Detailed explanation of python using decorator to automatically register Tornado routing

First version

In this version, the RouterConfig object is first created, and its constructor creates tornado.web.Application() and assigns a value For self.Application, add the @app.route decorator on each Handler, which corresponds to the route object under RouterConfig, in which the Handler instance will be assigned to the handler parameter. Finally, the corresponding relationship between URL and Handler is added to the routing table, and the URL attribute is created in each Handler.

#!/usr/bin/env python
# _*_ coding:utf-8 _*_

# Created by 安生 on 2017/2/9

import tornado
import tornado.web
import tornado.ioloop

class RouterConfig:
 def __init__(self):
  self.Application = tornado.web.Application() # 创建路由对象

 def route(self, handler):
  self.Application.add_handlers('.*$', [(handler.URL, handler)]) # 路有关系映射添加到路由表中

app = RouterConfig() # 创建路由

@app.route
class MainHandler(tornado.web.RequestHandler):
 URL = r'/'

 def get(self, *args, **kwargs):
  self.write('Hello, 安生')

@app.route
class MainHandler(tornado.web.RequestHandler):
 URL = r'/hi'

 def get(self, *args, **kwargs):
  self.write('hi, 安生')

if __name__ == "__main__":
 app.Application.listen(8000)
 print("http://127.0.0.1:8000/")
 tornado.ioloop.IOLoop.instance().start()

Second version

Create a Route object, and then add a decorator to the Handler @route(r'/') , and pass in the URL, which corresponds to the url parameter in the __call__ method, and then add the route correspondence to the list in the form of ancestors , after all routes have been added, create the Tornado route object, then put the routing table into it, and finally complete the registration.

#!/usr/bin/env python
# _*_ coding:utf-8 _*_

# Created by 安生 on 2017/2/9

import tornado.ioloop
import tornado.web

class Route(object):
 """ 把每个URL与Handler的关系保存到一个元组中，然后追加到列表内，列表内包含了所有的Handler """

 def __init__(self):
  self.urls = list() # 路由列表

 def __call__(self, url, *args, **kwargs):
  def register(cls):
   self.urls.append((url, cls)) # 把路由的对应关系表添加到路由列表中
   return cls

  return register

route = Route() # 创建路由表对象

@route(r'/')
class MainHandler(tornado.web.RequestHandler):
 def get(self, *args, **kwargs):
  self.write('Hello, 安生')

@route(r'/hi')
class MainHandler(tornado.web.RequestHandler):
 def get(self, *args, **kwargs):
  self.write('hi, 安生')

application = tornado.web.Application(route.urls) # 创建app，并且把路有关系放入到Application对象中

if __name__ == '__main__':
 application.listen(8000)
 print("http://127.0.0.1:%s/" % 8000)
 tornado.ioloop.IOLoop.instance().start()

The third version

This version is also the version I am using now, the principles are the same , the feature here is to inherit the Tornado routing object

#!/usr/bin/env python
# _*_ coding:utf-8 _*_

# Created by 安生 on 2017/2/9

import tornado.web
import tornado.ioloop

class RouterConfig(tornado.web.Application):
 """ 重置Tornado自带的路有对象 """

 def route(self, url):
  """
  :param url: URL地址
  :return: 注册路由关系对应表的装饰器
  """

  def register(handler):
   """
   :param handler: URL对应的Handler
   :return: Handler
   """
   self.add_handlers(".*$", [(url, handler)]) # URL和Handler对应关系添加到路由表中
   return handler

  return register

app = RouterConfig(cookie_secret='ulb7bEIZmwpV545Z') # 创建Tornado路由对象，默认路由表为空

@app.route(r'/')
class MainHandler(tornado.web.RequestHandler):
 def get(self, *args, **kwargs):
  self.write('Hello, 安生')

@app.route(r'/hi')
class MainHandler(tornado.web.RequestHandler):
 def get(self, *args, **kwargs):
  self.write('hi, 安生')

if __name__ == "__main__":
 app.listen(8000)
 print("http://127.0.0.1:%s/" % 8000)
 tornado.ioloop.IOLoop.instance().start()

Test

In the above version, test The method and output are the same. You can use the requests module to simulate HTTP requests

>>> import requests
>>> requests.get('http://127.0.0.1:8000/').text
'Hello, 安生'
>>> requests.get('http://127.0.0.1:8000/hi').text
'hi, 安生'

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