This commit completes the program_enrollments LMS app
Python API for the time being. It does the following:
* Add bulk-lookup of users by external key in api/reading.py
* Add bulk-writing of program enrollments in api/writing.py
* Move grade-reading to api/grades.py
* Refactor api/linking.py to use api/writing.py
* Refactor signals.py to use api/linking.py
* Update rest_api/v1/views.py to utilize all these changes
* Update linking management command and support tool to use API
* Remove outdated tests from test_models.py
* Misc. cleanup
EDUCATOR-4321
This is the third in a series of commits to create
a Python API for the LMS program_enrollments app.
It does the following:
* Creates api/ folder.
* Moves link_program_enrollments.py to api/linking.py
* Creates api/reading.py for enrollment-fetching
functions.
* Updates rest of app to use api/reading.py when
it was going directly through the models before.
* Other misc. cleanup (isorting, unicode_literals,
line breaks, etc).
Still to do:
* Create api/writing.py and update app to use it instead
of going directly through models.
* Create api/reset.py and api/expire.py, which the management
commands call out to.
EDUCATOR-4321
This is the first in a series of commits to create
a Python API for the LMS program_enrollments app.
We do some general refactoring, renaming, and clean-up
in order to move toward the creation of that API.
EDUCATOR-4321
