def robotsrulesetOfDomain(self, domain):
		'''检查domain是否在数据库中,
			否 --> (False, None)
			是 --> (True, 数据库中存储的robots.txt内容)
		'''
		exist = False
		cur = self.conn.cursor()
		# 是否存在
		cur.execute("SELECT 1 FROM Domains WHERE domain=?", (domain,))
		if cur.fetchone() :
			exist = True
		# 存在的话,结果是什么
		cur.execute("SELECT rules FROM Domains,Rulesets "
			"WHERE domain=? AND Domains.did=Rulesets.did"
			,(domain,) )
		ruleset = cur.fetchone()
		return (exist, ruleset)
def __init__(self, reddit, term, config, oauth, url=None, submission=None):
        super(SubmissionPage, self).__init__(reddit, term, config, oauth)

        self.controller = SubmissionController(self, keymap=config.keymap)

        if url:
            self.content = SubmissionContent.from_url(
                reddit, url, term.loader,
                max_comment_cols=config['max_comment_cols'])
        else:
            self.content = SubmissionContent(
                submission, term.loader,
                max_comment_cols=config['max_comment_cols'])
        # Start at the submission post, which is indexed as -1
        self.nav = Navigator(self.content.get, page_index=-1)
        self.selected_subreddit = None