* Returns the content of a block, including comment delimiters, serializing all
* attributes from the given parsed block.
* This should be used when preparing a block to be saved to post content.
* Prefer `render_block` when preparing a block for display. Unlike
* `render_block`, this does not evaluate a block's `render_callback`, and will
* instead preserve the markup as parsed.
* @param WP_Block_Parser_Block $block A single parsed block object.
* @return string String of rendered HTML.
function serialize_block( $block ) {
foreach ( $block['innerContent'] as $chunk ) {
$block_content .= is_string( $chunk ) ? $chunk : serialize_block( $block['innerBlocks'][ $index++ ] );
if ( ! is_array( $block['attrs'] ) ) {
$block['attrs'] = array();
return get_comment_delimited_block_content(
* Returns a joined string of the aggregate serialization of the given parsed
* @param WP_Block_Parser_Block[] $blocks Parsed block objects.
* @return string String of rendered HTML.
function serialize_blocks( $blocks ) {
return implode( '', array_map( 'serialize_block', $blocks ) );
* Filters and sanitizes block content to remove non-allowable HTML from
* parsed block attribute values.
* @param string $text Text that may contain block content.
* @param array[]|string $allowed_html An array of allowed HTML elements
* and attributes, or a context name
* @param string[] $allowed_protocols Array of allowed URL protocols.
* @return string The filtered and sanitized content result.
function filter_block_content( $text, $allowed_html = 'post', $allowed_protocols = array() ) {
if ( false !== strpos( $text, '<!--' ) && false !== strpos( $text, '--->' ) ) {
$text = preg_replace_callback( '%<!--(.*?)--->%', '_filter_block_content_callback', $text );
$blocks = parse_blocks( $text );
foreach ( $blocks as $block ) {
$block = filter_block_kses( $block, $allowed_html, $allowed_protocols );
$result .= serialize_block( $block );
* Callback used for regular expression replacement in filter_block_content().
* @param array $matches Array of preg_replace_callback matches.
* @return string Replacement string.
function _filter_block_content_callback( $matches ) {
return '<!--' . rtrim( $matches[1], '-' ) . '-->';
* Filters and sanitizes a parsed block to remove non-allowable HTML from block
* @param WP_Block_Parser_Block $block The parsed block object.
* @param array[]|string $allowed_html An array of allowed HTML
* elements and attributes, or a
* context name such as 'post'.
* @param string[] $allowed_protocols Allowed URL protocols.
* @return array The filtered and sanitized block object result.
function filter_block_kses( $block, $allowed_html, $allowed_protocols = array() ) {
$block['attrs'] = filter_block_kses_value( $block['attrs'], $allowed_html, $allowed_protocols );
if ( is_array( $block['innerBlocks'] ) ) {
foreach ( $block['innerBlocks'] as $i => $inner_block ) {
$block['innerBlocks'][ $i ] = filter_block_kses( $inner_block, $allowed_html, $allowed_protocols );
* Filters and sanitizes a parsed block attribute value to remove non-allowable
* @param string[]|string $value The attribute value to filter.
* @param array[]|string $allowed_html An array of allowed HTML elements
* and attributes, or a context name
* @param string[] $allowed_protocols Array of allowed URL protocols.
* @return string[]|string The filtered and sanitized result.
function filter_block_kses_value( $value, $allowed_html, $allowed_protocols = array() ) {
if ( is_array( $value ) ) {
foreach ( $value as $key => $inner_value ) {
$filtered_key = filter_block_kses_value( $key, $allowed_html, $allowed_protocols );
$filtered_value = filter_block_kses_value( $inner_value, $allowed_html, $allowed_protocols );
if ( $filtered_key !== $key ) {
$value[ $filtered_key ] = $filtered_value;
} elseif ( is_string( $value ) ) {
return wp_kses( $value, $allowed_html, $allowed_protocols );
* Parses blocks out of a content string, and renders those appropriate for the excerpt.
* As the excerpt should be a small string of text relevant to the full post content,
* this function renders the blocks that are most likely to contain such text.
* @param string $content The content to parse.
* @return string The parsed and filtered content.
function excerpt_remove_blocks( $content ) {
$allowed_inner_blocks = array(
// Classic blocks have their blockName set to null.
$allowed_blocks = array_merge( $allowed_inner_blocks, array( 'core/columns' ) );
* Filters the list of blocks that can contribute to the excerpt.
* If a dynamic block is added to this list, it must not generate another
* excerpt, as this will cause an infinite loop to occur.
* @param array $allowed_blocks The list of allowed blocks.
$allowed_blocks = apply_filters( 'excerpt_allowed_blocks', $allowed_blocks );
$blocks = parse_blocks( $content );
foreach ( $blocks as $block ) {
if ( in_array( $block['blockName'], $allowed_blocks, true ) ) {
if ( ! empty( $block['innerBlocks'] ) ) {
if ( 'core/columns' === $block['blockName'] ) {
$output .= _excerpt_render_inner_columns_blocks( $block, $allowed_inner_blocks );
// Skip the block if it has disallowed or nested inner blocks.
foreach ( $block['innerBlocks'] as $inner_block ) {
! in_array( $inner_block['blockName'], $allowed_inner_blocks, true ) ||
! empty( $inner_block['innerBlocks'] )
$output .= render_block( $block );
* Render inner blocks from the `core/columns` block for generating an excerpt.
* @param array $columns The parsed columns block.
* @param array $allowed_blocks The list of allowed inner blocks.
* @return string The rendered inner blocks.
function _excerpt_render_inner_columns_blocks( $columns, $allowed_blocks ) {
foreach ( $columns['innerBlocks'] as $column ) {
foreach ( $column['innerBlocks'] as $inner_block ) {
if ( in_array( $inner_block['blockName'], $allowed_blocks, true ) && empty( $inner_block['innerBlocks'] ) ) {
$output .= render_block( $inner_block );
* Renders a single block into a HTML string.
* @global WP_Post $post The post to edit.
* @global WP_Query $wp_query WordPress Query object.
* @param array $parsed_block A single parsed block object.
* @return string String of rendered HTML.
function render_block( $parsed_block ) {
* Allows render_block() to be short-circuited, by returning a non-null value.
* @param string|null $pre_render The pre-rendered content. Default null.
* @param array $parsed_block The block being rendered.
$pre_render = apply_filters( 'pre_render_block', null, $parsed_block );
if ( ! is_null( $pre_render ) ) {
$source_block = $parsed_block;
* Filters the block being rendered in render_block(), before it's processed.
* @param array $parsed_block The block being rendered.
* @param array $source_block An un-modified copy of $parsed_block, as it appeared in the source content.
$parsed_block = apply_filters( 'render_block_data', $parsed_block, $source_block );
if ( $post instanceof WP_Post ) {
$context['postId'] = $post->ID;
* The `postType` context is largely unnecessary server-side, since the ID
* is usually sufficient on its own. That being said, since a block's
* manifest is expected to be shared between the server and the client,
* it should be included to consistently fulfill the expectation.
$context['postType'] = $post->post_type;
if ( $wp_query instanceof WP_Query && isset( $wp_query->tax_query->queried_terms['category'] ) ) {
$context['query'] = array( 'categoryIds' => array() );
foreach ( $wp_query->tax_query->queried_terms['category']['terms'] as $category_slug_or_id ) {
$context['query']['categoryIds'][] = 'slug' === $wp_query->tax_query->queried_terms['category']['field'] ? get_cat_ID( $category_slug_or_id ) : $category_slug_or_id;
* Filters the default context provided to a rendered block.
* @param array $context Default context.
* @param array $parsed_block Block being rendered, filtered by `render_block_data`.
$context = apply_filters( 'render_block_context', $context, $parsed_block );
$block = new WP_Block( $parsed_block, $context );
* Parses blocks out of a content string.
* @param string $content Post content.
* @return array[] Array of parsed block objects.
function parse_blocks( $content ) {
* Filter to allow plugins to replace the server-side block parser
* @param string $parser_class Name of block parser class.
$parser_class = apply_filters( 'block_parser_class', 'WP_Block_Parser' );
$parser = new $parser_class();
return $parser->parse( $content );
* Parses dynamic blocks out of `post_content` and re-renders them.
* @param string $content Post content.
* @return string Updated post content.
function do_blocks( $content ) {
$blocks = parse_blocks( $content );
foreach ( $blocks as $block ) {
$output .= render_block( $block );
// If there are blocks in this content, we shouldn't run wpautop() on it later.
$priority = has_filter( 'the_content', 'wpautop' );
if ( false !== $priority && doing_filter( 'the_content' ) && has_blocks( $content ) ) {
remove_filter( 'the_content', 'wpautop', $priority );
add_filter( 'the_content', '_restore_wpautop_hook', $priority + 1 );
* If do_blocks() needs to remove wpautop() from the `the_content` filter, this re-adds it afterwards,
* for subsequent `the_content` usage.
* @param string $content The post content running through this filter.
* @return string The unmodified content.
function _restore_wpautop_hook( $content ) {
$current_priority = has_filter( 'the_content', '_restore_wpautop_hook' );
add_filter( 'the_content', 'wpautop', $current_priority - 1 );
remove_filter( 'the_content', '_restore_wpautop_hook', $current_priority );
* Returns the current version of the block format that the content string is using.
* If the string doesn't contain blocks, it returns 0.
* @param string $content Content to test.
* @return int The block format version is 1 if the content contains one or more blocks, 0 otherwise.
function block_version( $content ) {
return has_blocks( $content ) ? 1 : 0;
* Registers a new block style.
* @param string $block_name Block type name including namespace.
* @param array $style_properties Array containing the properties of the style name,
* label, style (name of the stylesheet to be enqueued),
* inline_style (string containing the CSS to be added).
* @return bool True if the block style was registered with success and false otherwise.
function register_block_style( $block_name, $style_properties ) {
return WP_Block_Styles_Registry::get_instance()->register( $block_name, $style_properties );
* Unregisters a block style.
* @param string $block_name Block type name including namespace.
* @param array $block_style_name Block style name.
* @return bool True if the block style was unregistered with success and false otherwise.
function unregister_block_style( $block_name, $block_style_name ) {
return WP_Block_Styles_Registry::get_instance()->unregister( $block_name, $block_style_name );
It is recommended that you Edit text format, this type of Fix handles quite a lot in one request
