Fixed #20000 -- Allowed ModelForm meta overrides for label, help_text and error_messages

django/forms/models.py

@@ -138,7 +138,9 @@ def model_to_dict(instance, fields=None, exclude=None):
             data[f.name] = f.value_from_object(instance)
     return data
 
-def fields_for_model(model, fields=None, exclude=None, widgets=None, formfield_callback=None, localized_fields=None):
+def fields_for_model(model, fields=None, exclude=None, widgets=None,
+                     formfield_callback=None, localized_fields=None,
+                     labels=None, help_texts=None, error_messages=None):
     """
     Returns a ``SortedDict`` containing form fields for the given model.
 
@@ -149,7 +151,16 @@ def fields_for_model(model, fields=None, exclude=None, widgets=None, formfield_c
     fields will be excluded from the returned fields, even if they are listed
     in the ``fields`` argument.
 
-    ``widgets`` is a dictionary of model field names mapped to a widget
+    ``widgets`` is a dictionary of model field names mapped to a widget.
+
+    ``localized_fields`` is a list of names of fields which should be localized.
+
+    ``labels`` is a dictionary of model field names mapped to a label.
+
+    ``help_texts`` is a dictionary of model field names mapped to a help text.
+
+    ``error_messages`` is a dictionary of model field names mapped to a
+    dictionary of error messages.
 
     ``formfield_callback`` is a callable that takes a model field and returns
     a form field.
@@ -170,6 +181,12 @@ def fields_for_model(model, fields=None, exclude=None, widgets=None, formfield_c
             kwargs['widget'] = widgets[f.name]
         if localized_fields == ALL_FIELDS or (localized_fields and f.name in localized_fields):
             kwargs['localize'] = True
+        if labels and f.name in labels:
+            kwargs['label'] = labels[f.name]
+        if help_texts and f.name in help_texts:
+            kwargs['help_text'] = help_texts[f.name]
+        if error_messages and f.name in error_messages:
+            kwargs['error_messages'] = error_messages[f.name]
 
         if formfield_callback is None:
             formfield = f.formfield(**kwargs)
@@ -197,6 +214,9 @@ class ModelFormOptions(object):
         self.exclude = getattr(options, 'exclude', None)
         self.widgets = getattr(options, 'widgets', None)
         self.localized_fields = getattr(options, 'localized_fields', None)
+        self.labels = getattr(options, 'labels', None)
+        self.help_texts = getattr(options, 'help_texts', None)
+        self.error_messages = getattr(options, 'error_messages', None)
 
 
 class ModelFormMetaclass(type):
@@ -248,7 +268,9 @@ class ModelFormMetaclass(type):
                 opts.fields = None
 
             fields = fields_for_model(opts.model, opts.fields, opts.exclude,
-                                      opts.widgets, formfield_callback, opts.localized_fields)
+                                      opts.widgets, formfield_callback,
+                                      opts.localized_fields, opts.labels,
+                                      opts.help_texts, opts.error_messages)
 
             # make sure opts.fields doesn't specify an invalid field
             none_model_fields = [k for k, v in six.iteritems(fields) if not v]
@@ -416,7 +438,8 @@ class ModelForm(six.with_metaclass(ModelFormMetaclass, BaseModelForm)):
     pass
 
 def modelform_factory(model, form=ModelForm, fields=None, exclude=None,
-                      formfield_callback=None, widgets=None, localized_fields=None):
+                      formfield_callback=None, widgets=None, localized_fields=None,
+                      labels=None, help_texts=None, error_messages=None):
     """
     Returns a ModelForm containing form fields for the given model.
 
@@ -434,6 +457,13 @@ def modelform_factory(model, form=ModelForm, fields=None, exclude=None,
 
     ``formfield_callback`` is a callable that takes a model field and returns
     a form field.
+
+    ``labels`` is a dictionary of model field names mapped to a label.
+
+    ``help_texts`` is a dictionary of model field names mapped to a help text.
+
+    ``error_messages`` is a dictionary of model field names mapped to a
+    dictionary of error messages.
     """
     # Create the inner Meta class. FIXME: ideally, we should be able to
     # construct a ModelForm without creating and passing in a temporary
@@ -449,6 +479,12 @@ def modelform_factory(model, form=ModelForm, fields=None, exclude=None,
         attrs['widgets'] = widgets
     if localized_fields is not None:
         attrs['localized_fields'] = localized_fields
+    if labels is not None:
+        attrs['labels'] = labels
+    if help_texts is not None:
+        attrs['help_texts'] = help_texts
+    if error_messages is not None:
+        attrs['error_messages'] = error_messages
 
     # If parent form class already has an inner Meta, the Meta we're
     # creating needs to inherit from the parent's inner meta.
@@ -738,7 +774,8 @@ class BaseModelFormSet(BaseFormSet):
 def modelformset_factory(model, form=ModelForm, formfield_callback=None,
                          formset=BaseModelFormSet, extra=1, can_delete=False,
                          can_order=False, max_num=None, fields=None, exclude=None,
-                         widgets=None, validate_max=False, localized_fields=None):
+                         widgets=None, validate_max=False, localized_fields=None,
+                         labels=None, help_texts=None, error_messages=None):
     """
     Returns a FormSet class for the given Django model class.
     """
@@ -759,7 +796,8 @@ def modelformset_factory(model, form=ModelForm, formfield_callback=None,
 
     form = modelform_factory(model, form=form, fields=fields, exclude=exclude,
                              formfield_callback=formfield_callback,
-                             widgets=widgets, localized_fields=localized_fields)
+                             widgets=widgets, localized_fields=localized_fields,
+                             labels=labels, help_texts=help_texts, error_messages=error_messages)
     FormSet = formset_factory(form, formset, extra=extra, max_num=max_num,
                               can_order=can_order, can_delete=can_delete,
                               validate_max=validate_max)
@@ -898,7 +936,8 @@ def inlineformset_factory(parent_model, model, form=ModelForm,
                           formset=BaseInlineFormSet, fk_name=None,
                           fields=None, exclude=None, extra=3, can_order=False,
                           can_delete=True, max_num=None, formfield_callback=None,
-                          widgets=None, validate_max=False, localized_fields=None):
+                          widgets=None, validate_max=False, localized_fields=None,
+                          labels=None, help_texts=None, error_messages=None):
     """
     Returns an ``InlineFormSet`` for the given kwargs.
 
@@ -922,6 +961,9 @@ def inlineformset_factory(parent_model, model, form=ModelForm,
         'widgets': widgets,
         'validate_max': validate_max,
         'localized_fields': localized_fields,
+        'labels': labels,
+        'help_texts': help_texts,
+        'error_messages': error_messages,
     }
     FormSet = modelformset_factory(model, **kwargs)
     FormSet.fk = fk

docs/ref/forms/models.txt

@@ -5,7 +5,7 @@ Model Form Functions
 .. module:: django.forms.models
    :synopsis: Django's functions for building model forms and formsets.
 
-.. function:: modelform_factory(model, form=ModelForm, fields=None, exclude=None, formfield_callback=None,  widgets=None, localized_fields=None)
+.. function:: modelform_factory(model, form=ModelForm, fields=None, exclude=None, formfield_callback=None, widgets=None, localized_fields=None, labels=None, help_texts=None, error_messages=None)
 
     Returns a :class:`~django.forms.ModelForm` class for the given ``model``.
     You can optionally pass a ``form`` argument to use as a starting point for
@@ -20,11 +20,18 @@ Model Form Functions
 
     ``widgets`` is a dictionary of model field names mapped to a widget.
 
-    ``localized_fields`` is a list of names of fields which should be localized.
-
     ``formfield_callback`` is a callable that takes a model field and returns
     a form field.
 
+    ``localized_fields`` is a list of names of fields which should be localized.
+
+    ``labels`` is a dictionary of model field names mapped to a label.
+
+    ``help_texts`` is a dictionary of model field names mapped to a help text.
+
+    ``error_messages`` is a dictionary of model field names mapped to a
+    dictionary of error messages.
+
     See :ref:`modelforms-factory` for example usage.
 
     .. versionchanged:: 1.6
@@ -35,14 +42,16 @@ Model Form Functions
     information. Omitting any definition of the fields to use will result in all
     fields being used, but this behavior is deprecated.
 
-    The ``localized_fields`` parameter was added.
+    The ``localized_fields``, ``labels``, ``help_texts``, and
+    ``error_messages`` parameters were added.
 
-.. function:: modelformset_factory(model, form=ModelForm, formfield_callback=None, formset=BaseModelFormSet, extra=1, can_delete=False, can_order=False, max_num=None, fields=None, exclude=None, widgets=None, validate_max=False, localized_fields=None)
+.. function:: modelformset_factory(model, form=ModelForm, formfield_callback=None, formset=BaseModelFormSet, extra=1, can_delete=False, can_order=False, max_num=None, fields=None, exclude=None, widgets=None, validate_max=False, localized_fields=None, labels=None, help_texts=None, error_messages=None)
 
     Returns a ``FormSet`` class for the given ``model`` class.
 
     Arguments ``model``, ``form``, ``fields``, ``exclude``,
-    ``formfield_callback``, ``widgets`` and ``localized_fields`` are all passed through to
+    ``formfield_callback``, ``widgets``, ``localized_fields``, ``labels``,
+    ``help_texts``, and ``error_messages`` are all passed through to
     :func:`~django.forms.models.modelform_factory`.
 
     Arguments ``formset``, ``extra``, ``max_num``, ``can_order``,
@@ -54,9 +63,10 @@ Model Form Functions
 
     .. versionchanged:: 1.6
 
-        The ``widgets``, ``validate_max`` and ``localized_fields`` parameters were added.
+        The ``widgets``, ``validate_max``, ``localized_fields``, ``labels``,
+        ``help_texts``, and ``error_messages`` parameters were added.
 
-.. function:: inlineformset_factory(parent_model, model, form=ModelForm, formset=BaseInlineFormSet, fk_name=None, fields=None, exclude=None, extra=3, can_order=False, can_delete=True, max_num=None, formfield_callback=None, widgets=None, validate_max=False, localized_fields=None)
+.. function:: inlineformset_factory(parent_model, model, form=ModelForm, formset=BaseInlineFormSet, fk_name=None, fields=None, exclude=None, extra=3, can_order=False, can_delete=True, max_num=None, formfield_callback=None, widgets=None, validate_max=False, localized_fields=None, labels=None, help_texts=None, error_messages=None)
 
     Returns an ``InlineFormSet`` using :func:`modelformset_factory` with
     defaults of ``formset=BaseInlineFormSet``, ``can_delete=True``, and
@@ -69,4 +79,5 @@ Model Form Functions
 
     .. versionchanged:: 1.6
 
-        The ``widgets``, ``validate_max`` and ``localized_fields`` parameters were added.
+        The ``widgets``, ``validate_max`` and ``localized_fields``, ``labels``,
+        ``help_texts``, and ``error_messages`` parameters were added.

docs/releases/1.6.txt

@@ -236,9 +236,14 @@ Minor features
 .. _`Pillow`: https://pypi.python.org/pypi/Pillow
 .. _`PIL`: https://pypi.python.org/pypi/PIL
 
-* :doc:`ModelForm </topics/forms/modelforms/>` accepts a new
-  Meta option: ``localized_fields``. Fields included in this list will be localized
-  (by setting ``localize`` on the form field).
+* :class:`~django.forms.ModelForm` accepts several new ``Meta``
+  options.
+
+  * Fields included in the ``localized_fields`` list will be localized
+    (by setting ``localize`` on the form field).
+  * The  ``labels``, ``help_texts`` and ``error_messages`` options may be used
+    to customize the default fields, see
+    :ref:`modelforms-overriding-default-fields` for details.
 
 * The ``choices`` argument to model fields now accepts an iterable of iterables
   instead of requiring an iterable of lists or tuples.

docs/topics/forms/modelforms.txt

@@ -141,7 +141,7 @@ In addition, each generated form field has attributes set as follows:
   ``default`` value will be initially selected instead).
 
 Finally, note that you can override the form field used for a given model
-field. See `Overriding the default field types or widgets`_ below.
+field. See `Overriding the default fields`_ below.
 
 A full example
 --------------
@@ -388,8 +388,10 @@ include that field.
 
 .. _section on saving forms: `The save() method`_
 
-Overriding the default field types or widgets
----------------------------------------------
+.. _modelforms-overriding-default-fields:
+
+Overriding the default fields
+-----------------------------
 
 The default field types, as described in the `Field types`_ table above, are
 sensible defaults. If you have a ``DateField`` in your model, chances are you'd
@@ -420,38 +422,65 @@ widget::
 The ``widgets`` dictionary accepts either widget instances (e.g.,
 ``Textarea(...)``) or classes (e.g., ``Textarea``).
 
-If you want to further customize a field -- including its type, label, etc. --
-you can do this by declaratively specifying fields like you would in a regular
-``Form``. Declared fields will override the default ones generated by using the
-``model`` attribute.
+.. versionadded:: 1.6
+
+    The ``labels``, ``help_texts`` and ``error_messages`` options were added.
+
+Similarly, you can specify the ``labels``, ``help_texts`` and ``error_messages``
+attributes of the inner ``Meta`` class if you want to further customize a field.
 
-For example, if you wanted to use ``MyDateFormField`` for the ``pub_date``
+For example if you wanted to customize the wording of all user facing strings for
+the ``name`` field::
+
+    class AuthorForm(ModelForm):
+        class Meta:
+            model = Author
+            fields = ('name', 'title', 'birth_date')
+            labels = {
+                'name': _('Writer'),
+            }
+            help_texts = {
+                'name': _('Some useful help text.'),
+            }
+            error_messages = {
+                'name': {
+                    'max_length': _("This writer's name is too long."),
+                },
+            }
+
+Finally, if you want complete control over of a field -- including its type,
+validators, etc. -- you can do this by declaratively specifying fields like you
+would in a regular ``Form``. Declared fields will override the default ones
+generated by using the ``model`` attribute. Fields declared like this will
+ignore any customizations in the ``widgets``, ``labels``, ``help_texts``, and
+``error_messages`` options declared on ``Meta``.
+
+For example, if you wanted to use ``MySlugFormField`` for the ``slug``
 field, you could do the following::
 
     from django.forms import ModelForm
     from myapp.models import Article
 
     class ArticleForm(ModelForm):
-        pub_date = MyDateFormField()
+        slug = MySlugFormField()
 
         class Meta:
             model = Article
             fields = ['pub_date', 'headline', 'content', 'reporter']
 
 
-If you want to override a field's default label, then specify the ``label``
-parameter when declaring the form field::
+If you want to override a field's default validators, then specify the
+``validators`` parameter when declaring the form field::
 
     from django.forms import ModelForm, DateField
     from myapp.models import Article
 
     class ArticleForm(ModelForm):
-        pub_date = DateField(label='Publication date')
+        slug = CharField(validators=[validate_slug])
 
         class Meta:
             model = Article
-            fields = ['pub_date', 'headline', 'content', 'reporter']
-
+            fields = ['pub_date', 'headline', 'content', 'reporter', 'slug']
 
 .. note::
 
@@ -597,7 +626,7 @@ example by specifying the widgets to be used for a given field::
 
     >>> from django.forms import Textarea
     >>> Form = modelform_factory(Book, form=BookForm,
-                                 widgets={"title": Textarea()})
+    ...                          widgets={"title": Textarea()})
 
 The fields to include can be specified using the ``fields`` and ``exclude``
 keyword arguments, or the corresponding attributes on the ``ModelForm`` inner

tests/model_forms/tests.py

@@ -490,7 +490,7 @@ class ModelFormBaseTest(TestCase):
                          ['slug', 'name'])
 
 
-class TestWidgetForm(forms.ModelForm):
+class FieldOverridesTroughFormMetaForm(forms.ModelForm):
     class Meta:
         model = Category
         fields = ['name', 'url', 'slug']
@@ -498,25 +498,74 @@ class TestWidgetForm(forms.ModelForm):
             'name': forms.Textarea,
             'url': forms.TextInput(attrs={'class': 'url'})
         }
+        labels = {
+            'name': 'Title',
+        }
+        help_texts = {
+            'slug': 'Watch out! Letters, numbers, underscores and hyphens only.',
+        }
+        error_messages = {
+            'slug': {
+                'invalid': (
+                    "Didn't you read the help text? "
+                    "We said letters, numbers, underscores and hyphens only!"
+                )
+            }
+        }
 
 
+class TestFieldOverridesTroughFormMeta(TestCase):
+    def test_widget_overrides(self):
+        form = FieldOverridesTroughFormMetaForm()
+        self.assertHTMLEqual(
+            str(form['name']),
+            '<textarea id="id_name" rows="10" cols="40" name="name"></textarea>',
+        )
+        self.assertHTMLEqual(
+            str(form['url']),
+            '<input id="id_url" type="text" class="url" name="url" maxlength="40" />',
+        )
+        self.assertHTMLEqual(
+            str(form['slug']),
+            '<input id="id_slug" type="text" name="slug" maxlength="20" />',
+        )
 
-class TestWidgets(TestCase):
-    def test_base_widgets(self):
-        frm = TestWidgetForm()
+    def test_label_overrides(self):
+        form = FieldOverridesTroughFormMetaForm()
         self.assertHTMLEqual(
-            str(frm['name']),
-            '<textarea id="id_name" rows="10" cols="40" name="name"></textarea>'
+            str(form['name'].label_tag()),
+            '<label for="id_name">Title:</label>',
         )
         self.assertHTMLEqual(
-            str(frm['url']),
-            '<input id="id_url" type="text" class="url" name="url" maxlength="40" />'
+            str(form['url'].label_tag()),
+            '<label for="id_url">The URL:</label>',
         )
         self.assertHTMLEqual(
-            str(frm['slug']),
-            '<input id="id_slug" type="text" name="slug" maxlength="20" />'
+            str(form['slug'].label_tag()),
+            '<label for="id_slug">Slug:</label>',
         )
 
+    def test_help_text_overrides(self):
+        form = FieldOverridesTroughFormMetaForm()
+        self.assertEqual(
+            form['slug'].help_text,
+            'Watch out! Letters, numbers, underscores and hyphens only.',
+        )
+
+    def test_error_messages_overrides(self):
+        form = FieldOverridesTroughFormMetaForm(data={
+            'name': 'Category',
+            'url': '/category/',
+            'slug': '!%#*@',
+        })
+        form.full_clean()
+
+        error = [
+            "Didn't you read the help text? "
+            "We said letters, numbers, underscores and hyphens only!",
+        ]
+        self.assertEqual(form.errors, {'slug': error})
+
 
 class IncompleteCategoryFormWithFields(forms.ModelForm):
     """

tests/model_formsets/tests.py

@@ -1261,7 +1261,7 @@ class ModelFormsetTest(TestCase):
             ['Please correct the duplicate data for subtitle which must be unique for the month in posted.'])
 
 
-class TestModelFormsetWidgets(TestCase):
+class TestModelFormsetOverridesTroughFormMeta(TestCase):
     def test_modelformset_factory_widgets(self):
         widgets = {
             'name': forms.TextInput(attrs={'class': 'poet'})
@@ -1283,3 +1283,53 @@ class TestModelFormsetWidgets(TestCase):
             "%s" % form['title'],
             '<input class="book" id="id_title" maxlength="100" name="title" type="text" />'
         )
+
+    def test_modelformset_factory_labels_overrides(self):
+        BookFormSet = modelformset_factory(Book, fields="__all__", labels={
+            'title': 'Name'
+        })
+        form = BookFormSet.form()
+        self.assertHTMLEqual(form['title'].label_tag(), '<label for="id_title">Name:</label>')
+
+    def test_inlineformset_factory_labels_overrides(self):
+        BookFormSet = inlineformset_factory(Author, Book, fields="__all__", labels={
+            'title': 'Name'
+        })
+        form = BookFormSet.form()
+        self.assertHTMLEqual(form['title'].label_tag(), '<label for="id_title">Name:</label>')
+
+    def test_modelformset_factory_help_text_overrides(self):
+        BookFormSet = modelformset_factory(Book, fields="__all__", help_texts={
+            'title': 'Choose carefully.'
+        })
+        form = BookFormSet.form()
+        self.assertEqual(form['title'].help_text, 'Choose carefully.')
+
+    def test_inlineformset_factory_help_text_overrides(self):
+        BookFormSet = inlineformset_factory(Author, Book, fields="__all__", help_texts={
+            'title': 'Choose carefully.'
+        })
+        form = BookFormSet.form()
+        self.assertEqual(form['title'].help_text, 'Choose carefully.')
+
+    def test_modelformset_factory_error_messages_overrides(self):
+        author = Author.objects.create(pk=1, name='Charles Baudelaire')
+        BookFormSet = modelformset_factory(Book, fields="__all__", error_messages={
+            'title': {
+                'max_length': 'Title too long!!'
+            }
+        })
+        form = BookFormSet.form(data={'title': 'Foo ' * 30, 'author': author.id})
+        form.full_clean()
+        self.assertEqual(form.errors, {'title': ['Title too long!!']})
+
+    def test_inlineformset_factory_error_messages_overrides(self):
+        author = Author.objects.create(pk=1, name='Charles Baudelaire')
+        BookFormSet = inlineformset_factory(Author, Book, fields="__all__", error_messages={
+            'title': {
+                'max_length': 'Title too long!!'
+            }
+        })
+        form = BookFormSet.form(data={'title': 'Foo ' * 30, 'author': author.id})
+        form.full_clean()
+        self.assertEqual(form.errors, {'title': ['Title too long!!']})