Comments on: what can you do with django?

By: Simon Willison

Simon Willison — Mon, 03 Dec 2007 00:04:41 +0000

There’s a Django middleware component that can validate your HTML and tell you if you have any errors: http://lukeplant.me.uk/resources/djangovalidator/

Both CSS and JavaScript are deliberately not covered by Django; it’s a server-side framework and those are client-side technologies, so Django expects that you are smart enough to be able to pick your own JavaScript library and CSS tools. You might want to take a look at Blueprint ( http://code.google.com/p/blueprintcss/ ) which actually has its roots in the same team as Django (the team at the Lawrence Journal-World newspaper).

Keeping models in sync with database changes is a really hard problem. The best solution at the moment is probably Django Evolution: http://code.google.com/p/django-evolution/

Django does extremely well in performance comparisons with Rails, for a couple of reasons: firstly, Python is a great deal faster than Ruby due to a better (in terms of speed) implementation of the language interpreter. Secondly, many of the design decisions in Django were strongly influenced by performance considerations – things like the way the template engine works and many aspects of the ORM.

By: numerodix

numerodix — Sun, 02 Dec 2007 23:14:25 +0000

Good points. What I meant about css is that html/css is basically a minefield of bugs, it’s hard to do the simplest thing right and get the same result in all browsers. And since django is about empowering web developers, and it’s generally so nice… well it would be cool if they had some answer to that as well

By: tante

tante — Sun, 02 Dec 2007 22:50:48 +0000

@1: Templates are “rendered” with a given “context” (the stuff you want to insert into them). If you wanted to make sure that the rendered code it valid, you can just pipe the rendered data through something like “tidy”. There are shortcuts in django like “render_to_response(”template”,context)” but those just simplify default tasks. No problem at all to write something similar that does use tidy to create valid code (or does at least check and sends te administrator an email of some function returns invalid code)

@2: CSS is a designer’s job, what does it have to do with the application writer? The guys writing the model and the view shouldn’t need to know about CSS, just the guy writing the actual template. And I don’t see where django could automate things there. You can of course use any CSS/JS framework you want with django without any problem, but the MVC thingy is exactly what decouples the templates (where the CSS matters) from the rest.

@3: There’s some work done on a few apps that offer “migrations” between changed django models so that will end up in mainline django at some point. Right now it’s a design decision because automatic migrations are a pain in the ass and might either destroy data or create crappy SQL structures. Since they couldn’t do it right (lack of time) they left it out. That is actually what I love about django: What’s in there feels like it has been done right, not just hacked together into some weird “plugin”.

From my experience django with memcache and postgresql scales really good. I think it might scale somewhat worse than PHP but that is a price I’m willing to pay for the structure that django enforces and the great workflow.