5 使用数据存储区
按照文档上的,修改了helloworld.py,保存问候信息和用户信息到数据存储区域:
import cgi
from google.appengine.api import users
from google.appengine.ext import webapp
from google.appengine.ext.webapp.util import run_wsgi_app
from google.appengine.ext import db
class Greeting(db.Model):
author = db.UserProperty()
content = db.StringProperty(multiline=True)
date = db.DateTimeProperty(auto_now_add=True)
class MainPage(webapp.RequestHandler):
def get(self):
self.response.out.write('<html><body>')
#greetings = db.GqlQuery("SELECT * FROM Greeting ORDER BY date DESC LIMIT 10")
#两种写法都可以,下面一种是简写
greetings = Greeting.gql("ORDER BY date DESC LIMIT 10")
for greeting in greetings:
if greeting.author:
self.response.out.write('<b>%s</b> wrote:' % greeting.author.nickname())
else:
self.response.out.write('An anonymous person wrote:')
self.response.out.write('<blockquote>%s</blockquote>' %
cgi.escape(greeting.content))
# Write the submission form and the footer of the page
self.response.out.write("""
<form action="/sign" method="post">
<div><textarea name="content" rows="3" cols="60"></textarea></div>
<div><input type="submit" value="Sign Guestbook"></div>
</form>
</body>
</html>""")
class Guestbook(webapp.RequestHandler):
def post(self):
greeting = Greeting()
if users.get_current_user():
greeting.author = users.get_current_user()
greeting.content = self.request.get('content')
greeting.put()
self.redirect('/')
另外文档上介绍了几个写GQL过滤的方法:
使用位置参数:
if users.get_current_user():
greetings = Greeting.gql("WHERE author = :1 ORDER BY date DESC",
users.get_current_user())
使用命名参数:
greetings = Greeting.gql("WHERE author = :author ORDER BY date DESC",
author=users.get_current_user())
用API filter来查询:
greetings = Greeting.all()
greetings.filter("author =", users.get_current_user())
greetings.order("-date")
6.使用模板
嘿嘿,google使用了类似于django的模板,修改helloworld.py文件如下:
import cgi
import os
from google.appengine.ext.webapp import template
from google.appengine.api import users
from google.appengine.ext import webapp
from google.appengine.ext.webapp.util import run_wsgi_app
from google.appengine.ext import db
class Greeting(db.Model):
author = db.UserProperty()
content = db.StringProperty(multiline=True)
date = db.DateTimeProperty(auto_now_add=True)