Now that the mypy bugs have been resolved, we are able to define more precisely
and cleanly the types of Actions and Filters.
Moreover, can now strongly type named actions and hooks (in consts.py). With
such a strong typing, we get early alerts of hooks called with incorrect
arguments, which is nothing short of awesome :)
This change breaks the hooks API by removing the `context=...` argument. The
reason for that is that we cannot insert arbitrary arguments between `P.args,
P.kwargs`: https://peps.python.org/pep-0612/#the-components-of-a-paramspec
> A function declared as def inner(a: A, b: B, *args: P.args, **kwargs:
> P.kwargs) -> R has type Callable[Concatenate[A, B, P], R]. Placing
> keyword-only parameters between the *args and **kwargs is forbidden.
Getting the documentation to build in nitpicky mode is quite difficult... We
need to add `nitpick_ignore` to the docs conf.py, otherwise sphinx complains
about many missing class references. This, despite upgrading almost all doc
requirements (except docutils).
This is a very large refactoring which aims at making Tutor both more
extendable and more generic. Historically, the Tutor plugin system was
designed as an ad-hoc solution to allow developers to modify their own
Open edX platforms without having to fork Tutor. The plugin API was
simple, but limited, because of its ad-hoc nature. As a consequence,
there were many things that plugin developers could not do, such as
extending different parts of the CLI or adding custom template filters.
Here, we refactor the whole codebase to make use of a generic plugin
system. This system was inspired by the Wordpress plugin API and the
Open edX "hooks and filters" API. The various components are added to a
small core thanks to a set of actions and filters. Actions are callback
functions that can be triggered at different points of the application
lifecycle. Filters are functions that modify some data. Both actions and
filters are collectively named as "hooks". Hooks can optionally be
created within a certain context, which makes it easier to keep track of
which application created which callback.
This new hooks system allows us to provide a Python API that developers
can use to extend their applications. The API reference is added to the
documentation, along with a new plugin development tutorial.
The plugin v0 API remains supported for backward compatibility of
existing plugins.
Done:
- Do not load commands from plugins which are not enabled.
- Load enabled plugins once on start.
- Implement contexts for actions and filters, which allow us to keep track of
the source of every hook.
- Migrate patches
- Migrate commands
- Migrate plugin detection
- Migrate templates_root
- Migrate config
- Migrate template environment globals and filters
- Migrate hooks to tasks
- Generate hook documentation
- Generate patch reference documentation
- Add the concept of action priority
Close #499.
The "latest" tag is a pain to maintain: it's a tag that we delete and
re-create at every release. Whenever we delete it, the binaries become
unavailable on Github until they are re-generated. Thus, from now on, we
conform to good practices (as examplified by the
github.com/docker/compose) project and distribute only pinned release.
The "nightly" tag remains, for now, as it allows us to distribute beta
features. It may disappear in the future.
