register_block_type_from_metadata( string $file_or_folder, array $args = array() ): WP_Block_Type|false

Registers a block type from the metadata stored in the block.json file.


Parameters

$file_or_folder string Required
Path to the JSON file with metadata definition for the block or path to the folder where the block.json file is located.
If providing the path to a JSON file, the filename must end with block.json.
$args array Optional
Array of block type arguments. Accepts any public property of WP_Block_Type. See WP_Block_Type::__construct() for information on accepted arguments.
More Arguments from WP_Block_Type::__construct( ... $args ) Array or string of arguments for registering a block type. Any arguments may be defined, however the ones described below are supported by default.
  • api_version string
    Block API version.
  • title string
    Human-readable block type label.
  • category string|null
    Block type category classification, used in search interfaces to arrange block types by category.
  • parent string[]|null
    Setting parent lets a block require that it is only available when nested within the specified blocks.
  • ancestor string[]|null
    Setting ancestor makes a block available only inside the specified block types at any position of the ancestor's block subtree.
  • icon string|null
    Block type icon.
  • description string
    A detailed block type description.
  • keywords string[]
    Additional keywords to produce block type as result in search interfaces.
  • textdomain string|null
    The translation textdomain.
  • styles array[]
    Alternative block styles.
  • variations array[]
    Block variations.
  • selectors array
    Custom CSS selectors for theme.json style generation.
  • supports array|null
    Supported features.
  • example array|null
    Structured data for the block preview.
  • render_callback callable|null
    Block type render callback.
  • attributes array|null
    Block type attributes property schemas.
  • uses_context string[]
    Context values inherited by blocks of this type.
  • provides_context string[]|null
    Context provided by blocks of this type.
  • block_hooks array[]
    Block hooks.
  • editor_script_handles string[]
    Block type editor only script handles.
  • script_handles string[]
    Block type front end and editor script handles.
  • view_script_handles string[]
    Block type front end only script handles.
  • editor_style_handles string[]
    Block type editor only style handles.
  • style_handles string[]
    Block type front end and editor style handles.

Default: array()


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Return

WP_Block_Type|false The registered block type on success, or false on failure.


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Source

File: wp-includes/blocks.php. View all references

function register_block_type_from_metadata( $file_or_folder, $args = array() ) {
	/*
	 * Get an array of metadata from a PHP file.
	 * This improves performance for core blocks as it's only necessary to read a single PHP file
	 * instead of reading a JSON file per-block, and then decoding from JSON to PHP.
	 * Using a static variable ensures that the metadata is only read once per request.
	 */
	static $core_blocks_meta;
	if ( ! $core_blocks_meta ) {
		$core_blocks_meta = require ABSPATH . WPINC . '/blocks/blocks-json.php';
	}

	$metadata_file = ( ! str_ends_with( $file_or_folder, 'block.json' ) ) ?
		trailingslashit( $file_or_folder ) . 'block.json' :
		$file_or_folder;

	$is_core_block = str_starts_with( $file_or_folder, ABSPATH . WPINC );

	if ( ! $is_core_block && ! file_exists( $metadata_file ) ) {
		return false;
	}

	// Try to get metadata from the static cache for core blocks.
	$metadata = false;
	if ( $is_core_block ) {
		$core_block_name = str_replace( ABSPATH . WPINC . '/blocks/', '', $file_or_folder );
		if ( ! empty( $core_blocks_meta[ $core_block_name ] ) ) {
			$metadata = $core_blocks_meta[ $core_block_name ];
		}
	}

	// If metadata is not found in the static cache, read it from the file.
	if ( ! $metadata ) {
		$metadata = wp_json_file_decode( $metadata_file, array( 'associative' => true ) );
	}

	if ( ! is_array( $metadata ) || empty( $metadata['name'] ) ) {
		return false;
	}
	$metadata['file'] = wp_normalize_path( realpath( $metadata_file ) );

	/**
	 * Filters the metadata provided for registering a block type.
	 *
	 * @since 5.7.0
	 *
	 * @param array $metadata Metadata for registering a block type.
	 */
	$metadata = apply_filters( 'block_type_metadata', $metadata );

	// Add `style` and `editor_style` for core blocks if missing.
	if ( ! empty( $metadata['name'] ) && str_starts_with( $metadata['name'], 'core/' ) ) {
		$block_name = str_replace( 'core/', '', $metadata['name'] );

		if ( ! isset( $metadata['style'] ) ) {
			$metadata['style'] = "wp-block-$block_name";
		}
		if ( current_theme_supports( 'wp-block-styles' ) && wp_should_load_separate_core_block_assets() ) {
			$metadata['style']   = (array) $metadata['style'];
			$metadata['style'][] = "wp-block-{$block_name}-theme";
		}
		if ( ! isset( $metadata['editorStyle'] ) ) {
			$metadata['editorStyle'] = "wp-block-{$block_name}-editor";
		}
	}

	$settings          = array();
	$property_mappings = array(
		'apiVersion'      => 'api_version',
		'title'           => 'title',
		'category'        => 'category',
		'parent'          => 'parent',
		'ancestor'        => 'ancestor',
		'icon'            => 'icon',
		'description'     => 'description',
		'keywords'        => 'keywords',
		'attributes'      => 'attributes',
		'providesContext' => 'provides_context',
		'usesContext'     => 'uses_context',
		'selectors'       => 'selectors',
		'supports'        => 'supports',
		'styles'          => 'styles',
		'variations'      => 'variations',
		'example'         => 'example',
	);
	$textdomain        = ! empty( $metadata['textdomain'] ) ? $metadata['textdomain'] : null;
	$i18n_schema       = get_block_metadata_i18n_schema();

	foreach ( $property_mappings as $key => $mapped_key ) {
		if ( isset( $metadata[ $key ] ) ) {
			$settings[ $mapped_key ] = $metadata[ $key ];
			if ( $textdomain && isset( $i18n_schema->$key ) ) {
				$settings[ $mapped_key ] = translate_settings_using_i18n_schema( $i18n_schema->$key, $settings[ $key ], $textdomain );
			}
		}
	}

	$script_fields = array(
		'editorScript' => 'editor_script_handles',
		'script'       => 'script_handles',
		'viewScript'   => 'view_script_handles',
	);
	foreach ( $script_fields as $metadata_field_name => $settings_field_name ) {
		if ( ! empty( $metadata[ $metadata_field_name ] ) ) {
			$scripts           = $metadata[ $metadata_field_name ];
			$processed_scripts = array();
			if ( is_array( $scripts ) ) {
				for ( $index = 0; $index < count( $scripts ); $index++ ) {
					$result = register_block_script_handle(
						$metadata,
						$metadata_field_name,
						$index
					);
					if ( $result ) {
						$processed_scripts[] = $result;
					}
				}
			} else {
				$result = register_block_script_handle(
					$metadata,
					$metadata_field_name
				);
				if ( $result ) {
					$processed_scripts[] = $result;
				}
			}
			$settings[ $settings_field_name ] = $processed_scripts;
		}
	}

	$style_fields = array(
		'editorStyle' => 'editor_style_handles',
		'style'       => 'style_handles',
	);
	foreach ( $style_fields as $metadata_field_name => $settings_field_name ) {
		if ( ! empty( $metadata[ $metadata_field_name ] ) ) {
			$styles           = $metadata[ $metadata_field_name ];
			$processed_styles = array();
			if ( is_array( $styles ) ) {
				for ( $index = 0; $index < count( $styles ); $index++ ) {
					$result = register_block_style_handle(
						$metadata,
						$metadata_field_name,
						$index
					);
					if ( $result ) {
						$processed_styles[] = $result;
					}
				}
			} else {
				$result = register_block_style_handle(
					$metadata,
					$metadata_field_name
				);
				if ( $result ) {
					$processed_styles[] = $result;
				}
			}
			$settings[ $settings_field_name ] = $processed_styles;
		}
	}

	if ( ! empty( $metadata['blockHooks'] ) ) {
		/**
		 * Map camelCased position string (from block.json) to snake_cased block type position.
		 *
		 * @var array
		 */
		$position_mappings = array(
			'before'     => 'before',
			'after'      => 'after',
			'firstChild' => 'first_child',
			'lastChild'  => 'last_child',
		);

		$settings['block_hooks'] = array();
		foreach ( $metadata['blockHooks'] as $anchor_block_name => $position ) {
			// Avoid infinite recursion (hooking to itself).
			if ( $metadata['name'] === $anchor_block_name ) {
				_doing_it_wrong(
					__METHOD__,
					__( 'Cannot hook block to itself.' ),
					'6.4.0'
				);
				continue;
			}

			if ( ! isset( $position_mappings[ $position ] ) ) {
				continue;
			}

			$settings['block_hooks'][ $anchor_block_name ] = $position_mappings[ $position ];
		}
	}

	if ( ! empty( $metadata['render'] ) ) {
		$template_path = wp_normalize_path(
			realpath(
				dirname( $metadata['file'] ) . '/' .
				remove_block_asset_path_prefix( $metadata['render'] )
			)
		);
		if ( $template_path ) {
			/**
			 * Renders the block on the server.
			 *
			 * @since 6.1.0
			 *
			 * @param array    $attributes Block attributes.
			 * @param string   $content    Block default content.
			 * @param WP_Block $block      Block instance.
			 *
			 * @return string Returns the block content.
			 */
			$settings['render_callback'] = static function ( $attributes, $content, $block ) use ( $template_path ) {
				ob_start();
				require $template_path;
				return ob_get_clean();
			};
		}
	}

	/**
	 * Filters the settings determined from the block type metadata.
	 *
	 * @since 5.7.0
	 *
	 * @param array $settings Array of determined settings for registering a block type.
	 * @param array $metadata Metadata provided for registering a block type.
	 */
	$settings = apply_filters(
		'block_type_metadata_settings',
		array_merge(
			$settings,
			$args
		),
		$metadata
	);

	return WP_Block_Type_Registry::get_instance()->register(
		$metadata['name'],
		$settings
	);
}

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Hooks



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Changelog

Changelog
Version Description
6.4.0 Added support for blockHooks field.
6.3.0 Added selectors field.
6.1.0 Added support for render field.
5.9.0 Added support for variations and viewScript fields.
5.7.0 Added support for textdomain field and i18n handling for all translatable fields.
5.5.0 Introduced.

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User Contributed Notes

  1. Skip to note 1 content
    Contributed by mrwweb

    In WordPress 5.8, the ability to use block.json metadata was added to the register_block_type function. Therefore, register_block_type_from_metadata is now redundant and the shorter register_block_type is preferred. The only reason to use register_block_type_from_metadata is for supporting sites on WordPress versions 5.5 – 5.7.

  2. Skip to note 2 content
    Contributed by ztig

    It’s worth noting that when registering blocks using this method, you can not register scripts and styles from block.json if you include it in a theme.

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