I understand that full django can be used out of the box with CloudSQL. But I'm interested in using HRD. I'd like to learn more about what percentage of django can be used with nonrel. Does middleware work? How about other features of the framework like i18n, forms, etc. Also does nonrel work with NDB?
The background here is that I've even using webapp2 and before that webapp and find them great until your project gets bigger. So for this project I'm interested to reevaluate other options.
The big limitation is that the datastore doesn't do JOINs, so anything that uses JOINS, like many-to-many relations won't work.
Any packages/middleware that uses many-to-many won't work, but others will.
For example, the sessions/auth middleware will work. But if you use permissions with auth, it won't. If you use the admin pages for auth, they use permissions, so you'll have some trouble with those too.
i8n works.
forms work.
nonrel does not work with ndb.
I don't know what you mean by "until your project gets bigger". django-nonrel won't help with the size of your app.
In my opinion there's two big reasons to use nonrel:
You're non-committal about App Engine. Nonrel potentially allows you to move to MongoDB as a backend.
You want to use django packages for "free". For example, I used tastypie for a REST API, and django-social-auth to get OAuth for FB/Twitter logins with very little effort. (On the flip side, with 1.7.0, they've addressed the REST API with endpoints)
Related
I have read a couple of articles about using new JS frameworks like Backbone.js or Ember.js
I have come up to this statement:
If I use a JS framework like Backbone.js/Ember.js, I then move the logic from the back-end (Django) to the front-end.
Therefore, will Django actually be used only for its Models?
Does that mean that Django Views and Django Template are not needed anymore and the Django back-end is kinda turn into a "basic" REST API that will be consumed by the front end.
Do you agree? Is it then the purpose of Django in this case?
Is turning the django backend into a REST API one of the most suitable use case when using a framework like Backbone.js/Ember.js for the front-end?
Thanks.
Django is perfectly fine to be used this way, you still get the admin, the models, the orm and all the third-party plugins. However, it isn't blazingly fast, so if you're doing simple document level, non-relational REST mapping, you might wan't to look into node.js and mongoDB for instance.
If you're sticking with django (like we are, we like the structure it gives us), you can use one of the REST plugins:
Django Rest Framework A perfect match since DRF 2.0, under very active development!
Django Tastypie (checkout backbone-tastypie.js for integration)
Django Piston (might be a bit stale or has development picked up lately?)
If you only want to work with frontend development, checkout the Backend-as-a-Service places like cloudmine.me or firebase.com that handle all backend stuff for you, for a price of course.
Django may seem unnecessary once you start thinking about single page solutions and Javascript applications, but if you want your site to be 'fail proof' it wouldn't be impossible to develop both a client side Javascript version of the site as well as a backend django side incase the user, or your site's javascript, fails at some level. Of course this requires creating your site twice, and probably isn't needed in the age of modern browsers, but such would be one of the few instances where you would mix the two for a complete solution.
Yes, that's about it. You can use it to manage authentication to resources and such and maybe use a main view for your application but you won't need to use the server side templating since these frameworks are made to work with json/xml response.
That's why a lot of people are moving to lighter backend/backbone or ember combo instead of a complete solution like django. You can also use your django for caching json response which makes your application appears faster.
We are doing that and use django-piston to make it easier on you.
Normally you make your entire website under Django and only one page will be a "single app page" using backbone.js, usually that page is a very interactive page, with lots of small updates that occur frequently and need to be shown very fast to the user. This page, because of the large number of changes and user interactions is constructed on the client-side so that you are using his PC resources and not the server's, the rest of the pages can use django because it offers you a very stable and secure framework for the server-side
According to the documentation, an app is a module which deals a well defined operation.
Is it correct to think about an app as a REST-based service? or is it mandatory to use some framework like piston or tastypie to create a RESTful web service around an app?
Generally, no. Django app is really just a python module, with some interfaces to django internals like models, urls, admin discovery etc.
To implement REST, you still have to manage network communications via views, and this is where you either write your own code or use the help of tastypie/piston/etc.
Please do have a look at django-rest-framework, I just stepped over from tastypie to this new framework, works great!
http://django-rest-framework.org/
Especially the class based views and the browsable api! and may other advantages (e..g. to upload images)
And to answer your question:
The rest-base service is an extra entry to your webapp.
I made some api's for some projects using the django-rest-framework, most project members were surprised they got a webapp as an extra, while it was actually the other way around. You make a django app (with views models and urls) and on top off that you make the api.
I am looking for a guide to migrate Django project to Google App Engine and use Google's datastore. The most of the guides I found were linked to Django-Appengine using Django-nonrel (but I want to use GAE's native support).
Going through GAE getting started guide, it says:
Google App Engine supports any framework written in pure Python that speaks CGI (and any WSGI-compliant framework using a CGI adaptor), including Django, CherryPy, Pylons, web.py, and web2py. You can bundle a framework of your choosing with your application code by copying its code into your application directory.
I understand that I won't be able to use some features of Django in that case (majorly the admin feature) and would also need to restructure the models.
From other reading, I also found that latest SDK of GAE now includes Django 1.3 on Python 2.5.
I tried to put all files from my Django application to a GAE project, but couldn't get it all to work together.
Please provide some basic guide using which I may migrate my Django project to Google App Engine's code.
Thanks.
For an existing Django app, using django-nonrel is the simplest approach; it is very popular so you should be able to find help with specific errors you get quickly.
Another approach is written up in this article: http://code.google.com/appengine/articles/pure_django.html -- it goes the other way, taking an App Engine app that uses Django for dispatch, templates, and forms, but not for models, and describes how to make it run in a native Django environment. Maybe you can glean some useful hints for your situation from it.
I've used django-nonrel, which behaves pretty much like django, except that operations with JOINs will return errors. I've basically worked around this by avoiding ManyToMany fields, and essentially building that functionality manually with an intermediate table.
So far I've ran into two problems with Django-nonrel:
1. No access to ancestor queries, which can be run in a transaction. There's a pending pull request for this feature though.
2. You can't specify fields that are not indexed. This could significantly increase your write costs. I have an idea to fix this, but I haven't done so yet.
(Edit: You CAN specify fields that are not indexed, and I've verified this works well).
2 (new). Google is pushing a new database backend called ndb that does automatic caching and batching, which will not be available with django-nonrel.
If you decide not to use django-nonrel, the main differences are that Django models do not run under App Engine. You'll have to rewrite your models to inherit from App Engine's db.Model. Your forms that use Django's ModelForm will need to inherit from google.appengine.ext.db.djangoforms instead. Once you're on App Engine, you'd have to port back Django if you ever take your app somewher else.
If you already have a Django application you might want to check this out. You won't work with App Engine's datastore but Google Cloud SQL might fit your needs.
According to this question:
Django on Google App Engine
The easiest way to get started with GAE/Django is with the Django non-rel bundle. However now that the latest Python/GAE SDK includes a build of Django, do we still need this?
What's the best-practice for getting started wth Django on GAE right now?
Thanks
Update: It seems that Web app2 is the easiest choice for new projects.
This guest article suggests that
"App Engine does come with some Django support, but this is mainly
only the templating and views."
non-rel is still seemingly your best bet. Although I'd caution you that further development and/or maintenance may not happen according to their blog.
Normal Django's models doesn't have a backend supporting GAE's datastore. Hence you can't use Django models, and hence, Django's model forms. What you'd have to do use use models derived from GAE's python db.Model(). Instead of using Django's ModelForm class for forms, you would use google.appengine.ext.db.djangoforms. Note, that's specifically for ModelForms, other forms work fine since they're not tied to the database.
I can think of two good reasons to use Django-nonrel:
1a) you have a existing project on Django. Using Django-nonrel would be the laziest way to go. Rewriting models to GAE's models isn't too hard, but it could be a small pain, especially if
1b) you use a lot of existing Django components, and you'd have to go through all of them to update the models and forms.
2) You want to hedge your bets against GAE. Using Django-nonrel will allow you to switch over to MongoDB with very little effort, since Django-nonrel has a functioning MongoDB backend. The current Django-nonrel maintainers seem to be more interested in MongoDB.
Having worked with Django-nonrel, I've so far run into some reasons why it may be a bad choice:
1) No support for ancestor queries. There's an outstanding pull request for this though. It won't be compatible with any other DB backend though.
2) ndb is coming out, and seems like it'll have a few more benefits, that likely won't see support on Django-nonrel.
If you do use GAE's native db API, the main benefit from Django would be the form validation. Otherwise, webapp2+jinja2+gae db.Models() would provide similar functionality to Django.
i'm developing a web site hosted on AppEngine and wanted to use Django for some tasks. I've read these two answers:
Django on Google App Engine
Django and App Engine
But those are pretty old, and my question is a little more specific. I've taken a look at django-nonrel and seems good, but i've not used it and cant affirm anything.
So, the question is. Can I use the Admin site and the forms from Django with this package? If not, do you know any other patch that allow me to use them?
Thank you very much!
If you use django-nonrel, then you can use the Django admin site but it will be limited to the types of queries you can do on app engine. I personally found it easier to code my own simple admin interfaces that to type to make things work in Django Admin.
Regarding forms, regular Django Forms and ModelForms work quite well.
Yes, you can (both Admin and forms).
(definitely) :)
I installed djangoappengine 3 months ago and work on it daily under Eclipse (Windows).
If you have some expericence with Django it should be easy, I faced much more problems with Eclipse integration, but nothing unfeseable (even for a newbie - as I'm still).
You just have to start from here:
http://www.allbuttonspressed.com/projects/djangoappengine#installation
Be careful anyway: there are some limitations due to the Datastore capabilities.
A lot of work has been done to circumvent them (dbindexer, specifics decorators...) and if you're planning to develop an app from scratch you will find your way (keeping " noSQL " in mind) but if you plan to migrate a plain vanilla SQL app, it may cause you some pain...
Last point: instances handling Django and all its libraries may be long to start with App Engine ; an issue to consider:
http://code.google.com/p/googleappengine/issues/detail?id=1695
Hope it helps.
Florent