serialize_block_attributes() │ WP 5.3.1

Given an array of attributes, returns a string in the serialized attributes format prepared for post content.

The serialized result is a JSON-encoded string, with unicode escape sequence substitution for characters which might otherwise interfere with embedding the result in an HTML comment.

This function must produce output that remains in sync with the output of the serializeAttributes JavaScript function in the block editor in order to ensure consistent operation between PHP and JavaScript.

No Hooks.

Return

String. Serialized attributes.

Usage

serialize_block_attributes( $block_attributes );
$block_attributes(array) (required)
Attributes object.

Changelog

Since 5.3.1 Introduced.

serialize_block_attributes() code WP 6.5.2

wp-includes/blocks.php 
function serialize_block_attributes( $block_attributes ) {
	$encoded_attributes = wp_json_encode( $block_attributes, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE );
	$encoded_attributes = preg_replace( '/--/', '\\u002d\\u002d', $encoded_attributes );
	$encoded_attributes = preg_replace( '/</', '\\u003c', $encoded_attributes );
	$encoded_attributes = preg_replace( '/>/', '\\u003e', $encoded_attributes );
	$encoded_attributes = preg_replace( '/&/', '\\u0026', $encoded_attributes );
	// Regex: /\\"/
	$encoded_attributes = preg_replace( '/\\\\"/', '\\u0022', $encoded_attributes );

	return $encoded_attributes;
}