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
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# 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=u\”Tornado 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
        self.db = torndb.Connection(
            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
    tornado.ioloop.IOLoop.instance().start()

#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