right;
	margin-right: 2em;
}

Note:

It’s not possible for WordPress to generate these styles automatically for all themes because the entry-content className in the example above is not mandatory and may not exist. In the future, with the introduction of the upcoming block themes, these styles won’t be needed anymore.

Nested Blocks

For themes with the layout config enabled, container blocks (like group blocks) do not automatically inherit the layout config. Meaning the blocks added inside the containers will by default take all the available space and not have any wide/full alignments options unless the user defines the wide and content sizes for that particular container block or “inherits” the config from the default layout.

This also means that themers can drop any alignment specific CSS that was added specifically to support nested blocks.

#5-8, #dev-notes, #gutenberg

Introducing “Update URI” plugin header in WordPress 5.8

WordPress 5.8 introduces a new 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. available for 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 authors. This allows third-party plugins to avoid accidentally being overwritten with an update of a plugin of a similar name from the 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/ Plugin Directory.

Previously, any custom plugin which used the same slug than a plugin hosted on WordPress.org was taking a significant risk of being overwritten by an update of the latter.

WordPress 5.8 introduces a new Update URI plugin header field. If the value of this new field matches any URI other than https://wordpress.org/plugins/{$slug}/ or w.org/plugin/{$slug}, WordPress will not attempt to update it.

If set, the Update URI header field should be a valid URI and have a unique hostname.

Please note that authors of plugins hosted by WordPress.org don’t need to use this new header.

Some examples include:

  • Update URI: https://wordpress.org/plugins/example-plugin/
  • Update URI: https://example.com/my-plugin/
  • Update URI: my-custom-plugin-name

Update URI: false also works, and unless there is some code handling the false hostname (see the hook introduced below), the plugin will not be updated.

If the header is used on a w.org hosted plugin, the WordPress.org APIAPI An API or Application Programming Interface is a software intermediary that allows programs to interact with each other and share data in limited, clearly defined ways. will only return updates for the plugin if it matches the following format:

  • https://wordpress.org/plugins/{$slug}/
  • w.org/plugin/{$slug}

If the header has any other value, the API will not return any result. It will ignore the plugin for update purposes.

Additionally, WordPress 5.8 introduce the update_plugins_{$hostname} 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., which third-party plugins can use to offer updates for a given hostname.

This new hook filters the update response for a given plugin hostname. The dynamic portion of the hook name, $hostname, refers to the hostname of the URI specified in the Update URI header field.

The hook has four arguments:

  • $update: The plugin update data with the latest details. Default false.
  • $plugin_data: The list of headers provided by the plugin.
  • $plugin_file: The plugin filename.
  • $locales: Installed locales to look translations for.

They can be used to filter the update response in multiple use cases.

For reference, see tickets #32101, #23318, and changelog [50921].

Thanks @milana_cap for proofreading.

#5-8, #dev-notes

Various Block Editor API removals in WordPress 5.8

Removed APIs

Keeping deprecated JavaScriptJavaScript JavaScript or JS is an object-oriented computer programming language commonly used to create interactive effects within web browsers. WordPress makes extensive use of JS for a better user experience. While PHP is executed on the server, JS executes within a user’s browser. https://www.javascript.com/. APIs around has a cost on performance and bundle size. This means at some point we need to consider removing some of the very old deprecated APIs, especially the ones with very low usage. WordPress 5.8 does remove two APIs that were deprecated on WordPress 5.2.

  • EditorGlobalKeyboardShortcuts component, this was a component used to define some keyboard shortcuts of 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, it was not really meant to be used by third-party developers. We verified that it’s not used by any 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 in the repository but if you rely on this component, it should be safe to just replace with VisualEditorGlobalKeyboardShortcuts.
  • The hasUploadPermissions selector from the core store. We contacted all the three plugins in the repository that were still using this APIAPI An API or Application Programming Interface is a software intermediary that allows programs to interact with each other and share data in limited, clearly defined ways.. If you’re still relying on this selector on a private site/plugin, it can be safely replaced with select( 'core' ).canUser( 'create', 'media' )

Removed blocks

Before WordPress 5.0 and in the very early days of the GutenbergGutenberg The Gutenberg project is the new Editor Interface for WordPress. The editor improves the process and experience of creating new content, making writing rich content much simpler. It uses ‘blocks’ to add richness rather than shortcodes, custom HTML etc. https://wordpress.org/gutenberg/ plugin, we used to have a block called Subheading, this block has never been included in WordPress CoreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress. as stable, it was hidden and deprecated very early. We expect its usage to be very small. WordPress 5.8 removes the code of this block meaning that if you open content relying on that block in the editor, it will ask you to fallback to the HTMLHTML HyperText Markup Language. The semantic scripting language primarily used for outputting content in web browsers. block instead. We don’t expect this to have a noticeable impact on the frontend of your site.

#5-8, #block-editor, #dev-notes

REST API Changes in WordPress 5.8

The following is a snapshot of some of the changes 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/. in WordPress 5.8. For more details, see the full list of closed tickets.

Widgets

WordPress 5.8 sees the introduction of a new 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.-based widgets editor and with it the creation of several REST API endpoints dedicated to widgetWidget A WordPress Widget is a small block that performs a specific function. You can add these widgets in sidebars also known as widget-ready areas on your web page. WordPress widgets were originally created to provide a simple and easy-to-use way of giving design and structure control of the WordPress theme to the user. management. Before diving in to how the new endpoints operate, I’d like to provide some background about how widgets work that should make the following sections more clear.

Instance Widgets

The predominant way to create widgets is to subclass the WP_Widget base class and register the widget with register_widget. These are referred to as “multi” widgets. These widgets have multiple instances that are identified by their number, an incrementing integer for each widget type.

Each instance has its own setting values. These are stored and fetched by WP_Widget which allows for the REST API to include these values. However, since a widget’s instance can contain arbitrary data, for example a DateTime object, the REST API cannot always serialize a widget to JSONJSON JSON, or JavaScript Object Notation, is a minimal, readable format for structuring data. It is used primarily to transmit data between a server and web application, as an alternative to XML.. As such, a widget’s data is always serialized using the PHPPHP The web scripting language in which WordPress is primarily architected. WordPress requires PHP 5.6.20 or higher serialize function and then base64 encoded. This data is also exposed with a hash value which is a wp_hash signature of this value to prevent clients from sending arbitrary data to be deserialized with unserialize.

For widgets that can be safely accept and expose their instance data as JSON, pass the show_instance_in_rest flag in the $widget_options parameter.

class ExampleWidget extends WP_Widget {
    ...
    /**
     * Sets up the widget
     */
    public function __construct() {
        $widget_ops = array(
            // ...other options here
            'show_instance_in_rest' => true,
            // ...other options here
        );
        parent::__construct( 'example_widget', 'ExampleWidget', $widget_ops );
    }
    ...
}

Reference Widgets

Far less common, but still supported, are widgets that are registered using wp_register_sidebar_widget and wp_register_widget_control directly. These are referred to as “reference”, “function-based”, or “non-multi” widgets. These widgets can store their data in an arbitrary location. As such, their instance values are never included in the REST API.

Widget Types

Accessible via /wp/v2/widget-types, the widget types endpoint describes the different widget types that are registered on the server. The endpoint is accessible to users who have permission to edit_theme_options. By default, this is limited to Administrator users.

Response Format

{
  "id": "pages",
  "name": "Pages",
  "description": "A list of your site’s Pages.",
  "is_multi": true,
  "classname": "widget_pages",
  "_links": {
    "collection": [
      {
        "href": "https://trunk.test/wp-json/wp/v2/widget-types"
      }
    ],
    "self": [
      {
        "href": "https://trunk.test/wp-json/wp/v2/widget-types/pages"
      }
    ]
  }
}

Encode Endpoint

Multi widgets have access to the /wp/v2/widget-types/<widget>/encode endpoint. This endpoint is used to convert htmlHTML HyperText Markup Language. The semantic scripting language primarily used for outputting content in web browsers. form data for the widget to the next instance for the widget, render the widget form, and render the widget preview.

For example, let’s say we want to interact with the MetaMeta Meta is a term that refers to the inside workings of a group. For us, this is the team that works on internal WordPress sites like WordCamp Central and Make WordPress. widget. First, we’ll want to request the widget form from the server.

POST /wp/v2/widget-types/meta/encode
{
  "instance": {},
  "number": 1
}

For now, let’s assume we’re working with a new widget. The instance is empty because this is a new widget, so we’ll be rendering an empty form. The number argument can be omitted, but including one is recommended to provide stable input ids. You’ll receive a response similar to this. The widget preview has been snipped for brevity.

{
  "form": "<p><label for=\"widget-meta-1-title\">Title:</label><input class=\"widefat\" id=\"widget-meta-1-title\" name=\"widget-meta[1][title]\" type=\"text\" value=\"\" /></p>",
  "preview": "<div class=\"widget widget_meta\">...</div>",
  "instance": {
    "encoded": "YToxOntzOjU6InRpdGxlIjtzOjA6IiI7fQ==",
    "hash": "77e9f20acb54fa4f77de5a865333c0e6",
    "raw": {
      "title": ""
    }
  }
}

The provided form can then be rendered and edited by the user. When you want to render a new preview or are ready to begin saving, call the encode endpoint again with the url encoded form data and the instance value returned from the first response.

POST /wp/v2/widget-types/meta/encode
{
  "instance": {
    "encoded": "YToxOntzOjU6InRpdGxlIjtzOjA6IiI7fQ==",
    "hash": "77e9f20acb54fa4f77de5a865333c0e6",
    "raw": {
      "title": ""
    }
  },
  "number": 1,
  "form_data": "widget-meta%5B1%5D%5Btitle%5D=Site+Info"
}

The REST API will call the widget’s update function to calculate the new instance based on the provided form data. The instance object can then be used to save a widget via the widgets endpoint.

{
  "form": "<p><label for=\"widget-meta-1-title\">Title:</label><input class=\"widefat\" id=\"widget-meta-1-title\" name=\"widget-meta[1][title]\" type=\"text\" value=\"Site Info\" /></p>",
  "preview": "<div class=\"widget widget_meta\">...</div>",
  "instance": {
    "encoded": "YToxOntzOjU6InRpdGxlIjtzOjk6IlNpdGUgSW5mbyI7fQ==",
    "hash": "0e9a5bff2d28cba322c8cd27cd4e77af",
    "raw": {
      "title": "Site Info"
    }
  }
}

Widgets Endpoint

The widgets endpoint is used for performing CRUDCRUD Create, read, update and delete, the four basic functions of storing data. (More on Wikipedia.) operations on the saved widgets. Like the widget types endpoint, the widgets endpoints required the edit_theme_options capability to access.

To retrieve widgets, make a GET request to the /wp/v2/widgets endpoint. The sidebar parameter can be used to limit the response to widgets belonging to the requested sidebarSidebar A sidebar in WordPress is referred to a widget-ready area used by WordPress themes to display information that is not a part of the main content. It is not always a vertical column on the side. It can be a horizontal rectangle below or above the content area, footer, header, or any where in the theme..

To create a widget, for instance the widget from our previous example, make a POST request to the /wp/v2/widgets endpoint. The instance is the same value returned from the encode endpoint. The id_base is the unique identifier for the widget type and sidebar is the id of the sidebar to assign the widget to. Both are required.

POST /wp/v2/widgets
{
	"instance": {
		"encoded": "YToxOntzOjU6InRpdGxlIjtzOjk6IlNpdGUgSW5mbyI7fQ==",
		"hash": "0e9a5bff2d28cba322c8cd27cd4e77af",
		"raw": {
			"title": "Site Info"
		}
	},
	"sidebar": "sidebar-1",
	"id_base": "meta"
}

The endpoint will return information about the newly created widget.

{
  "id": "meta-1",
  "id_base": "meta",
  "sidebar": "sidebar-1",
  "rendered": "<div class=\"widget widget_meta\">...</div>",
  "rendered_form": "<p><label for=\"widget-meta-1-title\">Title:</label><input class=\"widefat\" id=\"widget-meta-1-title\" name=\"widget-meta[1][title]\" type=\"text\" value=\"Site Info\" /></p>",
  "instance": {
    "encoded": "YToxOntzOjU6InRpdGxlIjtzOjk6IlNpdGUgTWV0YSI7fQ==",
    "hash": "dac44c3ebfa0428fed61829fa151e4e8",
    "raw": {
      "title": "Site Info"
    }
  },
  "_links": {
    "self": [
      {
        "href": "https://trunk.test/wp-json/wp/v2/widgets/meta-1"
      }
    ],
    "collection": [
      {
        "href": "https://trunk.test/wp-json/wp/v2/widgets"
      }
    ],
    "about": [
      {
        "embeddable": true,
        "href": "https://trunk.test/wp-json/wp/v2/widget-types/meta"
      }
    ],
    "wp:sidebar": [
      {
        "href": "https://trunk.test/wp-json/wp/v2/sidebars/sidebar-1/"
      }
    ],
    "curies": [
      {
        "name": "wp",
        "href": "https://api.w.org/{rel}",
        "templated": true
      }
    ]
  }
}

Since the meta widget (and all other built-in widgets) is registered with show_instance_in_rest enabled you could bypass the encode endpoint and use instance.raw instead. For example, if we wanted to update the widget to have a new title, we could make the following PUT request to /wp/v2/widgets/meta-1.

PUT /wp/v2/widgets/meta-1
{
	"instance": {
		"raw": {
			"title": "Site Meta"
		}
	}
}

A PUT request can also be made to update the sidebar assigned to a widget by passing a new sidebar id in the request.

To delete a widget, send a DELETE request to the individual widget route. By default, deleting a widget will move a widget to the Inactive Widgets area. To permanently delete a widget, use the force parameter. For example: DELETE /wp/v2/widgets/meta-1?force=true.

Sidebars Endpoints

Found under /wp/v2/sidebars, the sidebars endpoint is used to manage a site’s registered sidebars (widget areas) and their assigned widgets. For example, the following is the response for the first footer area in the Twenty Twenty theme.

{
  "id": "sidebar-1",
  "name": "Footer #1",
  "description": "Widgets in this area will be displayed in the first column in the footer.",
  "class": "",
  "before_widget": "<div class=\"widget %2$s\"><div class=\"widget-content\">",
  "after_widget": "</div></div>",
  "before_title": "<h2 class=\"widget-title subheading heading-size-3\">",
  "after_title": "</h2>",
  "status": "active",
  "widgets": [
    "recent-posts-2",
    "recent-comments-2",
    "meta-1"
  ],
  "_links": {
    "collection": [
      {
        "href": "https://trunk.test/wp-json/wp/v2/sidebars"
      }
    ],
    "self": [
      {
        "href": "https://trunk.test/wp-json/wp/v2/sidebars/sidebar-1"
      }
    ],
    "wp:widget": [
      {
        "embeddable": true,
        "href": "https://trunk.test/wp-json/wp/v2/widgets?sidebar=sidebar-1"
      }
    ],
    "curies": [
      {
        "name": "wp",
        "href": "https://api.w.org/{rel}",
        "templated": true
      }
    ]
  }
}

The widgets property contains an ordered list of widget ids. While all other properties are readonly, the widgets property can be used to reorder a sidebar’s assigned widgets. Any widget ids omitted when updating the sidebar will be assigned to the Inactive Widgets sidebar area.

For example, making a PUT request to /wp/v2/sidebars/sidebar-1 with the following body will remove the Recent Comments widget, and move the Meta widget to the top of the sidebar.

PUT /wp/v2/sidebars/sidebar-1
{
  "widgets": [
    "meta-1",
    "recent-posts-2"
  ]
}

For more information about the changes to widgets in 5.8, check out the Block-based Widgets Editor dev notedev note Each important change in WordPress Core is documented in a developers note, (usually called dev note). Good dev notes generally include: a description of the change; the decision that led to this change a description of how developers are supposed to work with that change. Dev notes are published on Make/Core blog during the beta phase of WordPress release cycle. Publishing dev notes is particularly important when plugin/theme authors and WordPress developers need to be aware of those changes.In general, all dev notes are compiled into a Field Guide at the beginning of the release candidate phase..

Additional Changes

Posts Collection Tax Query Accepts operator

By default, a post must contain at least one of the requested terms to be included in the response. As of [51026], the REST API accepts a new operator property that can be set to AND to require a post to contain all of the requested terms.

For example, /wp/v2/posts?tags[terms]=1,2,3&tags[operator]=AND will return posts that have tags with the ids of 1, 2, and 3.

See #41287 for more details.

Props to @noisysocks for reviewing.

#5-8, #dev-notes, #rest-api

Block-based Widgets Editor in WordPress 5.8

WordPress 5.8 introduces a new 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.-based widgets editor to the Widgets screen (Appearance → Widgets) and CustomizerCustomizer Tool built into WordPress core that hooks into most modern themes. You can use it to preview and modify many of your site’s appearance settings. (Appearance → Customize → Widgets). The new editor allows users to add blocks to their widgetWidget A WordPress Widget is a small block that performs a specific function. You can add these widgets in sidebars also known as widget-ready areas on your web page. WordPress widgets were originally created to provide a simple and easy-to-use way of giving design and structure control of the WordPress theme to the user. areas using the familiar block editor interface introduced in WordPress 5.0. This gives users powerful new ways to customise their sites using the rich library of coreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress. and third party blocks. Existing widgets and third party widgets will continue to work and can be used alongside blocks.

Opting out of the block-based widgets editor

The block-based widgets editor is enabled in WordPress 5.8 by default. There are several ways to restore the classic editor:

  • A theme author may include remove_theme_support( 'widgets-block-editor' ). Learn more.
  • A site administrator may use the new use_widgets_block_editor 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.. Learn more.
  • A user may install and activate the Classic Widgets plugin.

New Widgets screen

The widgets.php adminadmin (and super admin) screen (Appearance → Widgets) now loads a block-based widgets editor which exists in the @wordpress/edit-widgets package.

The editor is built using ReactReact React is a JavaScript library that makes it easy to reason about, construct, and maintain stateless and stateful user interfaces. https://reactjs.org/. and is similar to the editor used for posts and pages (@wordpress/edit-post) and uses many of the same subsystems: @wordpress/interface and @wordpress/components for UIUI User interface, @wordpress/block-editor for block editing, @wordpress/data and @wordpress/core-data for persisting changes, and so on.

A new filterable function, wp_use_widgets_block_editor(), is used by widgets.php to determine whether to load the new block-based editor or the classic editor.

The Widgets screen is extendable via block editor APIs such as registerPlugin, registerBlockType, registerBlockVariation, and so on.

The Widgets screen uses new 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/. endpoints which are detailed in a seperate dev note.

New Customizer control

The Widgets section in the Customizer (Appearance → Customize → Widgets) now loads a new control (WP_Sidebar_Block_Editor_Control) which contains an embedded block-based widgets editor that exists in the @wordpress/customize-widgets package.

The editor is built using React and uses @wordpress/block-editor and @wordpress/components to implement its block editing interface. It does not use @wordpress/data or @wordpress/core-data to persist changes. Instead, the existing Customizer JavaScript API is used.

A new filterable function, wp_use_widgets_block_editor(), is used by WP_Customize_Manager to determine whether or not to log the new block-based editor control or the classic editor control.

The block-based widgets editor in the Customizer is extendable via block editor APIs such as registerBlockType, registerBlockVariation, and so on.

New block: Legacy Widget

Existing widgets and third party widgets can be edited in the block-based widgets editor via the new Legacy Widget block. This block has an identifier of core/legacy-widget and exists in the @wordpress/widgets package. The Legacy Widget block is compatible with most third party widgets.

Broadly speaking, the Legacy Widget block has three states:

  1. Select. When first inserted, the block displays a list of widgets available to choose from. The list can be customised using the widget_types_to_hide_from_legacy_widget_block filter.
  2. Edit. When selected, the block displays the widget’s control form fields. This is determined by the widget’s WP_Widget::form() implementation.
  3. Preview. When not selected, the block displays a preview of how the widget will look once saved. This is determined by the widget’s WP_Widget::widget() implementation. A “No preview available.” message is automatically shown when widget() does not output any meaningful HTMLHTML HyperText Markup Language. The semantic scripting language primarily used for outputting content in web browsers.. Learn more.

The Legacy Widget block is not available in other block editors including the post editor, though this can be enabled for advanced use cases.

New widget: Block

Blocks added to widget areas are persisted using the same widget storage mechanism added in WordPress 2.8. Under the hood, each block is serialised into HTML and stored in a block widget. This is represented by a new WP_Widget_Block subclass that extends WP_Widget. A block widget is a specialised case of the HTML widget and works very similarly.

If blocks are added to a widget area, and then the block-based widgets editor is disabled, the blocks will remain visible on the frontend and in the classic widgets screen.

Tips to prepare for the new block-based widgets editor

Use the widget-added event to bind event handlers

The Legacy Widget block will display a widget’s control form in a way that is very similar to the Customizer and is therefore compatible with most third party widgets. Care must be taken, however, to always initialise event handlers when the widget-added jQuery event is triggered on document.

( function ( $ ) {
    $( document ).on( 'widget-added', function ( $control ) {
        $control.find( '.change-password' ).on( 'change', function () {
            var isChecked = $( this ).prop( 'checked' );
            $control.find( '.password' ).toggleClass( 'hidden', ! isChecked );
        } );
    } );
} )( jQuery );

Use block_categories_all instead of block_categories

The block_categories filter has been deprecated and will only be called in the post and page block editor. 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 developers that wish to support the widgets block editor should use the new block_categories_all filter which is called in all editors. See #52920 for more details.

Allow migrating from widgets to blocks

Many core and third party widgets have a functionally equivalent block. For example, core’s Recent Posts widget is analogous to core’s Latest Posts block.

In order to avoid duplicate functionality, is is recommended that plugin authors provide a way for users to convert their existing widgets to any equivalent block. WordPress 5.8 provides a mechanism for doing this using block transforms:

  1. Configure your widget to display its instance in the REST API by setting show_instance_in_rest to true in $widget_options.
  2. Add a block transform to your block from the core/legacy-widget block.
  3. Hide your widget from the Legacy Widget block using the widget_types_to_hide_from_legacy_widget_block filter.

There is a guide containing more detailed instructions in the Block Editor Handbook.

Don’t use @wordpress/editor

Many legacy widgets call the wp.editor.initialize() JavaScriptJavaScript JavaScript or JS is an object-oriented computer programming language commonly used to create interactive effects within web browsers. WordPress makes extensive use of JS for a better user experience. While PHP is executed on the server, JS executes within a user’s browser. https://www.javascript.com/. function to instantiate a TinyMCE editor. If a plugin or block uses the @wordpress/editor package and enqueues wp-editor as a script dependency, this will re-define the wp.editor global, often resulting in a wp.editor.initialize is undefined error.

Don’t use functions like is_admin() that won’t work in a REST API request

Because the Legacy Widget block makes REST API requests in order to render widgets, admin-only functions like is_admin() and is_plugin_available() are not available.


Written by @andraganescu and @noisysocks.
Thanks to @talldanwp, @isabel_brison, @kevin940726, and @get_dave for reviewing.

#5-8 #dev-notes #feature-widgets-block-editor #widgets #block-editor

Miscellaneous developer focused changes in WordPress 5.8


Update on July 1, 2021: Added new 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. info in RevisionsRevisions The WordPress revisions system stores a record of each saved draft or published update. The revision system allows you to see what changes were made in each revision by dragging a slider (or using the Next/Previous buttons). The display indicates what has changed in each revision. section. – @milana_cap


WordPress 5.8 brings a lot of smaller changes that developers should know about. Here’s a breakdown.

Build/Test Tools: Remove IE11 from the list of supported browsers

In WordPress 5.8, phase one of the dropping support for IE11 plan will take place. When considering three different data points, IE11 usage has fallen below a 1% average. After a discussion and debate, the decision was made to remove support for IE 11. In addition to opening the door for using more modern APIs, this will result in smaller script files, lower maintenance burden, and decreased build times.

The wp-polyfill script is responsible for ensuring all newer features function in the older browsers supported by WordPress. In past releases, this script was a copy of the file distributed in the @babel/polyfill package, which among other things, included regenerator-runtime.

This package was deprecated and has been replaced with the core-js package in the build process. core-js allows the polyfill file to be built dynamically, but no longer includes the regenerator-runtime script.

The regenerator-runtime script handle has been added to WordPress CoreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress., and has been added as a dependency to wp-polyfill in order to be backwards compatible with any 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 or theme registering wp-polyfill as a script dependency expecting regenerator-runtime to be present.

It is recommended that developers add the regenerator-runtime script as a dependency to any script that requires it. In future releases, removing regenerator-runtime as a dependency of wp-polyfill will be considered.

There are several other polyfill scripts included in WordPress for the sole purpose of IE11 support. They will continue to be included, but will no longer be loaded by default. They are:

  • wp-polyfill-dom-rect
  • wp-polyfill-element-closest
  • wp-polyfill-fetch
  • wp-polyfill-formdata
  • wp-polyfill-node-contains
  • wp-polyfill-object-fit
  • wp-polyfill-url

For more information, see #52941, #53077, and #53078.

Formatting: More consistency and control over wp_get_document_title()

In wp_get_document_title(), the returned value is currently passed directly through wptexturize(), convert_chars(), and capital_P_dangit(), and is done so after the document_title_parts filter is run.

This makes it impossible to fully control the output of wp_get_document_title() and is inconsistent with how other similar text is processed with these functions.

The new document_title filter, which is run immediately before returning the results of the wp_get_document_title() function, moves the three formatting functions mentioned above to the new filter hook. This allows developers to further modify the title after being prepared by WordPress, or to modify the functions hooked to this filter as they wish.

For more information, see #51643.

General: Consistent type for integer properties of WP_Post, WP_Term, WP_User and a bookmark object

Some properties of the WP_PostWP_Term, and WP_User classes are documented as integers, so it should be a safe assumption to always treat them as such. However, that is not the case when get_post() or get_term() is called with an editattribute, or js context, because all values are run through esc_attr() or esc_js() in that case, and these properties are unexpectedly converted to strings.

This applies to the following functions:

  • sanitize_post_field()
  • sanitize_term_field()
  • sanitize_user_field()
  • sanitize_bookmark_field()

and the following properties:

  • WP_Post::ID
  • WP_Post::post_parent
  • WP_Post::menu_order
  • WP_Term::term_id
  • WP_Term::term_taxonomy_id
  • WP_Term::parent
  • WP_Term::count
  • WP_Term::term_group
  • WP_User::ID
  • $bookmark::link_id
  • $bookmark::link_rating

As WordPress moves towards strict type comparisons (see #52627 or #52482) it is important to make the type of these properties consistent in all contexts, so that using strict comparison does not cause unexpected issues.

In WordPress 5.8, these functions and properties will now reliably return an be set to integer values.

For more information, see #53235.

Posts/Post Types: Use _prime_post_caches() for speeding up cached get_pages() call

The get_pages() function uses a cache containing the ID of pages matching parameters of a previous call.

The IDs are, on a subsequent call with the same parameters, inflated using the get_post() function call. This works well in terms of the same request, as all the pages were previously added to the in-memory cache.

However, on a subsequent request, when the cache is hit, there are likely no pages already in the in-memory cache, and those need to be fetched from the backend cache server, one by one.

By taking advantage of wp_cache_get_multiple() instead of fetching each individual page from the backend cache server one by one, sites with persistent cache backend will have improved speed, but also sites without a persistent cache backend will benefit from the bulk SQL query constructed by the _prime_post_caches() function.

The performance gains should be most noticeable in case a site has a lot of pages which are being requested via get_pages() function.

For more information, see #51469.

Users: Pass $userdata to the actions and filters in wp_insert_user()

There are several action and filter 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. within wp_insert_user() that would benefit from being able to access the raw $userdata array passed into the function. One use case where this would be useful is extending the wp user import-csv command in WP-CLIWP-CLI WP-CLI is the Command Line Interface for WordPress, used to do administrative and development tasks in a programmatic way. The project page is http://wp-cli.org/ https://make.wordpress.org/cli/. This command is a wrapper for wp_insert_user() but it’s not possible to provide custom user metaMeta Meta is a term that refers to the inside workings of a group. For us, this is the team that works on internal WordPress sites like WordCamp Central and Make WordPress. fields.

Here are the hooks gaining a new parameter:

  • wp_pre_insert_user_data (filter)
  • insert_user_meta (filter)
  • profile_update (action)
  • user_register (action)

This will allow hooked functions to perform more contextual adjustments to new users, and makes supplying custom user meta fields possible.

For more information, see #53110.

Media: Introduce image_editor_output_format filter

As detailed in a previously published dev note, WordPress 5.8 now supports the WebP image format.

WebP is a modern image format that provides improved lossless and lossy compression for images on the web. WebP images are around 30% smaller on average than their JPEG or PNG equivalents, resulting in sites that are faster and use less bandwidth. WebP is supported in all modern browsers according to caniuse.

WordPress 5.8 adds WebP support by @adamsilverstein

When images are uploaded, WordPress generates smaller sub sizes as defined using add_image_size(). By default, WordPress will generate these sub sizes in the same format as the original. Because of the performance benefits of the WebP format, it may be desirable for sub sizes to be generated in WebP instead of the original format.

In WordPress 5.8, the new image_editor_output_format filter hook can be used to change the file format used for image sub sizes. This can be used to switch all sub sizes to WebP, or any other desired format (JPEG, etc.).

The following example shows how to generate all sub sizes for JPG images using WebP:

<?php
function mysite_wp_image_editor_output_format( $formats ) {
	$formats['image/jpg'] = 'image/webp';

	return $formats;
}
add_filter( 'image_editor_output_format', 'mysite_wp_image_editor_output_format' );

Note: both the GD and ImageMagick libraries support the WebP format in both lossy and lossless. However, only ImageMagick supports animated images.

Setting the output format to WebP will verify if the web server supports it, and if not it will not change the format, i.e. won’t work.

For more information, see #52867.

General: Pass the scheme to all the *_url filters

A new parameter representing the URLURL A specific web address of a website or web page on the Internet, such as a website’s URL www.wordpress.org $scheme has been added to admin_url, includes_url, network_admin_url and user_admin_url filters. This parameter is used for giving context to the URL (such as http, https, login, login_post, admin, relative or null) and was already present in other URL related filters (home_url, rest_url, site_url, to name a few).

For more information, see #52813.

Posts/Post Types: Improve post_exists() query

In previous releases, the post_exists() function did not make use of the database indexes available and was generating a poorly performing query. A new $status parameter has been added to allow developers to specify post_type, post_date and post_status to ensure that the wp_posts table’s type_status_date index is used when determining if a post exists.

For more information, see #34012.

Themes: Introduce the delete_theme and deleted_theme action hooks

These new theme action hooks bring parity to the plugin deletion process and fire immediately before and after an attempt to delete a theme, respectively.

For more information see #16401.

Posts/Post Types: Revisions are now enabled for Reusable Blocks post type

As per ticketticket Created for both bug reports and feature development on the bug tracker. #53072, the wp_block post type –which is used for Reusable blocks– now supports revisions. It allows users and developers to rely on revision history for their Reusable blocks.

Changes in the_password_form filter

As per ticket #29008, the the_password_form filter now passes the post object so it can be used by developers to directly get the current post data when they override the password form rendering. This closes a long awaited ticket.

Revisions: Add a post type-specific filter to wp_revisions_to_keep()

A new wp_{$post_type}_revisions_to_keep filter has been added that makes it convenient to filter the number of revisions created for a specific post type.

This new filter will override both the value of WP_POST_REVISIONS and the wp_revisions_to_keep filter.

For more information, see #51550.


Last modified on Thursday July 1, 2021 at 10:43 UTC.

Props @desrosj, @azaozz and @audrasjb for review and additional content.

#5-8, #dev-notes

Block supports API updates for WordPress 5.8

Expanding on previously implemented 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. supports in WordPress 5.6 and 5.7, WordPress 5.8 introduces several new block supports flags and new options to customize your registered blocks.

New Supports

color._experimentalDuotone – Adding duotone support to your block is a new experimental feature. To test, set this property to a string that specifies the CSSCSS Cascading Style Sheets. selector where you want to apply duotone. For example, in your block metadata:

supports: {
    color: {
        _experimentalDuotone: '> .duotone-img'
    }
}

color.link – Support for link color was added, this mirrors the usage and support for color.text that was added in WP 5.6.

To use in your block, add the supports flag in the block metadata:

supports: {
    color: {
        link: true;
    }
}

You can define a default value, using attributes and it will also use the values set in theme.json if present. For example:

attributes: {
  style: {
      type: 'object',
      default: {
          color: {
              link: '#FF0000',
          }
      }

Related ticketticket Created for both bug reports and feature development on the bug tracker.: #31524

Stabilized Supports APIAPI An API or Application Programming Interface is a software intermediary that allows programs to interact with each other and share data in limited, clearly defined ways.

Two features that were experimental in WordPress 5.7 have been stabilized in WordPress 5.8

  • fontSize previously __experimentalFontSize
  • lineHeight previously __experimentalLineHeight

See Block Supports API documentation for usage details.

The spacing support was updated and expanded to work for server-side blocks, as well as adding granular support to configure spacing for sides (top, right, bottom, left) individually. For example:

supports: {
    spacing: {
        margin: true,  // Enable margin UI control.
        padding: true, // Enable padding UI control.
    }
}

The following example configures side support for just top and bottom:

supports: {
    spacing: {
        margin: [ 'top', 'bottom' ], // Enable margin for arbitrary sides.
        padding: true,               // Enable padding for all sides.
    }
}

The spacing supports can target specific blocks using theme.json, or it’s own attributes. For example, customizing the top and bottom margins for the core/separator block:

"styles": {
    "blocks": {
        "core/separator": {
            "spacing": {
                "margin": {
                    "top": "100px",
                    "bottom": "100px"
                }
            }
        }
    }
}

Props to @mkaz and @nosolosw for help with compiling this dev notedev note Each important change in WordPress Core is documented in a developers note, (usually called dev note). Good dev notes generally include: a description of the change; the decision that led to this change a description of how developers are supposed to work with that change. Dev notes are published on Make/Core blog during the beta phase of WordPress release cycle. Publishing dev notes is particularly important when plugin/theme authors and WordPress developers need to be aware of those changes.In general, all dev notes are compiled into a Field Guide at the beginning of the release candidate phase..

Related PRs: #31808, #31332

Tags: #5.8 #dev-notes #gutenberg