def extract_angular(fileobj, keywords, comment_tags, options):
    """Extract messages from angular template (HTML) files.

    It extract messages from angular template (HTML) files that use
    angular-gettext translate directive as per
    https://angular-gettext.rocketeer.be/

    :param fileobj: the file-like object the messages should be extracted
                    from
    :param keywords: This is a standard parameter so it isaccepted but ignored.

    :param comment_tags: This is a standard parameter so it is accepted but
                        ignored.
    :param options: Another standard parameter that is accepted but ignored.
    :return: an iterator over ``(lineno, funcname, message, comments)``
             tuples
    :rtype: ``iterator``
    """

    parser = AngularGettextHTMLParser()

    for line in fileobj:
        parser.feed(encodeutils.safe_decode(line))

    for string in parser.strings:
        yield(string)