Deviding Django application (social network) to Django Frontend and RESTfull API - django

I'm writing Django application (social network) and thinking about dividing monolithic project to two projects: UI and API. For example, Django will be used only to render pages, interacting with and taking data from API, written on web.py.
Pros are following:
I can develop and test API independently.
In the future, other UI can appears (mobile, for example), it will require service.
I plan to outsource web UI developing, so, if my application will have two modules, I can provide outside only UI one, not sharing logic of application.
Cons are following:
I'm working alone, and developing two projects are harder, then one.
I will not be able to use cool Django admin panel. I will need to write my own.
web.py is more low-level comparing with Django.
It's like a brain dump, but I will be really appreciated if you share your experience in creating web application with UI module and independent API module.
Update (more specific question, as Mike asked)
What Python framework will you use for creating REST API of social network, which can be used by different client applications? Is using web.py that returns JSON only and rendering it by Django for web is good idea?
Thanks,
Boris.

I've been in a situation similar to yours. I ended up writing both, the UI and the API part in Django. Currently, I am serving them both out of the same process/project. You mentioned you wanted to be able to outsource the UI development, but do hear me out.
In the meantime, I have used django-piston to implement the RESTful front end, but a bit of preparation went into it:
Encapsulate all DB and ORM accesses into a library. You can do that either for your entire project, or on an app by app basis. The library is not just a low-level wrapper around your DB accesses, but also can be for higher-level 'questions', such as "all_comments_posted_by_friends()" or something. This accomplishes two things:
You can call your pre-canned queries from UI views as well as API views without having to re-implement them in multiple places.
You will later be able to replace some - if not all - of the underlying DB logic if you ever feel like going to a NoSQL database, for example, to some other distributed storage model. You can setup your entire app of this ahead of time, without actually having to worry about the complicated details of this right at the start.
The authentication layer for the API was able to accept an HMAC/token based header for programmatic access and normal Django auth. I setup the views in such a way that they would render plain JSON for the programmatic clients (based on content-type), and would render the data structure in HTML (with clickable links and clickable docstrings) if browsed by a human from a browser. This makes it possible that the API is fully explorable and clickable by a human without having to read any docs, while at the same time it can be easily processed by a client just via JSON.
On effect, the database layer I build serves as the internal API. This same database layer can be used from multiple applications, multiple processes, if you wish to do so. The UI views and the REST views were both implemented in Django. They can either be in the same process or in separate processes (as long as they have access to the same database right now).

Related

Django&REST-framework architecture

Hello I am tasked with translating a current Excel tool to a web application. I decided to use Python and Django. Lately I studied the Django REST framework. I have the following related questions.
Is it for such an application a good idea to first write a web REST API so that I
firstly only need to focus on the backbone of the web application. I.e. implement the PUT, POST, GET and DELETE methods and the Django models.
The second step would be to implement the user interface... But if this is a valid method how can I reuse the REST views??? I followed the REST tutorials, but they don't show how to build a nice slick user-interface on top of the REST API.
Since REST views inherit from Django, I think it's maybe not such a good idea to write a Django view which inherits from a REST Apiview? Or can I directly use an API endpoint in a template. If so where can I get some nice examples?
Writing the back-end separately using Django REST Framework is a great idea.
There is a strong architecture based on the idea of decoupling the back-end from the front-end. After you finish the project's backbone, as you are calling it, you can start creating you front-end but your don't have to use Django template rendering in that case.
You can take the pros of using REST APIs and you can use one of the good front-end frameworks or libraries as Angular and React.js.
Another advantage of this that the same API can work with mobile development and so on.
So you develop one back-end and multiple front-ends depends on your need.
Also you can read a discussion about your question on Quora: https://www.quora.com/Why-does-it-make-sense-to-separate-front-end-from-back-end

Running a meteor app as part of a wider django project

I'm currently working on a project which would require some realtime functionalities such as Multi-user chatrooms etc.
Ideally, I’m looking to have meteor run the chat application(on a different port) and mongodb act as message broker to the django back-end which would take care of user registration , management and everything 'non-realtime' related.
This would involve setting up a reverse-proxy which would redirect to a different port based on the url (please let me know if i'm wrong in this)
Would this be possible(or even advisable)? Another option would be to implement the same with tornado. but I have no experience with building tornado-based apps and rather do this with a framework I’m comfortable with.
Thanks,
You can have Django serve the Meteor front-end while providing access to its data using django-ddp, giving you some distinct advantages:
Continue to serve your existing Django project/apps.
No extra services or ports to manage.
Scale out by simply adding more front-end Python/Django servers (server to server IPC is done via the existing database connection).
Use django.contrib.auth user accounts in your Meteor app.
Familiar Python/Django code (no "callback" style such as with Tornado).
Use time-tested, trusted relational databases.
Use Django migrations to effectively manage schema changes.
There's a Gitter chat room where I can give you assistance if you need it.
DISCLAIMER: I'm the author of django-ddp.
A meteor application is more than capable of handling the user registration flow and many other things. Why not just build the application entirely in meteor? Your application sounds like a perfect candidate for meteor, with realtime interaction with your database at the core.
The other option would be to use swampdragon which adds realtime data binding within django. It allows for simple bi directional communication between the server and the client. Again, essential for a chat application. It nice and easy to get setup and running as well.
Are there any specific reasons to not implementing your application in one framework alone?

Symfony2 website and RESTful API

I'm currently developing a web application, that relies heavily on mobile and desktop clients consulting the web server for information. This can be accomplished nicely making a RESTful API available to handle this. So my idea is to have an application acting as the "platform" which handles all the real business logic and database information behind the curtains.
My plan is to make the platform using symfony2 and OAuth 2.0 authentication mechanisms, combined with RESTful web services.
Now my real dilema comes on the website component. Ideally I would like to think of the website as yet another client that asks this REST platform for information, and completely separate it from the platform itself.
To make it a little bit more clear, let's say we are making a blog with this architecture, so one would have a "platform/backend" that provides a rest service to list articles, for example: /articles/5. This on the backend, and with symfony2/doctrine means that the app has an Article model class, and these can be requested from the DB. A simple controller queries for the Article number 5 and returns all the information in JSON format.
Now the website on this example, could just do the easy thing and also have an Article entity and just query the database directly, but I think it would be cleaner if it could just talk to the platform through it's REST api and use that information as a "backend" for the entities.
So the real question would be, is there anyway to support this kind of design using symfony2? Have entities rely on a REST api for CRUD operations? Or I'm just better off making the platform/website a single thing and share a "CoreBundle" with all the generic entities?
There is nothing in Symfony that prevents you from doing you want.
On the client side you could use Backbone.js or Spine.js.
Have a look at FosRestBundle, it makes your life much easier to create api:
https://github.com/FriendsOfSymfony/FOSRestBundle/blob/master/Resources/doc/index.md

If I am using Django as my front end application, does using Cherrypy to manage equipment abstraction make sense?

I am building a application that services users via a web front end, which I have chosen to use Django for. I also have to choose a framework/libraries to provide management of and abstracted access to a bunch of embedded systems that provide information the web user gets to see in one form or another.
I like the idea of sticking with a restful approach to access the backend application which provides the hardware generated resources. Does it make sense to use Django for the front end and CherryPy for the backend? Or should I just use Django for both and ignore the stuff I don't need in django for the backend.
I guess another way to ask, is what do I gain by using CherryPy as the backend that out ways having to know two sets of libraries/frameworks.
I don't see any real benefit, only added complexity in the long run. If you are using Django's ORM, you'll want to build the REST interface around that anyways. For building REST interfaces with Django I like using django-tastypie which makes it easy to build RESTful APIs supporting authentication/authorization, validation, various types of serialization, throttling, caching, etc. I also rather like django-piston, which is also quite popular.

Should my web based app be a consumer of my api?

I will be developing a mobile app (iPhone) and a web based app (Django) soon. For the mobile app I will be creating a REST api (most likely using Django) to send data back and forth from phone to server.
When I comes time to create the web based version does it make sense to just create it as any other client of the api. In other words both the mobile app and the web app will get there data from an external API over HTTP. Or should the web based app have direct access to the database that the api is using and just get its data that way?
Break it into three "sections". The first uses a Python API to manipulate the database. The second interfaces your REST API with your Python API. The third talks web and uses the Python API.
I would create the web application to serve the API to the mobile client. That is, give the web based application direct access to the database. This will simplify your XML / JSON RESTful resource access.
I would say no, don't use the API for the HTML version. If you design your Django well, you can end up with less code than using the API for the HTML version. You also get to retain the ability to have a web designer work with the Django templates whenever the boss wants the spelling changed on something.
I'd suggest trying to define a base app for your iPhone app to interface with, and then extend that within a second app for the HTML version. App1 would have all of your models (including business logic), and a views.py for processing the data to/from the iPhone. Then create App2 which uses App1.models, but creates its own views.py. With any luck, you'll find yourself with the ability to change nothing but the template used to render the output, so you can reuse your views by passing the template as an argument.
For example:
App1.views:
def list(request, template="list.json"):
list = Model.objects.filter(deleted=False).filter(user=request.user)
list.reverse()
## Lots of other logic to work on the list.
return render_to_response(template, {list: list,})
App2.views:
def list(request, template="list.html"):
return App1.views.list(request, template=template)
I think the answer to this question has changed over time. A year ago when asked it was probably still too much hassle to do this, but now I'd definitely say yes - using your API as the basis is the smart thing to do. As Web sites use more HTML5 and Mobile apps get smarter it really makes sense to have all your "UIs" read/writing from the same API layer. This will give you much more flexibility in the future.