Live coding

gistfile1.py

# -*- coding: utf-8 -*-
import os
import datetime
import jinja2
import webapp2
from google.appengine.api import users
from google.appengine.ext import ndb

class Page(ndb.Model):
  title = ndb.StringProperty(indexed=False)
  body = ndb.StringProperty(indexed=False)
  user_id = ndb.StringProperty(indexed=False)
  updated = ndb.DateTimeProperty(indexed=True)
  created = ndb.DateTimeProperty(indexed=False)
  
  @property
  def id(self):
    return self.key.id()

class BaseHandler(webapp2.RequestHandler):
  def render(self, _template_name, **kwds):
    kwds.setdefault("params", self.request.params)
    t = Jinja2.get_template(_template_name)
    s = t.render(**kwds)
    self.response.headers["Content-Type"] = "text/html; charset=UTF-8"
    self.response.write(s)

class MainHandler(BaseHandler):
  def get(self):
    q = Page.query()
    q.order(-Page.updated)
    pages = q.fetch(10)
    self.render("list.html", pages=pages)

class PageShowHandler(BaseHandler):
  def get(self, num):
    page = Page.get_by_id(int(num))
    self.render("show.html", page=page)

class BasePageEditHandler(BaseHandler):
  def get_values(self):
    title = self.request.get("title")
    body = self.request.get("body")
    if not title:
      raise ValueError(u"タイトルを入力してください")
    if len(title) > 10:
      raise ValueError(u"タイトルは10文字以下にしてください")
    if not body:
      raise ValueError(u"本文を入力してください")
    if len(body) > 140:
      raise ValueError(u"本文は140文字以下にしてください")
    return title, body

class PageCreateHandler(BasePageEditHandler):
  def get(self):
    self.render("create.html")
  
  def post(self):
    try:
      title, body = self.get_values()
    except ValueError as ex:
      self.render("create.html", error=ex.message)
      return
    
    now = datetime.datetime.utcnow()
    page = Page(
      title=title,
      body=body,
      updated=now,
      created=now,
      )
    key = page.put()
    self.redirect("/page/" + str(key.id()))

class PageEditHandler(BasePageEditHandler):
  def get(self, num):
    page = Page.get_by_id(int(num))
    self.render("edit.html", page=page)
  
  def post(self, num):
    page = Page.get_by_id(int(num))
    try:
      title, body = self.get_values()
    except ValueError as ex:
      self.render("edit.html", error=ex.message)
      return
    now = datetime.datetime.utcnow()
    page.title = title
    page.body = body
    page.updated = now
    page.put()
    self.redirect("/page/" + num)

app = webapp2.WSGIApplication([
  ("/", MainHandler),
  ("/page/(\d+)", PageShowHandler),
  ("/edit/(\d+)", PageEditHandler),
  ("/create", PageCreateHandler),
], debug=True)

Jinja2 = jinja2.Environment(
  loader=jinja2.FileSystemLoader(
    os.path.join(os.path.dirname(__file__), "templates")),
  extensions=['jinja2.ext.autoescape'],
  autoescape=True)