In tornado,
- tornado.web.RequestHandler maps URLs to subclasses and
- tornado.web.Application class starts a server at the beginning with certain settings
For instance, in the example below:
- When a HTTP GET request is made to http://127.0.0.1:8888/, class Hello handles it & requests made to http://127.0.0.1:8888/user are catered by class User
- A web form is rendered to the user when the client browses (Http Get) to /user
- When the client fills in the form and clicks on ‘Submit Query’, a HTTP POST request is generated on /user URL
- This request is then served by the post() method of handler class ‘User’ and the message with username and designation is rendered on the browser
Code
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| import tornado.ioloop | |
| import tornado.web | |
| class Hello(tornado.web.RequestHandler): | |
| def get(self): | |
| self.write("Hello, world") | |
| class User(tornado.web.RequestHandler): | |
| def get(self): | |
| form = """<form method="post"> | |
| <input type="text" name="username"/> | |
| <input type="text" name="designation"/> | |
| <input type="submit"/> | |
| </form>""" | |
| self.write(form) | |
| def post(self): | |
| username = self.get_argument('username') | |
| designation = self.get_argument('designation') | |
| self.write("Wow " + username + " you're a " + designation) | |
| application = tornado.web.Application([ | |
| (r"/", Hello), | |
| (r"/user/", User), | |
| ]) | |
| if __name__ == "__main__": | |
| application.listen(8888) | |
| tornado.ioloop.IOLoop.instance().start() |
Form presented to the client
Response from web server
good one and easy to understand thnx