Fixed #12097 -- Cleaned up the documentation for ModelChoiceField and MultipleModelChoiceField. Thanks to JasonYosinski for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12712 bcc190cf-cafb-0310-a4f2-bffc1f526a37
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Russell Keith-Magee 2010-03-08 03:20:55 +00:00
parent 6e030e7d1e
commit d1e37f2b39
1 changed files with 35 additions and 24 deletions

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@ -777,15 +777,22 @@ for ``TimeField`` are used.
Fields which handle relationships
---------------------------------
For representing relationships between models, two fields are
provided which can derive their choices from a ``QuerySet``:
Two fields are available for representing relationships between
models: :class:`ModelChoiceField` and
:class:`ModelMultipleChoiceField`. Both of these fields require a
single ``queryset`` parameter that is used to create the choices for
the field. Upon form validation, these fields will place either one
model object (in the case of ``ModelChoiceField``) or multiple model
objects (in the case of ``ModelMultipleChoiceField``) into the
``cleaned_data`` dictionary of the form.
``ModelChoiceField``
~~~~~~~~~~~~~~~~~~~~
.. class:: ModelChoiceField(**kwargs)
.. class:: ModelMultipleChoiceField(**kwargs)
These fields place one or more model objects into the ``cleaned_data``
dictionary of forms in which they're used. Both of these fields have an
additional required argument:
Allows the selection of a single model object, suitable for
representing a foreign key. A single argument is required:
.. attribute:: ModelChoiceField.queryset
@ -793,22 +800,7 @@ additional required argument:
field will be derived, and which will be used to validate the
user's selection.
``ModelChoiceField``
~~~~~~~~~~~~~~~~~~~~
Allows the selection of a single model object, suitable for
representing a foreign key.
The ``__unicode__`` method of the model will be called to generate
string representations of the objects for use in the field's choices;
to provide customized representations, subclass ``ModelChoiceField``
and override ``label_from_instance``. This method will receive a model
object, and should return a string suitable for representing it. For
example::
class MyModelChoiceField(ModelChoiceField):
def label_from_instance(self, obj):
return "My Object #%i" % obj.id
``ModelChoiceField`` also takes one optional argument:
.. attribute:: ModelChoiceField.empty_label
@ -828,13 +820,32 @@ example::
initial value, no empty choice is created (regardless of the value
of ``empty_label``).
The ``__unicode__`` method of the model will be called to generate
string representations of the objects for use in the field's choices;
to provide customized representations, subclass ``ModelChoiceField``
and override ``label_from_instance``. This method will receive a model
object, and should return a string suitable for representing it. For
example::
class MyModelChoiceField(ModelChoiceField):
def label_from_instance(self, obj):
return "My Object #%i" % obj.id
``ModelMultipleChoiceField``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. class:: ModelMultipleChoiceField(**kwargs)
Allows the selection of one or more model objects, suitable for
representing a many-to-many relation. As with ``ModelChoiceField``,
representing a many-to-many relation. As with :class:`ModelChoiceField`,
you can use ``label_from_instance`` to customize the object
representations.
representations, and ``queryset`` is a required parameter:
.. attribute:: ModelMultipleChoiceField.queryset
A ``QuerySet`` of model objects from which the choices for the
field will be derived, and which will be used to validate the
user's selection.
Creating custom fields
----------------------