def METHOD_NAME(root_dir, parent_cmp_type):
    """
    Parses root_dir and return a list of objects of type parent_cmp_type
    for installed extensions. The package objects won't be parsed at this level.
    This is useful for collecting basic info on an extension type
    for cache cheching or updating extensions using their directory paths.
    """
    # making sure the provided directory exists.
    # This is mainly for the user defined package directories
    if not op.exists(root_dir):
        mlogger.debug('Extension search directory does not exist: %s', root_dir)
        return []
    # try creating extensions in given directory
    ext_data_list = []
    mlogger.debug('Parsing directory for extensions of type: %s',
                  parent_cmp_type)
    for ext_data in _create_subcomponents(root_dir, [parent_cmp_type]):
        mlogger.debug('Extension directory found: %s', ext_data)
        ext_data_list.append(ext_data)
    return ext_data_list