]*)>]*)>(.*?)<\/code><\/pre>/s', function ( $matches ) { $pre_attrs = $matches[1]; $code_attrs = $matches[2]; $code = $matches[3]; if ( false === strpos( $pre_attrs, 'language-' ) ) { $pre_attrs .= ' class="language-yaml"'; } if ( false === strpos( $code_attrs, 'language-' ) ) { $code_attrs .= ' class="language-yaml"'; } return sprintf( '
%s
', $pre_attrs, $code_attrs, $code ); }, $content ); return $content; } add_filter( 'the_content', 'ztfr_wrap_code_blocks', 20 );