Django App Plugins#
Overview#
Provides functionality to enable improved plugin support of Django apps.
This can be used to extend any service with code that is not core to the service, but will become discoverable by that service for an individual deployment.
Once a Django project is enhanced with this functionality, any participating Django app (a.k.a. Plugin App) that is PIP-installed on the system is automatically included in the Django project’s INSTALLED_APPS list. In addition, the participating Django app’s URLs and Settings are automatically recognized by the Django project. Furthermore, the Plugin Signals feature allows Plugin Apps to shift their dependencies on Django Signal Senders from code-time to runtime.
While Django+Python already support dynamic installation of components/apps, they do not have out-of-the-box support for plugin apps that auto-install into a containing Django project.
Enable Plugins in an IDA#
Creating a Plugin App#
See how to create a plugin app.
Note
Do not use this plugin framework for required apps. Instead, explicitly add your required app to the INSTALLED_APPS of the IDA.
Design Principles#
This Django App Plugin functionality allows for Django-framework code to be encapsulated within each Django app, rather than having a monolith Project that is aware of the details of its Django apps. It is motivated by the following design principles:
Single Responsibility Principle, which says “a class or module should have one, and only one, reason to change.” When code related to a single Django app changes, there’s no reason for its containing project to also change. The encapsulation and modularity resulting from code being co-located with its owning Django app helps prevent “God objects” that have too much responsibility and knowledge of the details.
Open Closed Principle, which says “software entities should be open for extension, but closed for modification.” IDAs are extensible via installation of Django apps. Having automatic Django App Plugin support allows for this extensibility without modification to an IDA. Currently, this is only set up in edx platform. Going forward, we expect this capability to be widely used by other IDAs to enable enhancement without need to modify core IDA code.
Dependency Inversion Principle, which says “high level modules should not depend upon low level modules.” The high-level module here is the Django project, while the participating Django app is the low-level module. For long-term maintenance of a system, dependencies should go from low-level modules/details to higher level ones.