using_tornado.py

import tornado.ioloop
import tornado.web
import json

# Creates a user
class UserObject:

    def __init__(self, name, username, password):
        self.user = username
        self.passwd = password
        self.name = name

    # instead of creating a big json object 
    # create a class and it will make it for you
    # repetitve task
    def create_user(self):
        return dict(username=self.user, password=self.passwd, name=self.name)

# Need this for cross origin stuff
class BaseHandler(tornado.web.RequestHandler):
    def set_default_headers(self):
        print("setting headers!!!")
        self.set_header("Access-Control-Allow-Origin", "*")
        self.set_header("Access-Control-Allow-Headers", "x-requested-with")
        self.set_header('Access-Control-Allow-Methods', 'POST, GET, OPTIONS')

    # default action if no get is there for a route.
    def get(self):
        self.write('some get')

# What happens @ / or the main page
class MainHandler(BaseHandler):
    def get(self):
        self.write("\n\t/users : get all users\n\t /login: login")

# dumps all the users this is a `GET`
class GetUsers(BaseHandler):
    def get(self):
        self.write(json.dumps(list_of_all_users))

# validates from hard coded users
# if username and password are correct it returns the userinfo
class Login(BaseHandler):
    def post(self):
        args = json.loads(self.request.body)
        try:
            for user in list_of_all_users['users']:
                if args['user'] == user['username'] and args['passwd'] == user['password']:
                    self.write(user)
        except:
            self.write(dict(error="user not found, please check your credentials"))


def make_app():
    # tie the functions with the route
    return tornado.web.Application([
        (r"/", MainHandler),
        (r"/users", GetUsers),
        (r"/login", Login),
    ])

if __name__ == "__main__":
    # create users start
    big_bro = UserObject(name="Paramjit", username="pj123", password="123").create_user()
    me = UserObject(name="Jasmit", username="jt123", password="123").create_user()
    # creat users end
    list_of_all_users = dict(users=[big_bro, me]) # group users in a json object
    app = make_app() # start the server
    app.listen(8888) # uses port 8888
    # tries to start the server
    try:
        tornado.ioloop.IOLoop.current().start()
    # if something is wrong or ctrl + c is pressed it stops
    except:
        tornado.ioloop.IOLoop.current().stop()