Extract messages from angular template (HTML) files that use the
    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 is accepted 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``

    This particular extractor is quite simple because it is intended to only
    deal with angular templates which do not need comments, or the more
    complicated forms of translations.

    A later version will address pluralization.

def extract_angular(fileobj, keywords, comment_tags, options):
    """Extract messages from angular template (HTML) files that use the
    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 is accepted 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``

    This particular extractor is quite simple because it is intended to only
    deal with angular templates which do not need comments, or the more
    complicated forms of translations.

    A later version will address pluralization.
    """

    if keywords:
        logging.debug('Parameter keywords ignored.')

    if comment_tags:
        logging.debug('Parameter comment_tags ignored.')

    if options:
        logging.debug('Parameter options ignored.')

    parser = AngularGettextHTMLParser()

    for line in fileobj:
        if not isinstance(line, str):
            line = line.decode(locale.getpreferredencoding())
        parser.feed(line)

    for string in parser.strings:
        yield(string)