Base64 decoding code block content

base64_decode.php

<?php

add_filter( 'relevanssi_oxygen_section_content', function( $content ) {
	if ( preg_match_all( '/\[ct_code_block.*?ct_code_block\]/', $content, $matches ) ) {
		foreach ( $matches[0] as $match ) {
			if ( preg_match_all( '/"code-php":"(.*?)"/', $match, $block_matches ) ) {
				foreach ( $block_matches[1] as $encoded_text ) {
					$content .= base64_decode( $encoded_text );
				}
			}
		}
	}
	return $content;
});