“Tornado is an open source version of the scalable, non-blocking web server and tools that power FriendFeed”

We’re using Mako to handle our templates (vs the template module that comes with Tornado). It’s super fast and feature rich and has good documentation. Bellow is a base class I wrote that illustrates how to render Mako templates from a Tornado RequestHandler class. It takes care of setting your template directory, template cache directory and your output encoding (utf-8).

Note: This example assumes that you have your template settings defined as tornado options but they could be very easily just hard coded in.

from tornado.web import RequestHandler
from mako.template import Template
from mako.lookup import TemplateLookup
from tornado.options import options

class BaseRequest(RequestHandler):
    def __init__(self, application, request, transforms=None):
        RequestHandler.__init__(self, application, request, transforms)
        self.lookup = TemplateLookup(directories=[options.template_dir], module_directory=options.mako_modules_dir, output_encoding='utf-8', encoding_errors='replace')

    def render_template(self,template_name, **kwargs):
        new_template = self.lookup.get_template(template_name)
        self.write(new_template.render(**kwargs))

Basically you would just derive your handlers from BaseRequest vs from RequestHandler and you will then be able to render your Mako templates via the render_template method.

Here is an example:

class ExampleHandler(BaseRequest):
    def get(self):
        self.render_template('example.html')

Shoot me a comment and let me know if you have any questions.

Now not that there aren’t some decent PHP frameworks out there but lets be honest if I had my druthers the clear winner would ALWAYS be Python/Django. Once in awhile I will get someone who is a little bit more open minded and they will suggest Rails. Which again is fine… I would rather write Ruby then PHP any day but it still is a far cry from Django IMHO.

So my question is this… how do you sell a client on the idea of using Django?! I would love to hear your thoughts about it. To preface my client base is normally entertainment industry based (Record labels, TV networks and Movie Studios). They tend to have overly bloated IT departments that take 7 months to handle an app we can crank out in a matter of weeks. The usual roadblocks I hear are “we don’t support python” or “we have no python resources to maintain the app after your done”. Basically I think my clients tend to think that I’m suggesting they build in Django not out of trying to use the best tool for the job but more as a job security language (jsl).

Anyway as you can prob tell this is a constant source of frustration and any advice would be very much appreciated.

1. Eclipse with PyDev (part of Aptana now)
2. TextMate with Django Bundle (technically not an IDE but allot of people love it)
3. Netbeans with Django Plugin
4. Wing
5. Komodo with Django Komodo Kit

So I’m sure some of you people out there will say man up… use VIM or Emacs… be a real programmer! To that I say have at it. If that’s your preference then do what works best for you. By all means, leave me a comment and tell my how wrong I am and/or glow about how good your IDE/editor is. Long story short Django is an awesome framework and whatever you choose to work in I hope you enjoy it as much as I have.

On the most basic level a REST API consists of different urls that you can call to get and post content to a web service. This can be pictures (like Flickr) or micro blog posts (like twitter) or even videos (like youtube). When you make a request to a REST API the API responds with a chunk of XML. This XML usually represents one or more data record (they call them resources). For instance if I want to get a list of my recent twitter updates I can make a call to the following url (http://twitter.com/statuses/user_timeline.xml) and I get back an chunk of XML that represents my last 20 status updates. Taking this a step further I can also post a new status update by making a request to http://twitter.com/statuses/update.xml.

One of the key factors to take into account when working with REST APIs are the request methods used when interacting with the API. If your a little fuzzy on what request method means just think of it in terms of a web form (ie method=’post’). GET requests work off of query strings (like so http://mylink.com?id=1) where as POST requests bundle all of the data into the request itself. There is allot you can talk about as far as different request types. You can read more about it here if your still unclear on it.

Most REST APIs are setup so that when you want to get back records from the system you use a GET request. If you want to post records to the system or update an existing record you use a POST request. If your noticing a trend good for you. The convention is to work off of the verb in the sentence… so to get something you use GET and to post something you use POST. Pretty simple right.

Some APIs are set up so that when you want to delete a record you have to send a request as a DELETE method. And some APIs also use the PUT method for doing things like updates or posting files. Allot of services don’t take it to this level as it tends to just confuse people. For now just worry about GET and POST until you get everything straight in your head.

Another point to notice is that most REST APIs not only return a chunk of XML representing the data record but they also return a response status code (200 ok, 404 not found, 500 server error etc). Response status codes are a pretty hefty topic but really simple one you get it. Basically they are a numeric code that represents the status of the response (did it work or not and why). You can read more about them here.

So hopefully that wasn’t too painful. If anything that should  give you at least an introductory understanding of what to expect when you start to play with a REST API. Stay tuned for the next installment of this series when I show language specific (ruby, python) examples of using REST. Feel free to post some questions and I’ll do my best to answer them.

Basically it takes your url & params and dynamically builds the DOM for the form and then submits it.

Requires that you include prototype.js.

Here is an example link. You just pass the url you wish to submit to and an associative array of the params.

post the request

Here is the js function. Include this in the head of your page.

/*
* Dynamically creates a form based on args and submits it to the given url
* @param {Object} url
* @param {Object} params
*/
function post_from_link(url,params){
   var form = new Element('form', { action: url, method: 'POST' });
   for(param in params){
       var hidden = new Element('input', {type:'hidden', name:param, value:params[param]});
       form.insert(hidden);
   }
   document.body.appendChild(form);
   form.submit();
}