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Fixed #7830 -- Removed all of the remaining, deprecated, non-oldforms features:
* Support for representing files as strings was removed. Use `django.core.files.base.ContentFile` instead. * Support for representing uploaded files as dictionaries was removed. Use `django.core.files.uploadedfile.SimpleUploadedFile` instead. * The `filename`, `file_name`, `file_size`, and `chuck` properties of `UploadedFile` were removed. Use the `name`, `name`, `size`, and `chunks` properties instead, respectively. * The `get_FIELD_filename`, `get_FIELD_url`, `get_FIELD_size`, and `save_FIELD_file` methods for Models with `FileField` fields were removed. Instead, use the `path`, `url`, and `size` attributes and `save` method on the field itself, respectively. * The `get_FIELD_width` and `get_FIELD_height` methods for Models with `ImageField` fields were removed. Use the `width` and `height` attributes on the field itself instead. * The dispatcher `connect`, `disconnect`, `send`, and `sendExact` functions were removed. Use the signal object's own `connect`, `disconnect`, `send`, and `send` methods instead, respectively. * The `form_for_model` and `form_for_instance` functions were removed. Use a `ModelForm` subclass instead. * Support for importing `django.newforms` was removed. Use `django.forms` instead. * Support for importing `django.utils.images` was removed. Use `django.core.files.images` instead. * Support for the `follow` argument in the `create_object` and `update_object` generic views was removed. Use the `django.forms` package and the new `form_class` argument instead. git-svn-id: http://code.djangoproject.com/svn/django/trunk@8291 bcc190cf-cafb-0310-a4f2-bffc1f526a37
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@ -483,8 +483,7 @@ accepted lookup types to ``exact`` and ``in``::
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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Returns the default form field to use when this field is displayed
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in a model. This method is called by the `helper functions`_
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``form_for_model()`` and ``form_for_instance()``.
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in a model.
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All of the ``kwargs`` dictionary is passed directly to the form field's
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``__init__()`` method. Normally, all you need to do is set up a good default
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@ -1418,7 +1418,7 @@ SQL equivalent::
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You can also use a queryset to dynamically evaluate the list of values
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instead of providing a list of literal values. The queryset must be
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reduced to a list of individual values using the ``values()`` method,
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reduced to a list of individual values using the ``values()`` method,
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and then converted into a query using the ``query`` attribute::
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Entry.objects.filter(blog__in=Blog.objects.filter(name__contains='Cheddar').values('pk').query)
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@ -2106,7 +2106,7 @@ One-to-one relationships
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------------------------
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One-to-one relationships are very similar to many-to-one relationships.
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If you define a OneToOneField on your model, instances of that model will have
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If you define a OneToOneField on your model, instances of that model will have
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access to the related object via a simple attribute of the model.
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For example::
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@ -2128,9 +2128,9 @@ represents a single object, rather than a collection of objects::
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If no object has been assigned to this relationship, Django will raise
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a ``DoesNotExist`` exception.
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Instances can be assigned to the reverse relationship in the same way as
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Instances can be assigned to the reverse relationship in the same way as
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you would assign the forward relationship::
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e.entrydetail = ed
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Many-to-many relationships
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@ -2313,37 +2313,6 @@ For a full example, see the `lookup API sample model`_.
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.. _lookup API sample model: ../models/lookup/
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get_FOO_filename()
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------------------
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**Deprecated in Django development version**; use ``object.FOO.name`` instead.
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See `managing files`_ for details.
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get_FOO_url()
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-------------
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**Deprecated in Django development version**; use ``object.FOO.url`` instead.
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See `managing files`_ for details.
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get_FOO_size()
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--------------
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**Deprecated in Django development version**; use ``object.FOO.size`` instead.
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See `managing files`_ for details.
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save_FOO_file(filename, raw_contents)
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-------------------------------------
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**Deprecated in Django development version**; use ``object.FOO.save()`` instead.
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See `managing files`_ for details.
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get_FOO_height() and get_FOO_width()
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------------------------------------
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**Deprecated in Django development version**; use ``object.FOO.width`` and
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``object.FOO.height`` instead. See `managing files`_ for details.
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.. _`managing files`: ../files/
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Shortcuts
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=========
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@ -1,425 +0,0 @@
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Generating forms for models
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===========================
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.. admonition:: Note
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The APIs described in this document have been deprecated. If you're
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developing new code, use `ModelForms`_ instead.
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.. _ModelForms: ../modelforms/
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If you're building a database-driven app, chances are you'll have forms that
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map closely to Django models. For instance, you might have a ``BlogComment``
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model, and you want to create a form that lets people submit comments. In this
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case, it would be redundant to define the field types in your form, because
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you've already defined the fields in your model.
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For this reason, Django provides a few helper functions that let you create a
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``Form`` class from a Django model.
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``form_for_model()``
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--------------------
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The method ``django.forms.form_for_model()`` creates a form based on the
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definition of a specific model. Pass it the model class, and it will return a
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``Form`` class that contains a form field for each model field.
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For example::
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>>> from django.forms import form_for_model
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# Create the form class.
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>>> ArticleForm = form_for_model(Article)
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# Create an empty form instance.
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>>> f = ArticleForm()
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It bears repeating that ``form_for_model()`` takes the model *class*, not a
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model instance, and it returns a ``Form`` *class*, not a ``Form`` instance.
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Field types
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~~~~~~~~~~~
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The generated ``Form`` class will have a form field for every model field. Each
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model field has a corresponding default form field. For example, a
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``CharField`` on a model is represented as a ``CharField`` on a form. A
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model ``ManyToManyField`` is represented as a ``MultipleChoiceField``. Here is
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the full list of conversions:
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=============================== ========================================
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Model field Form field
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=============================== ========================================
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``AutoField`` Not represented in the form
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``BooleanField`` ``BooleanField``
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``CharField`` ``CharField`` with ``max_length`` set to
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the model field's ``max_length``
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``CommaSeparatedIntegerField`` ``CharField``
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``DateField`` ``DateField``
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``DateTimeField`` ``DateTimeField``
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``DecimalField`` ``DecimalField``
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``EmailField`` ``EmailField``
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``FileField`` ``FileField``
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``FilePathField`` ``CharField``
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``FloatField`` ``FloatField``
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``ForeignKey`` ``ModelChoiceField`` (see below)
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``ImageField`` ``ImageField``
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``IntegerField`` ``IntegerField``
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``IPAddressField`` ``IPAddressField``
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``ManyToManyField`` ``ModelMultipleChoiceField`` (see
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below)
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``NullBooleanField`` ``CharField``
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``PhoneNumberField`` ``USPhoneNumberField``
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(from ``django.contrib.localflavor.us``)
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``PositiveIntegerField`` ``IntegerField``
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``PositiveSmallIntegerField`` ``IntegerField``
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``SlugField`` ``CharField``
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``SmallIntegerField`` ``IntegerField``
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``TextField`` ``CharField`` with ``widget=Textarea``
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``TimeField`` ``TimeField``
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``URLField`` ``URLField`` with ``verify_exists`` set
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to the model field's ``verify_exists``
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``USStateField`` ``CharField`` with
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``widget=USStateSelect``
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(``USStateSelect`` is from
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``django.contrib.localflavor.us``)
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``XMLField`` ``CharField`` with ``widget=Textarea``
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=============================== ========================================
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.. note::
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The ``FloatField`` form field and ``DecimalField`` model and form fields
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are new in the development version.
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As you might expect, the ``ForeignKey`` and ``ManyToManyField`` model field
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types are special cases:
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* ``ForeignKey`` is represented by ``django.forms.ModelChoiceField``,
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which is a ``ChoiceField`` whose choices are a model ``QuerySet``.
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* ``ManyToManyField`` is represented by
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``django.forms.ModelMultipleChoiceField``, which is a
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``MultipleChoiceField`` whose choices are a model ``QuerySet``.
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In addition, each generated form field has attributes set as follows:
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* If the model field has ``blank=True``, then ``required`` is set to
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``False`` on the form field. Otherwise, ``required=True``.
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* The form field's ``label`` is set to the ``verbose_name`` of the model
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field, with the first character capitalized.
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* The form field's ``help_text`` is set to the ``help_text`` of the model
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field.
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* If the model field has ``choices`` set, then the form field's ``widget``
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will be set to ``Select``, with choices coming from the model field's
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``choices``. The choices will normally include the blank choice which is
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selected by default. If the field is required, this forces the user to
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make a selection. The blank choice will not be included if the model
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field has ``blank=False`` and an explicit ``default`` value (the
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``default`` value will be initially selected instead).
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Finally, note that you can override the form field used for a given model
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field. See "Overriding the default field types" below.
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A full example
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~~~~~~~~~~~~~~
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Consider this set of models::
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from django.db import models
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TITLE_CHOICES = (
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('MR', 'Mr.'),
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('MRS', 'Mrs.'),
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('MS', 'Ms.'),
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)
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class Author(models.Model):
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name = models.CharField(max_length=100)
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title = models.CharField(max_length=3, choices=TITLE_CHOICES)
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birth_date = models.DateField(blank=True, null=True)
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def __unicode__(self):
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return self.name
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class Book(models.Model):
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name = models.CharField(max_length=100)
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authors = models.ManyToManyField(Author)
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With these models, a call to ``form_for_model(Author)`` would return a ``Form``
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class equivalent to this::
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class AuthorForm(forms.Form):
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name = forms.CharField(max_length=100)
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title = forms.CharField(max_length=3,
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widget=forms.Select(choices=TITLE_CHOICES))
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birth_date = forms.DateField(required=False)
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A call to ``form_for_model(Book)`` would return a ``Form`` class equivalent to
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this::
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class BookForm(forms.Form):
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name = forms.CharField(max_length=100)
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authors = forms.ModelMultipleChoiceField(queryset=Author.objects.all())
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The ``save()`` method
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~~~~~~~~~~~~~~~~~~~~~
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Every form produced by ``form_for_model()`` also has a ``save()`` method. This
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method creates and saves a database object from the data bound to the form. For
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example::
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# Create a form instance from POST data.
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>>> f = ArticleForm(request.POST)
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# Save a new Article object from the form's data.
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>>> new_article = f.save()
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Note that ``save()`` will raise a ``ValueError`` if the data in the form
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doesn't validate -- i.e., ``if form.errors``.
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This ``save()`` method accepts an optional ``commit`` keyword argument, which
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accepts either ``True`` or ``False``. If you call ``save()`` with
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``commit=False``, then it will return an object that hasn't yet been saved to
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the database. In this case, it's up to you to call ``save()`` on the resulting
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model instance. This is useful if you want to do custom processing on the
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object before saving it. ``commit`` is ``True`` by default.
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Another side effect of using ``commit=False`` is seen when your model has
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a many-to-many relation with another model. If your model has a many-to-many
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relation and you specify ``commit=False`` when you save a form, Django cannot
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immediately save the form data for the many-to-many relation. This is because
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it isn't possible to save many-to-many data for an instance until the instance
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exists in the database.
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To work around this problem, every time you save a form using ``commit=False``,
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Django adds a ``save_m2m()`` method to the form created by ``form_for_model``.
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After you've manually saved the instance produced by the form, you can invoke
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``save_m2m()`` to save the many-to-many form data. For example::
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# Create a form instance with POST data.
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>>> f = AuthorForm(request.POST)
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# Create, but don't save the new author instance.
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>>> new_author = f.save(commit=False)
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# Modify the author in some way.
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>>> new_author.some_field = 'some_value'
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# Save the new instance.
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>>> new_author.save()
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# Now, save the many-to-many data for the form.
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>>> f.save_m2m()
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Calling ``save_m2m()`` is only required if you use ``save(commit=False)``.
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When you use a simple ``save()`` on a form, all data -- including
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many-to-many data -- is saved without the need for any additional method calls.
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For example::
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# Create a form instance with POST data.
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>>> f = AuthorForm(request.POST)
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# Create and save the new author instance. There's no need to do anything else.
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>>> new_author = f.save()
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Using an alternate base class
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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If you want to add custom methods to the form generated by
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``form_for_model()``, write a class that extends ``django.forms.BaseForm``
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and contains your custom methods. Then, use the ``form`` argument to
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``form_for_model()`` to tell it to use your custom form as its base class.
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For example::
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# Create the new base class.
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>>> class MyBase(BaseForm):
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... def my_method(self):
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... # Do whatever the method does
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# Create the form class with a different base class.
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>>> ArticleForm = form_for_model(Article, form=MyBase)
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# Instantiate the form.
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>>> f = ArticleForm()
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# Use the base class method.
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>>> f.my_method()
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Using a subset of fields on the form
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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**New in Django development version**
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In some cases, you may not want all the model fields to appear on the generated
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form. There are two ways of telling ``form_for_model()`` to use only a subset
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of the model fields:
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1. Set ``editable=False`` on the model field. As a result, *any* form
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created from the model via ``form_for_model()`` will not include that
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field.
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2. Use the ``fields`` argument to ``form_for_model()``. This argument, if
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given, should be a list of field names to include in the form.
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For example, if you want a form for the ``Author`` model (defined above)
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that includes only the ``name`` and ``title`` fields, you would specify
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``fields`` like this::
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PartialArticleForm = form_for_model(Author, fields=('name', 'title'))
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.. note::
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If you specify ``fields`` when creating a form with ``form_for_model()``,
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then the fields that are *not* specified will not be set by the form's
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``save()`` method. Django will prevent any attempt to save an incomplete
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model, so if the model does not allow the missing fields to be empty, and
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does not provide a default value for the missing fields, any attempt to
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``save()`` a ``form_for_model`` with missing fields will fail. To avoid
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this failure, you must use ``save(commit=False)`` and manually set any
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extra required fields::
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instance = form.save(commit=False)
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instance.required_field = 'new value'
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instance.save()
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See the `section on saving forms`_ for more details on using
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``save(commit=False)``.
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.. _section on saving forms: `The save() method`_
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Overriding the default field types
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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The default field types, as described in the "Field types" table above, are
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sensible defaults; if you have a ``DateField`` in your model, chances are you'd
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want that to be represented as a ``DateField`` in your form. But
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``form_for_model()`` gives you the flexibility of changing the form field type
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for a given model field. You do this by specifying a **formfield callback**.
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A formfield callback is a function that, when provided with a model field,
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returns a form field instance. When constructing a form, ``form_for_model()``
|
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asks the formfield callback to provide form field types.
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|
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By default, ``form_for_model()`` calls the ``formfield()`` method on the model
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field::
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def default_callback(field, **kwargs):
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return field.formfield(**kwargs)
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The ``kwargs`` are any keyword arguments that might be passed to the form
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field, such as ``required=True`` or ``label='Foo'``.
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For example, if you wanted to use ``MyDateFormField`` for any ``DateField``
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field on the model, you could define the callback::
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>>> def my_callback(field, **kwargs):
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... if isinstance(field, models.DateField):
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... return MyDateFormField(**kwargs)
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... else:
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... return field.formfield(**kwargs)
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>>> ArticleForm = form_for_model(Article, formfield_callback=my_callback)
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Note that your callback needs to handle *all* possible model field types, not
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just the ones that you want to behave differently to the default. That's why
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this example has an ``else`` clause that implements the default behavior.
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.. warning::
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The field that is passed into the ``formfield_callback`` function in
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``form_for_model()`` and ``form_for_instance`` is the field instance from
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your model's class. You **must not** alter that object at all; treat it
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as read-only!
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|
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If you make any alterations to that object, it will affect any future
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users of the model class, because you will have changed the field object
|
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used to construct the class. This is almost certainly what you don't want
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to have happen.
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Finding the model associated with a form
|
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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|
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The model class that was used to construct the form is available
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using the ``_model`` property of the generated form::
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|
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>>> ArticleForm = form_for_model(Article)
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>>> ArticleForm._model
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<class 'myapp.models.Article'>
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|
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``form_for_instance()``
|
||||
-----------------------
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|
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``form_for_instance()`` is like ``form_for_model()``, but it takes a model
|
||||
instance instead of a model class::
|
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|
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# Create an Author.
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>>> a = Author(name='Joe Smith', title='MR', birth_date=None)
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>>> a.save()
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|
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# Create a form for this particular Author.
|
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>>> AuthorForm = form_for_instance(a)
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|
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# Instantiate the form.
|
||||
>>> f = AuthorForm()
|
||||
|
||||
When a form created by ``form_for_instance()`` is created, the initial data
|
||||
values for the form fields are drawn from the instance. However, this data is
|
||||
not bound to the form. You will need to bind data to the form before the form
|
||||
can be saved.
|
||||
|
||||
Unlike ``form_for_model()``, a choice field in form created by
|
||||
``form_for_instance()`` will not include the blank choice if the respective
|
||||
model field has ``blank=False``. The initial choice is drawn from the instance.
|
||||
|
||||
When you call ``save()`` on a form created by ``form_for_instance()``,
|
||||
the database instance will be updated. As in ``form_for_model()``, ``save()``
|
||||
will raise ``ValueError`` if the data doesn't validate.
|
||||
|
||||
``form_for_instance()`` has ``form``, ``fields`` and ``formfield_callback``
|
||||
arguments that behave the same way as they do for ``form_for_model()``.
|
||||
|
||||
Let's modify the earlier `contact form`_ view example a little bit. Suppose we
|
||||
have a ``Message`` model that holds each contact submission. Something like::
|
||||
|
||||
class Message(models.Model):
|
||||
subject = models.CharField(max_length=100)
|
||||
message = models.TextField()
|
||||
sender = models.EmailField()
|
||||
cc_myself = models.BooleanField(required=False)
|
||||
|
||||
You could use this model to create a form (using ``form_for_model()``). You
|
||||
could also use existing ``Message`` instances to create a form for editing
|
||||
messages. The `simple example view`_ can be changed slightly to accept the ``id`` value
|
||||
of an existing ``Message`` and present it for editing::
|
||||
|
||||
def contact_edit(request, msg_id):
|
||||
# Create the form from the message id.
|
||||
message = get_object_or_404(Message, id=msg_id)
|
||||
ContactForm = form_for_instance(message)
|
||||
|
||||
if request.method == 'POST':
|
||||
form = ContactForm(request.POST)
|
||||
if form.is_valid():
|
||||
form.save()
|
||||
return HttpResponseRedirect('/url/on_success/')
|
||||
else:
|
||||
form = ContactForm()
|
||||
return render_to_response('contact.html', {'form': form})
|
||||
|
||||
Aside from how we create the ``ContactForm`` class here, the main point to
|
||||
note is that the form display in the ``GET`` branch of the function
|
||||
will use the values from the ``message`` instance as initial values for the
|
||||
form field.
|
||||
|
||||
.. _contact form: ../forms/#simple-view-example
|
||||
.. _`simple example view`: ../forms/#simple-view-example
|
||||
|
||||
When should you use ``form_for_model()`` and ``form_for_instance()``?
|
||||
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
|
||||
The ``form_for_model()`` and ``form_for_instance()`` functions are meant to be
|
||||
shortcuts for the common case. If you want to create a form whose fields map to
|
||||
more than one model, or a form that contains fields that *aren't* on a model,
|
||||
you shouldn't use these shortcuts. Creating a ``Form`` class the "long" way
|
||||
isn't that difficult, after all.
|
|
@ -1828,11 +1828,7 @@ Generating forms for models
|
|||
The prefered way of generating forms that work with models is explained in the
|
||||
`ModelForms documentation`_.
|
||||
|
||||
Looking for the ``form_for_model`` and ``form_for_instance`` documentation?
|
||||
They've been deprecated, but you can still `view the documentation`_.
|
||||
|
||||
.. _ModelForms documentation: ../modelforms/
|
||||
.. _view the documentation: ../form_for_model/
|
||||
|
||||
Media
|
||||
=====
|
||||
|
|
|
@ -308,12 +308,11 @@ For example, say your ``MEDIA_ROOT`` is set to ``'/home/media'``, and
|
|||
upload a file on Jan. 15, 2007, it will be saved in the directory
|
||||
``/home/media/photos/2007/01/15``.
|
||||
|
||||
If you want to retrieve the upload file's on-disk filename, or a URL that
|
||||
refers to that file, or the file's size, you can use the
|
||||
``get_FOO_filename()``, ``get_FOO_url()`` and ``get_FOO_size()`` methods.
|
||||
They are all documented here__.
|
||||
Information about the uploaded ``File`` object, such as its on-disk filename,
|
||||
its size, or its URL, is available via attributes on the object itself. See the
|
||||
`managing files`__ documentation for more information about ``File`` objects.
|
||||
|
||||
__ ../db-api/#get-foo-filename
|
||||
__ ../files/
|
||||
|
||||
Note that whenever you deal with uploaded files, you should pay close attention
|
||||
to where you're uploading them and what type of files they are, to avoid
|
||||
|
@ -392,19 +391,17 @@ image. Has two extra optional arguments, ``height_field`` and
|
|||
``width_field``, which, if set, will be auto-populated with the height and
|
||||
width of the image each time a model instance is saved.
|
||||
|
||||
In addition to the special ``get_FOO_*`` methods that are available for
|
||||
``FileField``, an ``ImageField`` also has ``get_FOO_height()`` and
|
||||
``get_FOO_width()`` methods. These are documented elsewhere_.
|
||||
In addition to the `standard attributes and methods`_ that are available for
|
||||
``FileField``, an ``ImageField`` also has ``width`` and ``height`` attributes.
|
||||
|
||||
Requires the `Python Imaging Library`_.
|
||||
|
||||
.. _Python Imaging Library: http://www.pythonware.com/products/pil/
|
||||
.. _elsewhere: ../db-api/#get-foo-height-and-get-foo-width
|
||||
|
||||
**New in development version:** By default, ``ImageField`` instances are
|
||||
created as ``varchar(100)`` columns in your database. As with other fields, you
|
||||
can change the maximum length using the ``max_length`` argument.
|
||||
|
||||
.. _standard attributes and methods: ../files/#file-attributes-and-methods
|
||||
.. _Python Imaging Library: http://www.pythonware.com/products/pil/
|
||||
|
||||
``IntegerField``
|
||||
~~~~~~~~~~~~~~~~
|
||||
|
@ -605,10 +602,10 @@ be used for organizational purposes::
|
|||
('unknown', 'Unknown'),
|
||||
)
|
||||
|
||||
The first element in each tuple is the name to apply to the group. The
|
||||
The first element in each tuple is the name to apply to the group. The
|
||||
second element is an iterable of 2-tuples, with each 2-tuple containing
|
||||
a value and a human-readable name for an option. Grouped options may be
|
||||
combined with ungrouped options within a single list (such as the
|
||||
a value and a human-readable name for an option. Grouped options may be
|
||||
combined with ungrouped options within a single list (such as the
|
||||
`unknown` option in this example).
|
||||
|
||||
For each model field that has ``choices`` set, Django will add a method to
|
||||
|
@ -981,12 +978,12 @@ the relationship should work. All are optional:
|
|||
Extra fields on many-to-many relationships
|
||||
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
|
||||
**New in Django development version**
|
||||
**New in Django development version**
|
||||
|
||||
When you're only dealing with simple many-to-many relationships such as
|
||||
mixing and matching pizzas and toppings, a standard ``ManyToManyField``
|
||||
is all you need. However, sometimes you may need to associate data with the
|
||||
relationship between two models.
|
||||
relationship between two models.
|
||||
|
||||
For example, consider the case of an application tracking the musical groups
|
||||
which musicians belong to. There is a many-to-many relationship between a person
|
||||
|
@ -1021,7 +1018,7 @@ something like this::
|
|||
date_joined = models.DateField()
|
||||
invite_reason = models.CharField(max_length=64)
|
||||
|
||||
When you set up the intermediary model, you explicitly specify foreign
|
||||
When you set up the intermediary model, you explicitly specify foreign
|
||||
keys to the models that are involved in the ManyToMany relation. This
|
||||
explicit declaration defines how the two models are related.
|
||||
|
||||
|
@ -1030,8 +1027,8 @@ There are a few restrictions on the intermediate model:
|
|||
* Your intermediate model must contain one - and *only* one - foreign key
|
||||
on the target model (this would be ``Person`` in our example). If you
|
||||
have more than one foreign key, a validation error will be raised.
|
||||
|
||||
* Your intermediate model must contain one - and *only* one - foreign key
|
||||
|
||||
* Your intermediate model must contain one - and *only* one - foreign key
|
||||
on the source model (this would be ``Group`` in our example). If you
|
||||
have more than one foreign key, a validation error will be raised.
|
||||
|
||||
|
@ -1040,22 +1037,22 @@ There are a few restrictions on the intermediate model:
|
|||
case, two foreign keys to the same model are permitted, but they
|
||||
will be treated as the two (different) sides of the many-to-many
|
||||
relation.
|
||||
|
||||
|
||||
* When defining a many-to-many relationship from a model to
|
||||
itself, using an intermediary model, you *must* use
|
||||
``symmetrical=False`` (see the documentation for
|
||||
``ManyToManyField`` above).
|
||||
|
||||
Now that you have set up your ``ManyToManyField`` to use your intermediary
|
||||
Now that you have set up your ``ManyToManyField`` to use your intermediary
|
||||
model (Membership, in this case), you're ready to start creating some
|
||||
many-to-many relationships. You do this by creating instances of the
|
||||
intermediate model::
|
||||
|
||||
|
||||
>>> ringo = Person.objects.create(name="Ringo Starr")
|
||||
>>> paul = Person.objects.create(name="Paul McCartney")
|
||||
>>> beatles = Group.objects.create(name="The Beatles")
|
||||
>>> m1 = Membership(person=ringo, group=beatles,
|
||||
... date_joined=date(1962, 8, 16),
|
||||
... date_joined=date(1962, 8, 16),
|
||||
... invite_reason= "Needed a new drummer.")
|
||||
>>> m1.save()
|
||||
>>> beatles.members.all()
|
||||
|
@ -1063,7 +1060,7 @@ intermediate model::
|
|||
>>> ringo.group_set.all()
|
||||
[<Group: The Beatles>]
|
||||
>>> m2 = Membership.objects.create(person=paul, group=beatles,
|
||||
... date_joined=date(1960, 8, 1),
|
||||
... date_joined=date(1960, 8, 1),
|
||||
... invite_reason= "Wanted to form a band.")
|
||||
>>> beatles.members.all()
|
||||
[<Person: Ringo Starr>, <Person: Paul McCartney>]
|
||||
|
@ -1077,7 +1074,7 @@ or assignment (i.e., ``beatles.members = [...]``) to create relationships::
|
|||
>>> beatles.members.create(name="George Harrison")
|
||||
# AND NEITHER WILL THIS
|
||||
>>> beatles.members = [john, paul, ringo, george]
|
||||
|
||||
|
||||
Why? You can't just create a relationship between a Person and a Group - you
|
||||
need to specify all the detail for the relationship required by the
|
||||
Membership table. The simple ``add``, ``create`` and assignment calls
|
||||
|
@ -1094,15 +1091,15 @@ for an instance::
|
|||
>>> beatles.members.clear()
|
||||
|
||||
Once you have established the many-to-many relationships by creating instances
|
||||
of your intermediate model, you can issue queries. Just as with normal
|
||||
many-to-many relationships, you can query using the attributes of the
|
||||
of your intermediate model, you can issue queries. Just as with normal
|
||||
many-to-many relationships, you can query using the attributes of the
|
||||
many-to-many-related model::
|
||||
|
||||
# Find all the groups with a member whose name starts with 'Paul'
|
||||
>>> Groups.objects.filter(person__name__startswith='Paul')
|
||||
[<Group: The Beatles>]
|
||||
|
||||
As you are using an intermediate table, you can also query on the attributes
|
||||
As you are using an intermediate table, you can also query on the attributes
|
||||
of the intermediate model::
|
||||
|
||||
# Find all the members of the Beatles that joined after 1 Jan 1961
|
||||
|
@ -1110,7 +1107,7 @@ of the intermediate model::
|
|||
... group__name='The Beatles',
|
||||
... membership__date_joined__gt=date(1961,1,1))
|
||||
[<Person: Ringo Starr]
|
||||
|
||||
|
||||
One-to-one relationships
|
||||
~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
|
||||
|
@ -1555,7 +1552,7 @@ attributes by giving it a ``use_for_related_fields`` property::
|
|||
|
||||
class MyManager(models.Manager)::
|
||||
use_for_related_fields = True
|
||||
|
||||
|
||||
...
|
||||
|
||||
Model methods
|
||||
|
|
Loading…
Add table
Add a link
Reference in a new issue