add_filter( 'pre_get_document_title', function( $title ) {
global $post;
if ( ! $post || ! $post->post_content ) {
return $title;
}
if ( preg_match( '#[mc_set_title.*]#', $post->post_content, $matches ) !== 1 ) {
return '';
}
return do_shortcode( $matches[0] );
} );
add_shortcode( 'mc_set_title', function( $atts ) {
if ( ! doing_filter( 'pre_get_document_title' ) ) {
# just remove the shortcode from post content in normal shortcode processing
return '';
}
# in filter 'pre_get_document_title' - you can use $atts and global $post to compute the title
return 'MC TITLE';
} );