WordPress at a glance
function is not described

filter_block_kses() WP 5.3.1

Filters and sanitizes a parsed block to remove non-allowable HTML from block attribute values.

No Hooks.

Return

Array. The filtered and sanitized block object result.

Usage

filter_block_kses( $block, $allowed_html, $allowed_protocols );
$block(WP_Block_Parser_Block) (required)
The parsed block object.
$allowed_html(array[]|string) (required)
An array of allowed HTML elements and attributes, or a context name such as 'post'.
$allowed_protocols(string[])
Allowed URL protocols.

Changelog

Since 5.3.1 Introduced.

Code of filter_block_kses() WP 5.7.2

<?php
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 );
		}
	}

	return $block;
}