Dagny

Dagny is a Django adaptation of Ruby on Rails’s Resource-Oriented Architecture (a.k.a. ‘RESTful Rails’).
Dagny makes it really easy to build resourceful web applications.

You can read the full documentation here.

At present, this project is in an experimental phase, so APIs are very liable to change. You have been warned.

P.S.: the name is a reference.

Motivation

Rails makes building RESTful web applications incredibly easy, because resource-orientation is baked into the framework—it’s actually harder to make your app unRESTful.

I wanted to build a similar system for Django; one that made it incredibly simple to model my resources and serve them up with the minimum possible code.

One of the most important requirements was powerful yet simple content negotiation: separating application logic from the rendering of responses makes writing an API an effortless task.

Finally, as strong as Rails’s inspiration was, it still needed to be consistent with the practices and idioms of the Django and Python ecosystems. Dagny doesn’t use any metaclasses (yet), and the code is well-documented and readable by most Pythonista’s standards.

Appetizer

Define a resource:

from dagny import Resource, action
from django.shortcuts import get_object_or_404, redirect
from polls import forms, models

class Poll(Resource):

    @action
    def index(self):
        self.polls = models.Poll.objects.all()

    @action
    def new(self):
        self.form = forms.PollForm()

    @action
    def create(self):
        self.form = forms.PollForm(self.request.POST)
        if self.form.is_valid():
            self.poll = self.form.save()
            return redirect("Poll#show", self.poll.id)

        return self.new.render()

    @action
    def edit(self, poll_id):
        self.poll = get_object_or_404(models.Poll, id=int(poll_id))
        self.form = forms.PollForm(instance=self.poll)

    @action
    def update(self, poll_id):
        self.poll = get_object_or_404(models.Poll, id=int(poll_id))
        self.form = forms.PollForm(self.request.POST, instance=self.poll)
        if self.form.is_valid():
            self.form.save()
            return redirect("Poll#show", self.poll.id)

        return self.edit.render()

    @action
    def destroy(self, poll_id):
        self.poll = get_object_or_404(models.Poll, id=int(poll_id))
        self.poll.delete()
        return redirect("Poll#index")

Create the templates:

<!-- polls/index.html -->
<ol>
  {% for poll in self.polls %}
    <li><a href="{% url Poll#show poll.id %}">{{ poll.name }}</a></li>
  {% endfor %}
</ol>
<p><a href="{% url Poll#new %}">Create a poll</a></p>

<!-- polls/new.html -->
<form method="post" action="{% url Poll#create %}">
  {% csrf_token %}
  {{ self.form.as_p }}
  <input type="submit" value="Create Poll" />
</form>

<!-- polls/show.html -->
<p>Name: {{ self.poll.name }}</p>
<p><a href="{% url Poll#edit self.poll.id %}">Edit this poll</a></p>

<!-- polls/edit.html -->
<form method="post" action="{% url Poll#update self.poll.id %}">
  {% csrf_token %}
  {{ self.form.as_p }}
  <input type="submit" value="Update poll" />
</form>

Set up the URLs:

from django.conf.urls.defaults import *
from dagny.urls import resources

urlpatterns = patterns('',
    (r'^polls/', resources('polls.resources.Poll', name='Poll')),
)

Done.

Example Project

There’s a more comprehensive example project which showcases a user management app, built in very few lines of code on top of the standard django.contrib.auth app.

To get it running:

git clone 'git://github.com/zacharyvoase/dagny.git'
cd dagny/
pip install -r REQUIREMENTS  # Installs runtime requirements
pip install -r REQUIREMENTS.test  # Installs testing requirements
cd example/
./manage.py syncdb  # Creates db/development.sqlite3
./manage.py test users  # Runs all the tests
./manage.py runserver

Then just visit http://localhost:8000/users/ to see it in action!

License

This is free and unencumbered software released into the public domain.

Anyone is free to copy, modify, publish, use, compile, sell, or distribute this software, either in source code form or as a compiled binary, for any purpose, commercial or non-commercial, and by any means.

In jurisdictions that recognize copyright laws, the author or authors of this software dedicate any and all copyright interest in the software to the public domain. We make this dedication for the benefit of the public at large and to the detriment of our heirs and successors. We intend this dedication to be an overt act of relinquishment in perpetuity of all present and future rights to this software under copyright law.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

For more information, please refer to http://unlicense.org/