apply_block_hooks_to_content()WP 6.6.0

Runs the hooked blocks algorithm on the given content.

Internal function — this function is designed to be used by the kernel itself. It is not recommended to use this function in your code.

No Hooks.

Returns

String. The serialized markup.

Usage

apply_block_hooks_to_content( $content, $context, $callback );
$content(string) (required)
Serialized content.
$context(WP_Block_Template|WP_Post|array|null)
A block template, template part, post object, or pattern that the blocks belong to. If set to null, get_post() be called to use the current post as context.
Default: null
$callback(callable)
A function that will be called for each block to generate the markup for a given list of blocks that are hooked to it.
Default: 'insert_hooked_blocks'

Changelog

Since 6.6.0 Introduced.
Since 6.7.0 Injects the theme attribute into Template Part blocks, even if no hooked blocks are registered.
Since 6.8.0 Have the $context parameter default to null, in which case get_post() be called to use the current post as context.

apply_block_hooks_to_content() code WP 6.8.1

function apply_block_hooks_to_content( $content, $context = null, $callback = 'insert_hooked_blocks' ) {
	// Default to the current post if no context is provided.
	if ( null === $context ) {
		$context = get_post();
	}

	$hooked_blocks = get_hooked_blocks();

	$before_block_visitor = '_inject_theme_attribute_in_template_part_block';
	$after_block_visitor  = null;
	if ( ! empty( $hooked_blocks ) || has_filter( 'hooked_block_types' ) ) {
		$before_block_visitor = make_before_block_visitor( $hooked_blocks, $context, $callback );
		$after_block_visitor  = make_after_block_visitor( $hooked_blocks, $context, $callback );
	}

	$block_allows_multiple_instances = array();
	/*
	 * Remove hooked blocks from `$hooked_block_types` if they have `multiple` set to false and
	 * are already present in `$content`.
	 */
	foreach ( $hooked_blocks as $anchor_block_type => $relative_positions ) {
		foreach ( $relative_positions as $relative_position => $hooked_block_types ) {
			foreach ( $hooked_block_types as $index => $hooked_block_type ) {
				$hooked_block_type_definition =
					WP_Block_Type_Registry::get_instance()->get_registered( $hooked_block_type );

				$block_allows_multiple_instances[ $hooked_block_type ] =
					block_has_support( $hooked_block_type_definition, 'multiple', true );

				if (
					! $block_allows_multiple_instances[ $hooked_block_type ] &&
					has_block( $hooked_block_type, $content )
				) {
					unset( $hooked_blocks[ $anchor_block_type ][ $relative_position ][ $index ] );
				}
			}
			if ( empty( $hooked_blocks[ $anchor_block_type ][ $relative_position ] ) ) {
				unset( $hooked_blocks[ $anchor_block_type ][ $relative_position ] );
			}
		}
		if ( empty( $hooked_blocks[ $anchor_block_type ] ) ) {
			unset( $hooked_blocks[ $anchor_block_type ] );
		}
	}

	/*
	 * We also need to cover the case where the hooked block is not present in
	 * `$content` at first and we're allowed to insert it once -- but not again.
	 */
	$suppress_single_instance_blocks = static function ( $hooked_block_types ) use ( &$block_allows_multiple_instances, $content ) {
		static $single_instance_blocks_present_in_content = array();
		foreach ( $hooked_block_types as $index => $hooked_block_type ) {
			if ( ! isset( $block_allows_multiple_instances[ $hooked_block_type ] ) ) {
				$hooked_block_type_definition =
					WP_Block_Type_Registry::get_instance()->get_registered( $hooked_block_type );

				$block_allows_multiple_instances[ $hooked_block_type ] =
					block_has_support( $hooked_block_type_definition, 'multiple', true );
			}

			if ( $block_allows_multiple_instances[ $hooked_block_type ] ) {
				continue;
			}

			// The block doesn't allow multiple instances, so we need to check if it's already present.
			if (
				in_array( $hooked_block_type, $single_instance_blocks_present_in_content, true ) ||
				has_block( $hooked_block_type, $content )
			) {
				unset( $hooked_block_types[ $index ] );
			} else {
				// We can insert the block once, but need to remember not to insert it again.
				$single_instance_blocks_present_in_content[] = $hooked_block_type;
			}
		}
		return $hooked_block_types;
	};
	add_filter( 'hooked_block_types', $suppress_single_instance_blocks, PHP_INT_MAX );
	$content = traverse_and_serialize_blocks(
		parse_blocks( $content ),
		$before_block_visitor,
		$after_block_visitor
	);
	remove_filter( 'hooked_block_types', $suppress_single_instance_blocks, PHP_INT_MAX );

	return $content;
}