gae session & ajax & ndb usage example


Session ajax
gae python post form tutorial


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http://olivecodex.blogspot.in/2013/09/ajax-with-jquery-and-google-app-engine.html?m=1


Navigate to localhost/static.html

static.html to something we can manipulate:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
       <meta http-equiv="Content-type" content="text/html; charset=utf-8" />
       <title>Ajax With Jquery</title>

       <!-- Grab the JQuery API from the Google servers -->
       <script src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js" type="text/javascript" charset="utf-8"></script>

       <!-- Our own JQuery code to do the AJAX-y stuff -->
       <script type="text/javascript" charset="utf-8">
       $(document).ready(function(){
            // This will run when the item of class 'button' is clicked
            $(".button").click(function() {

                // Grabs the text input
                var name = $("input#txtValue").val();

                var dataString = 'txtValue='+ name;
                // This creates the AJAX connection
                $.ajax({
                    type: "POST",
                    url: "/tutorial",
                    data: dataString,
                    success: function(data) {
                        $('#display').html(data.text);
                    }
                });
            return false;
            });
        });
       </script>
    </head>

    <body>
         <form name="contact" method="post" action="">
            <label for="txtValue">Enter a value : </label>
            <input type="text" name="txtValue" value="" id="txtValue">
            <input type="submit" name="submit" class="button" id="submit_btn" value="Send" />
         </form>
         <div id="display">
         </div>
   </body>
</html>

Our JavaScript now sends some data to an external URL (in this case /tutorial) and inserts the returned data into the display div. Now all we need to do is code our Python script....

Our Python webapp
Create a file called tutorial.py and add the following code:

# The webapp2 framework
import webapp2

# The JSON library
import json

# Our JSON handler class
class JsonPage(webapp2.RequestHandler):
    # The POST handler
    def post(self):
        # Our POST Input
        txtinput = self.request.get('txtValue')

        # Create an array
        array = {'text': txtinput}

        # Output the JSON
        self.response.headers['Content-Type'] = 'application/json'
        self.response.out.write(json.dumps(array))

# URL map the JSON function
app = webapp2.WSGIApplication([('/tutorial', JsonPage)], debug=True)

Now we just need to edit app.yaml so it can serve up our tutorial script:

application: almightynassar
version: 1
runtime: python27
api_version: 1
threadsafe: no

handlers:
- url: /(.*).html
  static_files: \1.html
  upload: (.*).html

- url: /(.*)
  script: tutorial.app


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http://www.brianbolton.me/2012/11/20/Basic-CRUD-app-for-Python-and-Google-App-Engine.html


Basic CRUD app for Python and Google App Engine
20 Nov 2012

I wrote a very basic CRUD app for Google App Engine in Python. It's a basic sample on how to add, edit, delete, and list a single entity in GAE. I didn't see anything like this on the web when I was learning GAE. I hope this helps you.

You need python 2.7 installed and Google App Engine installed to get up and running. I ran into one issue on Windows where nothing worked until I specified the version of python in GAE. I didn't have this issue on Mac OS X.

basiccrud.py
import webapp2
import cgi
import datetime
import urllib

from google.appengine.ext import db
from google.appengine.api import users

#blog###################################################
class BlogPost(db.Model):
    title = db.StringProperty()
    content = db.StringProperty()
    date = db.DateTimeProperty(autonowadd=True)

def BlogPostKey():
    return db.Key.frompath('Blog','defaultblog')

def BlogById(id):
    return BlogPost.getbyid(id,parent=BlogPostKey())


#PAGES#################################################
class MainPage(webapp2.RequestHandler):
    def get(self):
        self.response.write(
            '<html>'
                '<body>'
                    '<a href="/AddPost">AddPost</a>')

        BlogPosts = db.GqlQuery("select * from BlogPost order by date desc limit 10")

        self.response.write('<ul>')

        for post in BlogPosts:
            self.response.write('<li>{title} at {date} key: ' \
            '{key}<a href="/EditPost?id={key}">Edit</a></li>'
                .format(title=post.title,date=post.date,key=post.key().id()))

        self.response.write('</ul>')
        self.response.write('</body></html>')


class AddPost(webapp2.RequestHandler):
    def get(self):
        self.response.write(
            '<html>'
                '<body>'
                '<form action="/AddPost" method="POST">'
                    'TITLE:<input type=text name=title value=""/>'
                    '<br>CONTENT:<input type=text name=content value=""/>'
                    '<br><input type=submit text="submit"/>'
                '</form>'
                '</body>'
            '</html>')
    def post(self):
        title = self.request.get('title')
        content = self.request.get('content')
        newpost = BlogPost(parent=BlogPostKey())
        newpost.title = title
        newpost.content = content
        newpost.put()
        self.redirect('/')

class EditPost(webapp2.RequestHandler):
    def get(self):
        id = int(self.request.get('id'))
        newpost = BlogById(id)
        self.response.write(
            '<html>'
                '<body>'
                '<form action="/EditPost" method="POST">'
                    '<input type="hidden" value="{id}" name="id">'
                    'TITLE:<input type=text name=title value="{title}"/>'
                    '<br>CONTENT:<input type=text name=content value="{content}"/>'
                    '<br><input type=submit value="Save"/>'
                '</form>'
                '<form action="/DeletePost" method="POST">'
                    '<input type="hidden" value="{id}" name="id">'
                    '<br><input type=submit value="delete"/>'
                '</form>'
                '</body>'
            '</html>'
            .format(title=newpost.title,
                content=newpost.content,id=newpost.key().id()))
    def post(self):
        title = self.request.get('title')
        content = self.request.get('content')
        id = int(self.request.get('id'))
        newpost = BlogById(id)
        newpost.title = title
        newpost.content = content
        newpost.put()
        self.redirect('/')

class DeletePost(webapp2.RequestHandler):
    def post(self):
        id = int(self.request.get('id'))
        newpost = BlogById(id)
        newpost.delete()
        self.redirect('/')


app = webapp2.WSGIApplication([('/', MainPage),
                                ('/AddPost',AddPost),
                                ('/EditPost',EditPost),
                                ('/DeletePost',DeletePost)],
                              debug=True)
app.yaml
application: basiccrud
version: 1
runtime: python27
api_version: 1
threadsafe: true

handlers:
- url: /.*
  script: basiccrud.app

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http://www.manejandodatos.es/2016/01/google-app-engine-with-python-webapp2-in-action/

Create a configuration file, called appengine_config.py, with this code:


from gaesessions import SessionsMiddleware

from gaesessions import
def webapp_add_wagi_middleware(app):
app = SessionsMiddleware(app, cookie_key="qwertywewaawasdpdfsdfkllddlkeerrer")
return app


First, let’s store some info in the session variable by calling the post method. Now, We can add the restriction of having at least 5 characters, and if not, a message will be shown:


def post(self):
    session = get_current_session()
    count = session[self.contador]
    nombre = self.request.get("nombre")
    # Guardo la info en Sesion
    session[self.nombre] = nombre
    session[self.mens] = ''
    if len(nombre) < 5:
        session[self.mens] = 'Nombre demasiado corto!'
        self.redirect(root)
    mensaje = ('Hola ... %s, Has entrado %d veces' % (nombre, count))
    self.response.out.write(mensaje)
    session[self.contador] = 0


#For retrieving this info, you need to use the get method:


def get(self):
    session = get_current_session()
    nombre = session.get(self.nombre, '')
    count = session.get(self.contador) + 1
    session[self.contador] = count
    self.response.write(html % (count, nombre))


#!/usr/bin/env python
#   Manejandodatos.es
#   Probando Google App Engine con Python
#
import webapp2
from gaesessions import get_current_session
import cgi

root = '/'
html = """
<html lang="es">
<head><title>Probando Google App Engine for Python</title></head>
<body>
<h1>Probando Google App Engine for Python</h1>
Cargado %d veces %s
<form method="post">
<label for="nombre">Nombre</label>
<input name="nombre" id="nombre" type="text" value="%s" />
<input type="submit" value="Enviar">
</form>
</body>
</html>
"""

class MainHandler(webapp2.RequestHandler):
contador = 'count'
nombre = 'nombre'
mens = 'mensaje'
def post(self):
session = get_current_session()
count = session[self.contador]
nombre = self.request.get("nombre")
# Guardo la info en Sesion
session[self.nombre] = nombre
if len(nombre) < 5:
session[self.mens] = 'Nombre demasiado corto!'
self.redirect(root)
mensaje = ('Hola ... %s, Has entrado %d veces' % (nombre, count))
self.response.out.write(mensaje)
session[self.contador] = 0

def get(self):
session = get_current_session()
nombre = cgi.escape(session.get(self.nombre, ''), quote=True)
count = session.get(self.contador, 0) + 1 # El contador es INTERNO y no necesita control de ESCAPE
session[self.contador] = count
mensaje = cgi.escape(session.get(self.mens, ''), quote=True)
self.response.write(html % (count, mensaje, nombre))

app = webapp2.WSGIApplication([(root, MainHandler)], debug=True)


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