Skip to main content

Facebook App


Well I thought I would have a crack at making a facebook application last weekend.
Figured although theres no official python facebook api there were a few third party options so I might as well use my favorite language...

I also decided that it would also be a nice opportunity to look at this Django framework thing...

I also decided that it might as well run on Google's Appengine...

So first I skimmed through the django tutorial again - I've only used django once before and that was just a quick look to get graphs from Matplotlib displayed on a webpage.

Then I took my time going through the appengine tutorial.... There are a few things that you have to get used too in switching from django to appengine. The easiest but also most annoying is changing all the models to use Google db models.

Once I was reasonably to grips with both engines I started the fun bit of getting a django app running on app engine. It is actually easy as! My mechanical engineering friend Jun is keen to help out, so I have set up a bzr repository, and a shared appengine application.




Since facebook api is sweet, and I noticed a small wee site called Digg using it - I then decided to integrate facebook connect into my alpha uccc site on appengine, thats so remarkably easy I can't wait to find time to get the actual site using facebook connect instead of yet another username/password combination.

Popular posts from this blog

Bluetooth with Python 3.3

Since about version 3.3 Python supports Bluetooth sockets natively. To put this to the test I got hold of an iRacer from sparkfun . To send to New Zealand the cost was $60. The toy has an on-board Bluetooth radio that supports the RFCOMM transport protocol. The drive  protocol is dead easy, you send single byte instructions when a direction or speed change is required. The bytes are broken into two nibbles:  0xXY  where X is the direction and Y is the speed. For example the byte 0x16 means forwards at mid-speed. I was surprised to note the car continues carrying out the last given demand! I let pairing get dealt with by the operating system. The code to create a  Car object that is drivable over Bluetooth is very straight forward in pure Python: import socket import time class BluetoothCar : def __init__ ( self , mac_address = "00:12:05:09:98:36" ): self . socket = socket . socket ( socket . AF_BLUETOOTH , socket . SOCK_STREAM , socket .

Matplotlib in Django

The official django tutorial is very good, it stops short of displaying data with matplotlib - which could be very handy for dsp or automated testing. This is an extension to the tutorial. So first you must do the official tutorial! Complete the tutorial (as of writing this up to part 4). Adding an image to a view To start with we will take a static image from the hard drive and display it on the polls index page. Usually if it really is a static image this would be managed by the webserver eg apache. For introduction purposes we will get django to serve the static image. To do this we first need to change the template. Change the template At the moment poll_list.html probably looks something like this: <h1>Django test app - Polls</h1> {% if object_list %} <ul> {% for object in object_list %} <li><a href="/polls/{{object.id}}">{{ object.question }}</a></li> {% endfor %} </ul> {% else %} <p>No polls

Homomorphic encryption using RSA

I recently had cause to briefly look into Homomorphic Encryption , the process of carrying out computations on encrypted data. This technique allows for privacy preserving computation. Fully homomorphic encryption (FHE) allows both addition and multiplication, but is (currently) impractically slow. Partially homomorphic encryption just has to meet one of these criteria and can be much more efficient. An unintended, but well-known, malleability in the common RSA algorithm means that the multiplication of ciphertexts is equal to the multiplication of the original messages. So unpadded RSA is a partially homomorphic encryption system. RSA is beautiful in how simple it is. See wikipedia to see how to generate the public ( e , m ) and private keys ( d , m ). Given a message x it is encrypted with the public keys it to get the ciphertext C ( x ) with: C ( x ) = x e mod m To decrypt a ciphertext C ( x ) one applies the private key: m = C ( x ) d mod m The homomorphic prop