tornado框架blog模块分析与使用

　　复制代码 代码如下:
#!/usr/bin/env python
#
# Copyright 2009 Facebook
#
# Licensed under the Apache License, Version 2.0 (the License); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an AS IS BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

　　import markdown
import os.path
import re
import torndb
import tornado.auth
import tornado.httpserver
import tornado.ioloop
import tornado.options
import tornado.web
import unicodedata

　　from tornado.options import define, options
#定义一些通用的配置信息，比如数据库的连接信息，端口信息
define(port, default=8888, help=run on the given port, type=int)
define(mysql_host, default=127.0.0.1:3306, help=blog database host)
define(mysql_database, default=blog, help=blog database name)
define(mysql_user, default=root, help=blog database user)
define(mysql_password, default=sa123, help=blog database password)

　　#定义Application信息，它是继承tornado.web.Application 的
class Application(tornado.web.Application):
# __init__ 函数自动调用
def __init__(self):
#这里就是url对应的控制器，下面分别对应一个类，来处理里面的逻辑
handlers = [
(r/, HomeHandler),
(r/archive, ArchiveHandler),
(r/feed, FeedHandler),
(r/entry/([^/]+), EntryHandler),
(r/compose, ComposeHandler),
(r/auth/login, AuthLoginHandler),
(r/auth/logout, AuthLogoutHandler),
]
#设置，如博客标题，模板目录，静态文件目录，xsrf，是否调试
settings = dict(
blog_title=uTornado Blog,
template_path=os.path.join(os.path.dirname(__file__), templates),
static_path=os.path.join(os.path.dirname(__file__), static),
ui_modules={Entry: EntryModule},
xsrf_cookies=True,
cookie_secret=__TODO:_GENERATE_YOUR_OWN_RANDOM_VALUE_HERE__,
login_url=/auth/login,
debug=True,
)
#然后调用tornado.web.Application类的__init__函数加载进来
tornado.web.Application.__init__(self, handlers, **settings)

　　 # Have one global connection to the blog DB across all handlers
#数据库连接信息
host=options.mysql_host, database=options.mysql_database,
user=options.mysql_user, password=options.mysql_password)

　　#基类，继承自tornado.web.RequestHandler 的，后面的类都是继承这个类的
class BaseHandler(tornado.web.RequestHandler):
#属性装饰器，使db函数变成一个属性，便于后面直接使用
@property
def db(self):
return self.application.db
#获得当前的用户
def get_current_user(self):
user_id = self.get_secure_cookie(blogdemo_user)
if not user_id: return None
return self.db.get(SELECT * FROM authors WHERE id = %s, int(user_id))

　　#首页
class HomeHandler(BaseHandler):
def get(self):
#query 查询很多列
entries = self.db.query(SELECT * FROM entries ORDER BY published
DESC LIMIT 5)
if not entries:
#redirect 重定向到一个url
self.redirect(/compose)
return
#render 渲染一个模板，后面是参数
self.render(home.html, entries=entries)

　　
class EntryHandler(BaseHandler):
def get(self, slug):
#get 得到一个值
entry = self.db.get(SELECT * FROM entries WHERE slug = %s, slug)
#raise 触发一个错误信息，后面必须接类型
if not entry: raise tornado.web.HTTPError(404)
self.render(entry.html, entry=entry)

　　
class ArchiveHandler(BaseHandler):
def get(self):
entries = self.db.query(SELECT * FROM entries ORDER BY published
DESC)
self.render(archive.html, entries=entries)

　　
class FeedHandler(BaseHandler):
def get(self):
entries = self.db.query(SELECT * FROM entries ORDER BY published
DESC LIMIT 10)
self.set_header(Content-Type, application/atom+xml)
self.render(feed.xml, entries=entries)

　　
class ComposeHandler(BaseHandler):
#装饰器
@tornado.web.authenticated
def get(self):
id = self.get_argument(id, None)
entry = None
if id:
entry = self.db.get(SELECT * FROM entries WHERE id = %s, int(id))
self.render(compose.html, entry=entry)

　　 @tornado.web.authenticated
def post(self):
id = self.get_argument(id, None)
title = self.get_argument(title)
text = self.get_argument(markdown)
html = markdown.markdown(text)
if id:
entry = self.db.get(SELECT * FROM entries WHERE id = %s, int(id))
if not entry: raise tornado.web.HTTPError(404)
slug = entry.slug
#execute是执行的意思
self.db.execute(
UPDATE entries SET title = %s, markdown = %s, html = %s
WHERE id = %s, title, text, html, int(id))
else:
slug = unicodedata.normalize(NFKD, title).encode(
ascii, ignore)
slug = re.sub(r[^\w]+, , slug)
slug = -.join(slug.lower().strip().split())
if not slug: slug = entry
while True:
e = self.db.get(SELECT * FROM entries WHERE slug = %s, slug)
if not e: break
slug += -2
self.db.execute(
INSERT INTO entries (author_id,title,slug,markdown,html,
published) VALUES (%s,%s,%s,%s,%s,UTC_TIMESTAMP()),
self.current_user.id, title, slug, text, html)
self.redirect(/entry/ + slug)

　　
class AuthLoginHandler(BaseHandler, tornado.auth.GoogleMixin):
@tornado.web.asynchronous
def get(self):
if self.get_argument(openid.mode, None):
self.get_authenticated_user(self.async_callback(self._on_auth))
return
self.authenticate_redirect()
#这里定义一个函数，来供上面调用
def _on_auth(self, user):
if not user:
raise tornado.web.HTTPError(500, Google auth failed)
author = self.db.get(SELECT * FROM authors WHERE email = %s,
user[email])
if not author:
# Auto-create first author
any_author = self.db.get(SELECT * FROM authors LIMIT 1)
if not any_author:
author_id = self.db.execute(
INSERT INTO authors (email,name) VALUES (%s,%s),
user[email], user[name])
else:
self.redirect(/)
return
else:
author_id = author[id]
self.set_secure_cookie(blogdemo_user, str(author_id))
self.redirect(self.get_argument(next, /))

　　
class AuthLogoutHandler(BaseHandler):
def get(self):
self.clear_cookie(blogdemo_user)
#get_argument为获得next参数的值，默认为/
self.redirect(self.get_argument(next, /))

　　
class EntryModule(tornado.web.UIModule):
def render(self, entry):
return self.render_string(modules/entry.html, entry=entry)

　　#入口函数
def main():
tornado.options.parse_command_line()
#创建一个服务器
http_server = tornado.httpserver.HTTPServer(Application())
#监听端口
http_server.listen(options.port)
#启动服务

　　#调用的入口
if __name__ == __main__:
main()

　　最后总结一下：

　　1）tornado框架中提供的几个demo，都是以这种形式来创建一个应用的
2）对每一个控制器函数，要么是，只可能有2个对外的函数，一个是get，一个是post
3）数据库有3中调用方式，query，get，exec
4）获取参数的值使用 get_argument 函数
5）重定向用redirect 函数
6）所有的函数都是属性这个类的，所有都用self调用
7）渲染模板用render函数