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self
.
instance
.
validate_unique
()
except
ValidationError
as
e
:
e
.
error_dict
=
{
'text'
: [
DUPLICATE_ITEM_ERROR
]}
self
.
_update_errors
(
e
)
That’s a bit of Django voodoo right there, but we basically take the validation error,
adjust its error message, and then pass it back into the form. And we’re there! A quick
commit:
$
git diff
$
git commit -a
Using the Existing List Item Form in the List View
Now let’s see if we can put this form to work in our view.
We remove the skip, and while we’re at it, we can use our new constant. Tidy.
lists/tests/test_views.py (ch12l049).
from
lists.forms
import
(
DUPLICATE_ITEM_ERROR
,
EMPTY_LIST_ERROR
,
ExistingListItemForm
,
ItemForm
,
)
[
...
]
def
test_duplicate_item_validation_errors_end_up_on_lists_page
(
self
):
[
...
]
expected_error
=
escape
(
DUPLICATE_ITEM_ERROR
)
That brings back out integrity error:
django.db.utils.IntegrityError: UNIQUE constraint failed: lists_item.list_id,
lists_item.text
Our fix for this is to switch to using the new form class. Before we implement it, let’s
find the tests where we check the form class, and adjust them:
lists/tests/test_views.py (ch12l050).
class
ListViewTest
(
TestCase
):
[
...
]
def
test_displays_item_form
(
self
):
list_
=
List
.
objects
.
create
()
response
=
self
.
client
.
get
(
'/lists/
%d
/'
%
(
list_
.
id
,))
self
.
assertIsInstance
(
response
.
context
[
'form'
],
ExistingListItemForm
)
self
.
assertContains
(
response
,
'name="text"'
)
[
...
]
def
test_for_invalid_input_passes_form_to_template
(
self
):
response
=
self
.
post_invalid_input
()
self
.
assertIsInstance
(
response
.
context
[
'form'
],
ExistingListItemForm
)
That gives us:
Using the Existing List Item Form in the List View
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221