diff options
| -rw-r--r-- | docs/topics/forms/modelforms.txt | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/docs/topics/forms/modelforms.txt b/docs/topics/forms/modelforms.txt index add581268b..3a0c2d175c 100644 --- a/docs/topics/forms/modelforms.txt +++ b/docs/topics/forms/modelforms.txt @@ -371,6 +371,35 @@ parameter when declaring the form field:: ... class Meta: ... model = Article +.. note:: + + If you explicitly instantiate a form field like this, Django assumes that you + want to completely define its behavior; therefore, default attributes (such as + ``max_length`` or ``required``) are not drawn from the corresponding model. If + you want to maintain the behavior specified in the model, you must set the + relevant arguments explicitly when declaring the form field. + + For example, if the ``Article`` model looks like this:: + + class Article(models.Model): + headline = models.CharField(max_length=200, null=True, blank=True, + help_text="Use puns liberally") + content = models.TextField() + + and you want to do some custom validation for ``headline``, while keeping + the ``blank`` and ``help_text`` values as specified, you might define + ``ArticleForm`` like this:: + + class ArticleForm(ModelForm): + headline = MyFormField(max_length=200, required=False, + help_text="Use puns liberally") + + class Meta: + model = Article + + See the :ref:`form field documentation <ref-forms-fields>` for more information + on fields and their arguments. + Changing the order of fields ---------------------------- |