django: modifying/extending 3rd party apps

Question

a newbie django question

I want to use 3rd party app, but I need to make some mods to it (in this case, the app is django-registration, and I need to change things such as allowing registration without confirmation email)

Initially, I simply installed the app in the general site-packages folder, and changed the code there. Now that I put my code on bitbucket I need a way to be able to keep my mods in the repository in a usable way, and uploading the full python code doesn't sound like a good idea.

I guess the best way would be to keep the 3rd party app in site-packages, and create an app in my project to keep my changes. In my case, I'd create my-django-registration in my project, and then import this when I need it in my code, rather than django-registration.

I also read about virtualenv, but I think that's mostly used for being able to use multiple environments in the same machine (in fact, somewhere it advises against changing the modules installed in the virtualenv), and doesn't help me with keeping my changes in a repository.

Any comments welcome! Thanks

Answer 1

In general, you should reuse and override the behavior in 3rd party apps and not modify their sources.

What you'll most often encounter is that apps ship models that may not necessarily cover your needs, but do most of the work; you'll have forms that are almost perfect, but need that little something; you'll have views that would be perfect if you can just change one thing; you'll have URLs that are sane, but you need something more from them.

In most cases, that would just require that you create a custom app and rewire everything. Ship your own URLs that map to views that you've extended and overrode methods for custom behavior; supply it with a model form who's Meta is using the new model that you've extended from the original; so forth...

That's just the tip of the iceberg of what you can do, there's more ways when your creative. I can give you an example of how I've used the RegistrationProfile model, but shipped my own URL patterns and a custom class-based view that handled the registration process.

Now, where virtualenv comes into play is that you'll most likely be using pip to specify and supply your required dependencies in the requirements file format. That's when you want to say: "I've extended the django-registration app, but it won't work cleanly with just any version. It has to be of release X", or , "a checkout from the repository of commit Y".