""" XX. Generating HTML forms from models This is mostly just a reworking of the form_for_model/form_for_instance tests to use ModelForm. As such, the text may not make sense in all cases, and the examples are probably a poor fit for the ModelForm syntax. In other words, most of these tests should be rewritten. """ from django.db import models ARTICLE_STATUS = ( (1, 'Draft'), (2, 'Pending'), (3, 'Live'), ) class Category(models.Model): name = models.CharField(max_length=20) slug = models.SlugField(max_length=20) url = models.CharField('The URL', max_length=40) def __unicode__(self): return self.name class Writer(models.Model): name = models.CharField(max_length=50, help_text='Use both first and last names.') def __unicode__(self): return self.name class Article(models.Model): headline = models.CharField(max_length=50) slug = models.SlugField() pub_date = models.DateField() created = models.DateField(editable=False) writer = models.ForeignKey(Writer) article = models.TextField() categories = models.ManyToManyField(Category, blank=True) status = models.IntegerField(choices=ARTICLE_STATUS, blank=True, null=True) def save(self): import datetime if not self.id: self.created = datetime.date.today() return super(Article, self).save() def __unicode__(self): return self.headline class PhoneNumber(models.Model): phone = models.PhoneNumberField() description = models.CharField(max_length=20) def __unicode__(self): return self.phone __test__ = {'API_TESTS': """ >>> from django import newforms as forms >>> from django.newforms.models import ModelForm The bare bones, absolutely nothing custom, basic case. >>> class CategoryForm(ModelForm): ... class Meta: ... model = Category >>> CategoryForm.base_fields.keys() ['name', 'slug', 'url'] Extra fields. >>> class CategoryForm(ModelForm): ... some_extra_field = forms.BooleanField() ... ... class Meta: ... model = Category >>> CategoryForm.base_fields.keys() ['name', 'slug', 'url', 'some_extra_field'] Replacing a field. >>> class CategoryForm(ModelForm): ... url = forms.BooleanField() ... ... class Meta: ... model = Category >>> CategoryForm.base_fields['url'].__class__ Using 'fields'. >>> class CategoryForm(ModelForm): ... ... class Meta: ... model = Category ... fields = ['url'] >>> CategoryForm.base_fields.keys() ['url'] Using 'exclude' >>> class CategoryForm(ModelForm): ... ... class Meta: ... model = Category ... exclude = ['url'] >>> CategoryForm.base_fields.keys() ['name', 'slug'] Using 'fields' *and* 'exclude'. Not sure why you'd want to do this, but uh, "be liberal in what you accept" and all. >>> class CategoryForm(ModelForm): ... ... class Meta: ... model = Category ... fields = ['name', 'url'] ... exclude = ['url'] >>> CategoryForm.base_fields.keys() ['name'] Don't allow more than one 'model' definition in the inheritance hierarchy. Technically, it would generate a valid form, but the fact that the resulting save method won't deal with multiple objects is likely to trip up people not familiar with the mechanics. >>> class CategoryForm(ModelForm): ... class Meta: ... model = Category >>> class BadForm(CategoryForm): ... class Meta: ... model = Article Traceback (most recent call last): ... ImproperlyConfigured: BadForm defines more than one model. >>> class ArticleForm(ModelForm): ... class Meta: ... model = Article >>> class BadForm(ArticleForm, CategoryForm): ... pass Traceback (most recent call last): ... ImproperlyConfigured: BadForm's base classes define more than one model. # Old form_for_x tests ####################################################### >>> from django.newforms import ModelForm, CharField >>> import datetime >>> Category.objects.all() [] >>> class CategoryForm(ModelForm): ... class Meta: ... model = Category >>> f = CategoryForm() >>> print f >>> print f.as_ul()
  • >>> print f['name'] >>> f = CategoryForm(auto_id=False) >>> print f.as_ul()
  • Name:
  • Slug:
  • The URL:
  • >>> f = CategoryForm({'name': 'Entertainment', 'slug': 'entertainment', 'url': 'entertainment'}) >>> f.is_valid() True >>> f.cleaned_data {'url': u'entertainment', 'name': u'Entertainment', 'slug': u'entertainment'} >>> obj = f.save() >>> obj >>> Category.objects.all() [] >>> f = CategoryForm({'name': "It's a test", 'slug': 'its-test', 'url': 'test'}) >>> f.is_valid() True >>> f.cleaned_data {'url': u'test', 'name': u"It's a test", 'slug': u'its-test'} >>> obj = f.save() >>> obj >>> Category.objects.order_by('name') [, ] 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. >>> f = CategoryForm({'name': 'Third test', 'slug': 'third-test', 'url': 'third'}) >>> f.is_valid() True >>> f.cleaned_data {'url': u'third', 'name': u'Third test', 'slug': u'third-test'} >>> obj = f.save(commit=False) >>> obj >>> Category.objects.order_by('name') [, ] >>> obj.save() >>> Category.objects.order_by('name') [, , ] If you call save() with invalid data, you'll get a ValueError. >>> f = CategoryForm({'name': '', 'slug': '', 'url': 'foo'}) >>> f.errors {'name': [u'This field is required.'], 'slug': [u'This field is required.']} >>> f.cleaned_data Traceback (most recent call last): ... AttributeError: 'CategoryForm' object has no attribute 'cleaned_data' >>> f.save() Traceback (most recent call last): ... ValueError: The Category could not be created because the data didn't validate. >>> f = CategoryForm({'name': '', 'slug': '', 'url': 'foo'}) >>> f.save() Traceback (most recent call last): ... ValueError: The Category could not be created because the data didn't validate. Create a couple of Writers. >>> w = Writer(name='Mike Royko') >>> w.save() >>> w = Writer(name='Bob Woodward') >>> w.save() ManyToManyFields are represented by a MultipleChoiceField, ForeignKeys and any fields with the 'choices' attribute are represented by a ChoiceField. >>> class ArticleForm(ModelForm): ... class Meta: ... model = Article >>> f = ArticleForm(auto_id=False) >>> print f Headline: Slug: Pub date: Writer: Article: Status: Categories:
    Hold down "Control", or "Command" on a Mac, to select more than one. You can restrict a form to a subset of the complete list of fields by providing a 'fields' argument. If you try to save a model created with such a form, you need to ensure that the fields that are _not_ on the form have default values, or are allowed to have a value of None. If a field isn't specified on a form, the object created from the form can't provide a value for that field! >>> class PartialArticleForm(ModelForm): ... class Meta: ... model = Article ... fields = ('headline','pub_date') >>> f = PartialArticleForm(auto_id=False) >>> print f Headline: Pub date: Use form_for_instance to create a Form from a model instance. The difference between this Form and one created via form_for_model is that the object's current values are inserted as 'initial' data in each Field. >>> w = Writer.objects.get(name='Mike Royko') >>> class RoykoForm(ModelForm): ... class Meta: ... model = Writer >>> f = RoykoForm(auto_id=False, instance=w) >>> print f Name:
    Use both first and last names. >>> art = Article(headline='Test article', slug='test-article', pub_date=datetime.date(1988, 1, 4), writer=w, article='Hello.') >>> art.save() >>> art.id 1 >>> class TestArticleForm(ModelForm): ... class Meta: ... model = Article >>> f = TestArticleForm(auto_id=False, instance=art) >>> print f.as_ul()
  • Headline:
  • Slug:
  • Pub date:
  • Writer:
  • Article:
  • Status:
  • Categories: Hold down "Control", or "Command" on a Mac, to select more than one.
  • >>> f = TestArticleForm({'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() >>> test_art.id 1 >>> test_art = Article.objects.get(id=1) >>> test_art.headline u'Test headline' You can create a form over a subset of the available fields by specifying a 'fields' argument to form_for_instance. >>> class PartialArticleForm(ModelForm): ... class Meta: ... model = Article ... fields=('headline', 'slug', 'pub_date') >>> f = PartialArticleForm({'headline': u'New headline', 'slug': 'new-headline', 'pub_date': u'1988-01-04'}, auto_id=False, instance=art) >>> print f.as_ul()
  • Headline:
  • Slug:
  • Pub date:
  • >>> f.is_valid() True >>> new_art = f.save() >>> new_art.id 1 >>> new_art = Article.objects.get(id=1) >>> new_art.headline u'New headline' Add some categories and test the many-to-many form output. >>> new_art.categories.all() [] >>> new_art.categories.add(Category.objects.get(name='Entertainment')) >>> new_art.categories.all() [] >>> class TestArticleForm(ModelForm): ... class Meta: ... model = Article >>> f = TestArticleForm(auto_id=False, instance=new_art) >>> print f.as_ul()
  • Headline:
  • Slug:
  • Pub date:
  • Writer:
  • Article:
  • Status:
  • Categories: Hold down "Control", or "Command" on a Mac, to select more than one.
  • >>> f = TestArticleForm({'headline': u'New headline', 'slug': u'new-headline', 'pub_date': u'1988-01-04', ... 'writer': u'1', 'article': u'Hello.', 'categories': [u'1', u'2']}, instance=new_art) >>> new_art = f.save() >>> new_art.id 1 >>> new_art = Article.objects.get(id=1) >>> new_art.categories.order_by('name') [, ] Now, submit form data with no categories. This deletes the existing categories. >>> f = TestArticleForm({'headline': u'New headline', 'slug': u'new-headline', 'pub_date': u'1988-01-04', ... 'writer': u'1', 'article': u'Hello.'}, instance=new_art) >>> new_art = f.save() >>> new_art.id 1 >>> new_art = Article.objects.get(id=1) >>> new_art.categories.all() [] Create a new article, with categories, via the form. >>> class ArticleForm(ModelForm): ... class Meta: ... model = Article >>> f = ArticleForm({'headline': u'The walrus was Paul', 'slug': u'walrus-was-paul', 'pub_date': u'1967-11-01', ... 'writer': u'1', 'article': u'Test.', 'categories': [u'1', u'2']}) >>> new_art = f.save() >>> new_art.id 2 >>> new_art = Article.objects.get(id=2) >>> new_art.categories.order_by('name') [, ] Create a new article, with no categories, via the form. >>> class ArticleForm(ModelForm): ... class Meta: ... model = Article >>> f = ArticleForm({'headline': u'The walrus was Paul', 'slug': u'walrus-was-paul', 'pub_date': u'1967-11-01', ... 'writer': u'1', 'article': u'Test.'}) >>> new_art = f.save() >>> new_art.id 3 >>> new_art = Article.objects.get(id=3) >>> new_art.categories.all() [] Create a new article, with categories, via the form, but use commit=False. The m2m data won't be saved until save_m2m() is invoked on the form. >>> class ArticleForm(ModelForm): ... class Meta: ... model = Article >>> f = ArticleForm({'headline': u'The walrus was Paul', 'slug': 'walrus-was-paul', 'pub_date': u'1967-11-01', ... 'writer': u'1', 'article': u'Test.', 'categories': [u'1', u'2']}) >>> new_art = f.save(commit=False) # Manually save the instance >>> new_art.save() >>> new_art.id 4 # The instance doesn't have m2m data yet >>> new_art = Article.objects.get(id=4) >>> new_art.categories.all() [] # Save the m2m data on the form >>> f.save_m2m() >>> new_art.categories.order_by('name') [, ] Here, we define a custom ModelForm. Because it happens to have the same fields as the Category model, we can just call the form's save() to apply its changes to an existing Category instance. >>> class ShortCategory(ModelForm): ... name = CharField(max_length=5) ... slug = CharField(max_length=5) ... url = CharField(max_length=3) >>> cat = Category.objects.get(name='Third test') >>> cat >>> cat.id 3 >>> form = ShortCategory({'name': 'Third', 'slug': 'third', 'url': '3rd'}, instance=cat) >>> form.save() >>> Category.objects.get(id=3) Here, we demonstrate that choices for a ForeignKey ChoiceField are determined at runtime, based on the data in the database when the form is displayed, not the data in the database when the form is instantiated. >>> class ArticleForm(ModelForm): ... class Meta: ... model = Article >>> f = ArticleForm(auto_id=False) >>> print f.as_ul()
  • Headline:
  • Slug:
  • Pub date:
  • Writer:
  • Article:
  • Status:
  • Categories: Hold down "Control", or "Command" on a Mac, to select more than one.
  • >>> Category.objects.create(name='Fourth', url='4th') >>> Writer.objects.create(name='Carl Bernstein') >>> print f.as_ul()
  • Headline:
  • Slug:
  • Pub date:
  • Writer:
  • Article:
  • Status:
  • Categories: Hold down "Control", or "Command" on a Mac, to select more than one.
  • # ModelChoiceField ############################################################ >>> from django.newforms import ModelChoiceField, ModelMultipleChoiceField >>> f = ModelChoiceField(Category.objects.all()) >>> list(f.choices) [(u'', u'---------'), (1, u'Entertainment'), (2, u"It's a test"), (3, u'Third'), (4, u'Fourth')] >>> f.clean('') Traceback (most recent call last): ... ValidationError: [u'This field is required.'] >>> f.clean(None) Traceback (most recent call last): ... ValidationError: [u'This field is required.'] >>> f.clean(0) Traceback (most recent call last): ... ValidationError: [u'Select a valid choice. That choice is not one of the available choices.'] >>> f.clean(3) >>> f.clean(2) # Add a Category object *after* the ModelChoiceField has already been # instantiated. This proves clean() checks the database during clean() rather # than caching it at time of instantiation. >>> Category.objects.create(name='Fifth', url='5th') >>> f.clean(5) # Delete a Category object *after* the ModelChoiceField has already been # instantiated. This proves clean() checks the database during clean() rather # than caching it at time of instantiation. >>> Category.objects.get(url='5th').delete() >>> f.clean(5) Traceback (most recent call last): ... ValidationError: [u'Select a valid choice. That choice is not one of the available choices.'] >>> f = ModelChoiceField(Category.objects.filter(pk=1), required=False) >>> print f.clean('') None >>> f.clean('') >>> f.clean('1') >>> f.clean('100') Traceback (most recent call last): ... ValidationError: [u'Select a valid choice. That choice is not one of the available choices.'] # queryset can be changed after the field is created. >>> f.queryset = Category.objects.exclude(name='Fourth') >>> list(f.choices) [(u'', u'---------'), (1, u'Entertainment'), (2, u"It's a test"), (3, u'Third')] >>> f.clean(3) >>> f.clean(4) Traceback (most recent call last): ... ValidationError: [u'Select a valid choice. That choice is not one of the available choices.'] # ModelMultipleChoiceField #################################################### >>> f = ModelMultipleChoiceField(Category.objects.all()) >>> list(f.choices) [(1, u'Entertainment'), (2, u"It's a test"), (3, u'Third'), (4, u'Fourth')] >>> f.clean(None) Traceback (most recent call last): ... ValidationError: [u'This field is required.'] >>> f.clean([]) Traceback (most recent call last): ... ValidationError: [u'This field is required.'] >>> f.clean([1]) [] >>> f.clean([2]) [] >>> f.clean(['1']) [] >>> f.clean(['1', '2']) [, ] >>> f.clean([1, '2']) [, ] >>> f.clean((1, '2')) [, ] >>> f.clean(['100']) Traceback (most recent call last): ... ValidationError: [u'Select a valid choice. 100 is not one of the available choices.'] >>> f.clean('hello') Traceback (most recent call last): ... ValidationError: [u'Enter a list of values.'] # Add a Category object *after* the ModelMultipleChoiceField has already been # instantiated. This proves clean() checks the database during clean() rather # than caching it at time of instantiation. >>> Category.objects.create(id=6, name='Sixth', url='6th') >>> f.clean([6]) [] # Delete a Category object *after* the ModelMultipleChoiceField has already been # instantiated. This proves clean() checks the database during clean() rather # than caching it at time of instantiation. >>> Category.objects.get(url='6th').delete() >>> f.clean([6]) Traceback (most recent call last): ... ValidationError: [u'Select a valid choice. 6 is not one of the available choices.'] >>> f = ModelMultipleChoiceField(Category.objects.all(), required=False) >>> f.clean([]) [] >>> f.clean(()) [] >>> f.clean(['10']) Traceback (most recent call last): ... ValidationError: [u'Select a valid choice. 10 is not one of the available choices.'] >>> f.clean(['3', '10']) Traceback (most recent call last): ... ValidationError: [u'Select a valid choice. 10 is not one of the available choices.'] >>> f.clean(['1', '10']) Traceback (most recent call last): ... ValidationError: [u'Select a valid choice. 10 is not one of the available choices.'] # queryset can be changed after the field is created. >>> f.queryset = Category.objects.exclude(name='Fourth') >>> list(f.choices) [(1, u'Entertainment'), (2, u"It's a test"), (3, u'Third')] >>> f.clean([3]) [] >>> f.clean([4]) Traceback (most recent call last): ... ValidationError: [u'Select a valid choice. 4 is not one of the available choices.'] >>> f.clean(['3', '4']) Traceback (most recent call last): ... ValidationError: [u'Select a valid choice. 4 is not one of the available choices.'] # PhoneNumberField ############################################################ >>> class PhoneNumberForm(ModelForm): ... class Meta: ... model = PhoneNumber >>> f = PhoneNumberForm({'phone': '(312) 555-1212', 'description': 'Assistance'}) >>> f.is_valid() True >>> f.cleaned_data {'phone': u'312-555-1212', 'description': u'Assistance'} """}