上文的程序中有这样一段：
class MessageHandler(tornado.web.RequestHandler):
def get(self):
self.write('''
<html>
<head>
<title>Please Input Message</title>
</head>
<body>
<form action="/message" method="post">
<input type="text" name="message"><br>
<input type="submit" value="submit">
</form>
</body>
</html>'''
)
def post(self):
#self.set_header("Content-Type", "text/plain")
self.write("You wrote <h1>" + self.get_argument("message") + "</h1>")
当收到GET请求时，返回一段HTML表单。
上面的这种写法，将html写在python代码中，灵活性差，而且view代码与controller代码混合在一块，不符合MVC的原则。
所以我们采用Tornado中的模板。
新建form.html：
<html>
<head>
<title>{{title}}</title>
</head>
<body>
<form action="/message" method="post">
<input type="text" name="message" value="please input.">
<input type="submit" value="submit">
</form>
</body>
</html>
然后将上面的python代码修改为：
class MessageHandler(tornado.web.RequestHandler):
def get(self):
self.render("form.html", title="Input Message")
def post(self):
#self.set_header("Content-Type", "text/plain")
self.write("You wrote <h1>" + self.get_argument("message") + "</h1>")
这样代码简洁了很多。
完整的代码是：
import tornado.ioloop
import tornado.webclass MainHandler(tornado.web.RequestHandler):
def get(self):
self.write("<h1>This is Home Page!</h1>")class StoryHandler(tornado.web.RequestHandler):
def get(self, story_id):
self.write("You request the story <h1>" + story_id + "</h1>")class MessageHandler(tornado.web.RequestHandler):
def get(self):
self.render("form.html", title="Input Message")
def post(self):
#self.set_header("Content-Type", "text/plain")
self.write("You wrote <h1>" + self.get_argument("message") + "</h1>")application = tornado.web.Application([
(r"/", MainHandler),
(r"/story/([0-9]+)", StoryHandler),
(r"/message", MessageHandler),
])if __name__ == '__main__':
application.listen(8888)
tornado.ioloop.IOLoop.instance().start()
