public static function get_undeletable_block_types() {
        global $CFG;
        $undeletableblocks = false;
        if (isset($CFG->undeletableblocktypes)) {
            $undeletableblocks = $CFG->undeletableblocktypes;
        }

        if (empty($undeletableblocks)) {
            return array();
        } else if (is_string($undeletableblocks)) {
            return explode(',', $undeletableblocks);
        } else {
            return $undeletableblocks;
        }
    }
public static function get_undeletable_block_types() {
        global $CFG;
        $undeletableblocks = false;
        if (isset($CFG->undeletableblocktypes)) {
            $undeletableblocks = $CFG->undeletableblocktypes;
        }

        if (empty($undeletableblocks)) {
            return array();
        } else if (is_string($undeletableblocks)) {
            return explode(',', $undeletableblocks);
        } else {
            return $undeletableblocks;
        }
    }
public static function get_undeletable_block_types ( ) { global $ CFG ; $ undeletableblocks = false ; if ( isset ( $ CFG -> undeletableblocktypes ) ) { $ undeletableblocks = $ CFG -> undeletableblocktypes ; } if ( empty ( $ undeletableblocks ) ) { return array ( ) ; } else if ( is_string ( $ undeletableblocks ) ) { return explode ( ',' , $ undeletableblocks ) ; } else { return $ undeletableblocks ; } }
Get the list of "protected" blocks via admin block manager ui.

@return array names of block types that cannot be added or deleted. E.g. array('navigation','settings').
Get the list of protected blocks via admin block manager ui .