[#1760] Implemented user feed

[Bartvaderkin]

Review notes:

It's a lot of files, but to get an idea of how it works first look at:

• open_inwoner/userfeed/feed.py for the get_feed(user) that is the main entry for retrieval and display (in the plugin etc)
• open_inwoner/userfeed/hooks/*.py for the 'hook' functions that create items of a specific type, the function to mark some as completed, and their optional 'adapter' class that generalizes the type for display by get_feed() (and the template etc)

Everything else is just glue to make it work or to tie it into the rest of the application. Note the liberal use of patch/mock in the tests to keep the user feed specific tests out of the other parts of the code.

In the future we'll add more item types to the choices/hooks/adapters.

---

To test the plugin put it on the homepage, and then run this command to add a test message:

python src/manage.py add_feed_message --user 1 --title "Helo World" --message "Waddup?" --url "http://www.maykinmedia.nl"

These never expire, so delete from /admin/userfeed/feeditemdata/. To find valid --user User id's use the command without arguments and it prints staff users:

python src/manage.py add_feed_message

[codecov-commenter]

Codecov Report

Attention: 17 lines in your changes are missing coverage. Please review.

Comparison is base (b3f5504) 93.11% compared to head (a2c9d69) 94.80%.
Report is 44 commits behind head on develop.

Files	Patch %	Lines
...r/userfeed/management/commands/add_feed_message.py	69.56%	7 Missing ⚠️
src/open_inwoner/userfeed/models.py	93.65%	4 Missing ⚠️
src/open_inwoner/userfeed/adapters.py	86.36%	3 Missing ⚠️
src/open_inwoner/openzaak/utils.py	87.50%	1 Missing ⚠️
src/open_inwoner/userfeed/adapter.py	97.05%	1 Missing ⚠️
src/open_inwoner/userfeed/feed.py	98.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #933      +/-   ##
===========================================
+ Coverage    93.11%   94.80%   +1.69%     
===========================================
  Files          829      857      +28     
  Lines        29142    30046     +904     
===========================================
+ Hits         27135    28485    +1350     
+ Misses        2007     1561     -446     

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[stevenbal]

Looks good overall 👍, just a few minor remarks/questions

[pi-sigma]

I've noticed a pattern with the userfeed hooks: the function names are not very descriptive, which is why every time you're hooking into the userfeed you need to add comments to indicate what you're doing.

Alternatively, you could try the following pattern:

• import the hook functions (e.g. plan_expiring) in userfeed.hooks.__init__
• in management.commands.plans_expire:
  • from open_inwoner.userfeed import hooks as userfeed_hooks
  • for p in plans: userfeed_hooks.plan_expiring(receiver,p)
• modify the relevant patch in test_plans_expire: @patch("open_inwoner.plans.management.commands.plans_expire.userfeed_hooks.plan_expiring")

The code would be self-explanatory, and comments would be unnecessary. The same pattern would work for the other cases (I think).

[Bartvaderkin]

OK this is also how some of the timelinelogs works so let's do that.

[Bartvaderkin]

@stevenbal @pi-sigma I applied the PR fixes.

Also: there was a mistake in the logic where the incoming-notification handler would check and bail early for emailable Users and would never reach the userfeed hook if the users had a bad email or email-notifications disabled. I fixed it in the last commit.