Untitled

import webapp2

import cgi

import codecs

import re


def escape_html(s):
    return cgi.escape(s, quote = True)

signup_form = """ <html>
  <head>

    <title>Signup</title>
    <style type='text/css'>
      .label {
        text-align: right;
      }
      .error {
        color: red;
      }
    </style>

<h2>Signup</h2>

<form method="post">

   <br>
   <table>

    <tr>
      <label>
       Name
    </label>
    <td>
       <input type="text" name="username" value="%(username)s">
    </td>
    <td class="error">
       %(username_error)s
    <td>
  </tr>

  <tr>
    <label>
      Password
    </label>
    <td>
      <input type="text" name="password" value="%(password)s">
    </td>
    <td class="error">
       %(password_error)s
    <td>
  </tr>

  <tr>
     <label>
        Verify Password
     </label>
     <td>
        <input type="text" name="verify" value="%(verify)s">
     </td>
     <td class="error">
       %(verify_error)s
    <td>
  </tr>

  <tr>
     <label>
        Email
     </label>
     <td>
        <input type="text" name="email" value="%(email)s">
     </td>
     <td class="error">
       %(email_error)s
    <td>
  </tr>


   <input type="submit">

</form>
"""

USER_RE = re.compile(r"^[a-zA-Z0-9_-]{3,20}$")
PASSWORD_RE = re.compile(r"^.{3,20}$")
EMAIL_RE = re.compile(r"^[\S]+@[\S]+\.[\S]+$")


def valid_username(username):
  return USER_RE.match(username)

def valid_password(password):
  return PASSWORD_RE.match(password)

def valid_email(email):
  return EMAIL_RE.match(email)


class MainHandler(webapp2.RequestHandler):

    def write_signup(self, username="", password="", verify="", email="", username_error="", password_error="", verify_error="", email_error=""):
        self.response.out.write(signup_form % {"username": username,
                             "password": "",
                             "verify": "",
                             "email": email,
                             "username_error": username_error,
                             "password_error": password_error,
                             "verify_error": verify_error,
                             "email_error": email_error
                             })

    def get(self):
        self.write_signup()

    def post(self):

        username = self.request.get('username')
        password = self.request.get('password')
        verify = self.request.get('verify')
        email = self.request.get('email')

        username = valid_username(username)
        password = valid_password(password)
        verify = valid_password(verify)
        email = valid_email(email)


        if (valid_username(username) and valid_password(password) and valid_email(email) and (password == verify)):
            self.redirect('/welcome?username=' + username)

        else:
            if not valid_username(username):
                username_error = "Invalid Username"
            if not valid_password(password):
                password_error = "Invalid Password"
            if password != verify:
                verify_error = "Passwords don't match!"
            if not valid_email(email):
                email_error = "Invalid Email"
            self.write_form(username, password, verify, email, username_error, password_error, verify_error, email_error)


class WelcomeHandler(webapp2.RequestHandler):

  def write_welcome(self, username=""):
    self.response.out.write("Welcome, %s" % username)

  def get(self):
    self.write_welcome(self.request.get('username'))


app = webapp2.WSGIApplication([
                               ('/', MainHandler), ('/welcome', WelcomeHandler)
                               ], debug=True)