From 5b26a014a81ba0d404d46e11d2b45c01d92b97e5 Mon Sep 17 00:00:00 2001
From: Alasdair Nicol <alasdair@thenicols.net>
Date: Tue, 18 Nov 2014 17:58:43 +0000
Subject: [PATCH] Fixed #23865 -- documented how to assign errors to a field in
Model.clean()
Also added a unit test wit the simpler syntax which we have documented,
where the dictionary values are strings.
---
docs/ref/models/instances.txt | 20 +++++++++++++++++---
tests/model_forms/models.py | 2 ++
tests/model_forms/tests.py | 7 +++++++
3 files changed, 26 insertions(+), 3 deletions(-)
diff --git a/docs/ref/models/instances.txt b/docs/ref/models/instances.txt
index 21c4c86c13..4e8a1d1ee8 100644
--- a/docs/ref/models/instances.txt
+++ b/docs/ref/models/instances.txt
@@ -200,9 +200,10 @@ access to more than a single field::
Note, however, that like :meth:`Model.full_clean()`, a model's ``clean()``
method is not invoked when you call your model's :meth:`~Model.save()` method.
-Any :exc:`~django.core.exceptions.ValidationError` exceptions raised by
-``Model.clean()`` will be stored in a special key error dictionary key,
-:data:`~django.core.exceptions.NON_FIELD_ERRORS`, that is used for errors
+In the above example, the :exc:`~django.core.exceptions.ValidationError`
+exception raised by ``Model.clean()`` was instantiated with a string, so it
+will be stored in a special error dictionary key,
+:data:`~django.core.exceptions.NON_FIELD_ERRORS`. This key is used for errors
that are tied to the entire model instead of to a specific field::
from django.core.exceptions import ValidationError, NON_FIELD_ERRORS
@@ -211,6 +212,19 @@ that are tied to the entire model instead of to a specific field::
except ValidationError as e:
non_field_errors = e.message_dict[NON_FIELD_ERRORS]
+To assign exceptions to a specific field, instantiate the
+:exc:`~django.core.exceptions.ValidationError` with a dictionary, where the
+keys are the field names. We could update the previous example to assign the
+error to the ``pub_date`` field::
+
+ class Article(models.Model):
+ ...
+ def clean(self):
+ # Don't allow draft entries to have a pub_date.
+ if self.status == 'draft' and self.pub_date is not None:
+ raise ValidationError({'pub_date': 'Draft entries may not have a publication date.'})
+ ...
+
Finally, ``full_clean()`` will check any unique constraints on your model.
.. method:: Model.validate_unique(exclude=None)
diff --git a/tests/model_forms/models.py b/tests/model_forms/models.py
index 1b5ae90b07..4ab681d1ae 100644
--- a/tests/model_forms/models.py
+++ b/tests/model_forms/models.py
@@ -381,6 +381,8 @@ class CustomErrorMessage(models.Model):
def clean(self):
if self.name1 == 'FORBIDDEN_VALUE':
raise ValidationError({'name1': [ValidationError('Model.clean() error messages.')]})
+ elif self.name1 == 'FORBIDDEN_VALUE2':
+ raise ValidationError({'name1': 'Model.clean() error messages (simpler syntax).'})
elif self.name1 == 'GLOBAL_ERROR':
raise ValidationError("Global error message.")
diff --git a/tests/model_forms/tests.py b/tests/model_forms/tests.py
index 962e5b969f..4ff900e1b2 100644
--- a/tests/model_forms/tests.py
+++ b/tests/model_forms/tests.py
@@ -2269,6 +2269,13 @@ class ModelFormCustomErrorTests(TestCase):
str(form.errors['name1']),
'<ul class="errorlist"><li>Model.clean() error messages.</li></ul>'
)
+ data = {'name1': 'FORBIDDEN_VALUE2', 'name2': 'ABC'}
+ form = CustomErrorMessageForm(data)
+ self.assertFalse(form.is_valid())
+ self.assertHTMLEqual(
+ str(form.errors['name1']),
+ '<ul class="errorlist"><li>Model.clean() error messages (simpler syntax).</li></ul>'
+ )
data = {'name1': 'GLOBAL_ERROR', 'name2': 'ABC'}
form = CustomErrorMessageForm(data)
self.assertFalse(form.is_valid())