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An Exercise for the Reader
Here’s an outline of the steps to take to get this new feature implemented:
1. We’ll need a new section in
list.html
, with, at first, a form with an input box for an
email address. That should get the FT one step further.
2. Next, we’ll need a view for the form to submit to. Start by defining the URL in the
template, maybe something like
lists/<list_id>/share
.
3. Then, our first unit test. It can be just enough to get a placeholder view in. We want
the view to respond to POST requests, and it should respond with a redirect back
to the list page, so the test could be called something like
ShareList
Test.test_post_redirects_to_lists_page
.
4. We build out our placeholder view, as just a two-liner that finds a list and redirects
to it.
5. We can then write a new unit test which creates a user and a list, does a POST with
their email address, and checks the user is added to
list_.shared_with.all()
(a
similar ORMusage to “My Lists”). That
shared_with
attribute won’t exist yet, we’re
going outside-in.
6. So before we can get this test to pass, we have to move down to the model layer.
The next test, in
test_models.py
, can check that a list has a
shared_with.add
method,
which can be called with a user’s email address and then check the lists’
shared_with.all()
queryset, which will subsequently contain that user.
7. You’ll then need a
ManyToManyField
. You’ll probably see an error message about a
clashing
related_name
, which you’ll find a solution to if you look around the
Django docs.
8. It will need a database migration.
9. That should get the model tests passing. Pop back up to fix the view test.
10. You may find the redirect view test fails, because it’s not sending a valid POST
request. You can either choose to ignore invalid inputs, or adjust the test to send a
valid POST.
11. Then back up to the template level; on the “My Lists” page we’ll want a
<ul>
with a
for loop of the lists shared with the user. On the lists page, we also want to show
who the list is shared with, as well as mention of who the list owner is. Look back
at the FT for the correct classes and IDs to use. You could have brief unit tests for
each of these if you like, as well.
12. You might find that spinning up the site with
runserver
will help you iron out any
bugs, as well as fine-tune the layout and aesthetics. If you use a private browser
session, you’ll be able to log multiple users in.
An Exercise for the Reader
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