Ticket #6162: modelform-init-2.diff

django/newforms/models.py

@@ -262 +262 @@
-        return type.__new__(cls, name, bases, attrs)
-
-class BaseModelForm(BaseForm):
-
-
-
+
+
-        opts = self._meta
-
+
+
+
+
+
+
+
+
-        # if initial was provided, it should override the values from instance
-        if initial is not None:
-            object_data.update(initial)

tests/modeltests/model_forms/models.py

@@ -29 +29 @@
-    def __unicode__(self):
-        return self.name
-
+class Editor(models.Model):
+    name = models.CharField(max_length=50, help_text='Use both first and last names.')
+    categories = models.ManyToManyField(Category)
+
+    def __unicode__(self):
+        return self.name
+
-class Article(models.Model):
-    headline = models.CharField(max_length=50)
-    slug = models.SlugField()
@@ -155 +162 @@
-...
-ImproperlyConfigured: BadForm's base classes define more than one model.
-
+Require either a model bound in Meta or an instance passed in on __init__().
-
-
+
+
-
+>>> f = NoModelForm()
+Traceback (most recent call last):
+...
+ImproperlyConfigured: ModelForm must either be bound to a model class or receive a model instance in __init__()
+
+# Test valid ModelForms #######################################################
+
->>> from django.newforms import ModelForm, CharField
->>> import datetime
-
@@ -167 +183 @@
->>> class CategoryForm(ModelForm):
-...     class Meta:
-...         model = Category
-Category()
+
->>> print f
-<tr><th><label for="id_name">Name:</label></th><td><input id="id_name" type="text" name="name" maxlength="20" /></td></tr>
-<tr><th><label for="id_slug">Slug:</label></th><td><input id="id_slug" type="text" name="slug" maxlength="20" /></td></tr>
@@ -179 +195 @@
->>> print f['name']
-<input id="id_name" type="text" name="name" maxlength="20" />
-
-Category(), 
+
->>> print f.as_ul()
-<li>Name: <input type="text" name="name" maxlength="20" /></li>
-<li>Slug: <input type="text" name="slug" maxlength="20" /></li>
-<li>The URL: <input type="text" name="url" maxlength="40" /></li>
-
-Category(), 
+
->>> f.is_valid()
-True
->>> f.cleaned_data
@@ -196 +212 @@
->>> Category.objects.all()
-[<Category: Entertainment>]
-
-Category(), 
+
->>> f.is_valid()
-True
->>> f.cleaned_data
@@ -210 +226 @@
-If you call save() with commit=False, then it will return an object that
-hasn't yet been saved to the database. In this case, it's up to you to call
-save() on the resulting model instance.
-Category(), 
+
->>> f.is_valid()
-True
->>> f.cleaned_data
@@ -225 +241 @@
-[<Category: Entertainment>, <Category: It's a test>, <Category: Third test>]
-
-If you call save() with invalid data, you'll get a ValueError.
-Category(), 
+
->>> f.errors
-{'name': [u'This field is required.'], 'slug': [u'This field is required.']}
->>> f.cleaned_data
@@ -236 +252 @@
-Traceback (most recent call last):
-...
-ValueError: The Category could not be created because the data didn't validate.
-Category(), 
+
->>> f.save()
-Traceback (most recent call last):
-...
@@ -253 +269 @@
->>> class ArticleForm(ModelForm):
-...     class Meta:
-...         model = Article
-Article(), 
+
->>> print f
-<tr><th>Headline:</th><td><input type="text" name="headline" maxlength="50" /></td></tr>
-<tr><th>Slug:</th><td><input type="text" name="slug" maxlength="50" /></td></tr>
@@ -286 +302 @@
-...     class Meta:
-...         model = Article
-...         fields = ('headline','pub_date')
-Article(), 
+
->>> print f
-<tr><th>Headline:</th><td><input type="text" name="headline" maxlength="50" /></td></tr>
-<tr><th>Pub date:</th><td><input type="text" name="pub_date" /></td></tr>
-
-Use form_for_instance to create a Form from a model instance. The differenc
-between this Form and one created via form_for_model
+Pass the "instance" keyword argument to create a Form from a model instance. Th
+difference between this Form and one created wthout the"instance" argument
-current values are inserted as 'initial' data in each Field.
->>> w = Writer.objects.get(name='Mike Royko')
->>> class RoykoForm(ModelForm):
-...     class Meta:
-...         model = Writer
-w, auto_id=False
+auto_id=False, instance=w
->>> print f
-<tr><th>Name:</th><td><input type="text" name="name" value="Mike Royko" maxlength="50" /><br />Use both first and last names.</td></tr>
-
@@ -309 +325 @@
->>> class TestArticleForm(ModelForm):
-...     class Meta:
-...         model = Article
-
+instance=
->>> print f.as_ul()
-<li>Headline: <input type="text" name="headline" value="Test article" maxlength="50" /></li>
-<li>Slug: <input type="text" name="slug" value="test-article" maxlength="50" /></li>
@@ -331 +347 @@
-<option value="2">It&#39;s a test</option>
-<option value="3">Third test</option>
-</select>  Hold down "Control", or "Command" on a Mac, to select more than one.</li>
-art, {'headline': u'Test headline', 'slug': 'test-headline', 'pub_date': u'1984-02-06', 'writer': u'1', 'article': 'Hello.'}
+{'headline': u'Test headline', 'slug': 'test-headline', 'pub_date': u'1984-02-06', 'writer': u'1', 'article': 'Hello.'}, instance=art
->>> f.is_valid()
-True
->>> test_art = f.save()
@@ -347 +363 @@
-...     class Meta:
-...         model = Article
-...         fields=('headline', 'slug', 'pub_date')
-art, {'headline': u'New headline', 'slug': 'new-headline', 'pub_date': u'1988-01-04'}, auto_id=False
+{'headline': u'New headline', 'slug': 'new-headline', 'pub_date': u'1988-01-04'}, auto_id=False, instance=art
->>> print f.as_ul()
-<li>Headline: <input type="text" name="headline" value="New headline" maxlength="50" /></li>
-<li>Slug: <input type="text" name="slug" value="new-headline" maxlength="50" /></li>
@@ -370 +386 @@
->>> class TestArticleForm(ModelForm):
-...     class Meta:
-...         model = Article
-new_art, auto_id=False
+auto_id=False, instance=new_art
->>> print f.as_ul()
-<li>Headline: <input type="text" name="headline" value="New headline" maxlength="50" /></li>
-<li>Slug: <input type="text" name="slug" value="new-headline" maxlength="50" /></li>
@@ -393 +409 @@
-<option value="3">Third test</option>
-</select>  Hold down "Control", or "Command" on a Mac, to select more than one.</li>
-
-new_art, 
-
+
+, instance=new_art
->>> new_art = f.save()
->>> new_art.id
-1
@@ -403 +419 @@
-[<Category: Entertainment>, <Category: It's a test>]
-
-Now, submit form data with no categories. This deletes the existing categories.
-new_art, 
-
+
+, instance=new_art
->>> new_art = f.save()
->>> new_art.id
-1
@@ -416 +432 @@
->>> class ArticleForm(ModelForm):
-...     class Meta:
-...         model = Article
-Article(), 
+
-...     'writer': u'1', 'article': u'Test.', 'categories': [u'1', u'2']})
->>> new_art = f.save()
->>> new_art.id
@@ -429 +445 @@
->>> class ArticleForm(ModelForm):
-...     class Meta:
-...         model = Article
-Article(), 
+
-...     'writer': u'1', 'article': u'Test.'})
->>> new_art = f.save()
->>> new_art.id
@@ -443 +459 @@
->>> class ArticleForm(ModelForm):
-...     class Meta:
-...         model = Article
-Article(), 
+
-...     'writer': u'1', 'article': u'Test.', 'categories': [u'1', u'2']})
->>> new_art = f.save(commit=False)
-
@@ -474 +490 @@
-<Category: Third test>
->>> cat.id
-3
-cat, {'name': 'Third', 'slug': 'third', 'url': '3rd'}
+{'name': 'Third', 'slug': 'third', 'url': '3rd'}, instance=cat
->>> form.save()
-<Category: Third>
->>> Category.objects.get(id=3)
@@ -486 +502 @@
->>> class ArticleForm(ModelForm):
-...     class Meta:
-...         model = Article
-Article(), 
+
->>> print f.as_ul()
-<li>Headline: <input type="text" name="headline" maxlength="50" /></li>
-<li>Slug: <input type="text" name="slug" maxlength="50" /></li>
@@ -536 +552 @@
-<option value="4">Fourth</option>
-</select>  Hold down "Control", or "Command" on a Mac, to select more than one.</li>
-
+By not binding the form to a specific model, and by explicitly
+specifying a list of fields, it's possible to use a ModelForm with any
+model which has fields of those names. Doing so requires that an
+instance be passed in on form instantiation.
+
+>>> class WriterOrEditorForm(ModelForm):
+...     name = forms.CharField(max_length=50)
+>>> w = Writer()
+>>> f = WriterOrEditorForm(instance=w)
+>>> print f.as_ul()
+<li><label for="id_name">Name:</label> <input id="id_name" type="text" name="name" maxlength="50" /></li>
+>>> e = Editor(name="Horace Greeley")
+>>> f = WriterOrEditorForm(instance=e)
+>>> print f.as_ul()
+<li><label for="id_name">Name:</label> <input id="id_name" type="text" name="name" value="Horace Greeley" maxlength="50" /></li>
+
+
-# ModelChoiceField ############################################################
-
->>> from django.newforms import ModelChoiceField, ModelMultipleChoiceField
@@ -690 +723 @@
->>> class PhoneNumberForm(ModelForm):
-...     class Meta:
-...         model = PhoneNumber
-PhoneNumber(), 
+
->>> f.is_valid()
-True
->>> f.cleaned_data

docs/modelforms.txt

@@ -24 +24 @@
-    ...         model = Article
-
-    # Creating a form to add an article.
-
-
+
-
-    # Creating a form to change an existing article.
-    >>> article = Article.objects.get(pk=1)
-
+instance=
-
-Field types
------------
@@ -166 +165 @@
-The ``save()`` method
----------------------
-
-
-
-
-
+
+
+
+
+
+
-
-    # Create a form instance from POST data.
-
-
+
-
-    # Save a new Article object from the form's data.
-    >>> new_article = f.save()
-
+    # Create a form to edit an existing Article.
+    >>> a = Article.objects.get(pk=1)
+    >>> f = ArticleForm(instance=a)
+
-Note that ``save()`` will raise a ``ValueError`` if the data in the form
-doesn't validate -- i.e., ``if form.errors``.
-
@@ -201 +205 @@
-``save_m2m()`` to save the many-to-many form data. For example::
-
-    # Create a form instance with POST data.
-
-
+
-
-    # Create, but don't save the new author instance.
-    >>> new_author = f.save(commit=False)
@@ -222 +225 @@
-For example::
-
-    # Create a form instance with POST data.
-
-
+
-
-    # Create and save the new author instance. There's no need to do anything else.
-    >>> new_author = f.save()
@@ -277 +279 @@
-    manually set anyextra required fields::
-    
-        instance = Instance(required_field='value')
-instance, request.POST
+request.POST, instance=instance
-        new_instance = form.save()
-
-        instance = form.save(commit=False)
@@ -289 +291 @@
-
-.. _section on saving forms: `The save() method`_
-
+Using a form with any of multiple models
+----------------------------------------
+
+If you have several models which share a common set of fields, and
+want to expose just those fields for editing, you can define a
+``ModelForm`` subclass *without* specifying the model, and list only
+the shared fields to be displayed.
+
+For example, if your application has multiple models which represent
+different types of people, each with a "name" field, you could define
+a ``ModelForm`` subclass like so::
+
+    from django import newforms as forms
+
+    class PersonNameForm(forms.ModelForm):
+        name = forms.CharField(max_length=50)
+
+You could then pass any instance of any model which has a "name" field
+as the ``instance`` keyword argument when creating an instance of the
+form.
+
+Note that when a ``ModelForm`` is used like this, two important
+restrictions apply:
+
+1. Only the fields which are explicitly declared on the form will be
+   displayed.
+
+2. It is your responsibility to supply values for any other required
+   fields before saving the model instance, either by filling them in
+   on the instance before passing it to the form, or by using the
+   ``commit=False`` argument to ``save()`` and then filling in the
+   fields before actually saving the instance to the databae.
+        
+Defining a ``ModelForm`` subclass without specifying a model, and then
+attempting to instantiate it without passing a model instance as the
+``instance`` keyword argument, is an error.
+
+
-Overriding the default field types
-----------------------------------
-