mirror of https://github.com/django/django.git
644 lines
27 KiB
Plaintext
644 lines
27 KiB
Plaintext
.. _formsets:
|
|
|
|
Formsets
|
|
========
|
|
|
|
.. module:: django.forms.formsets
|
|
:synopsis: An abstraction for working with multiple forms on the same page.
|
|
|
|
.. class:: BaseFormSet
|
|
|
|
A formset is a layer of abstraction to work with multiple forms on the same
|
|
page. It can be best compared to a data grid. Let's say you have the following
|
|
form::
|
|
|
|
>>> from django import forms
|
|
>>> class ArticleForm(forms.Form):
|
|
... title = forms.CharField()
|
|
... pub_date = forms.DateField()
|
|
|
|
You might want to allow the user to create several articles at once. To create
|
|
a formset out of an ``ArticleForm`` you would do::
|
|
|
|
>>> from django.forms.formsets import formset_factory
|
|
>>> ArticleFormSet = formset_factory(ArticleForm)
|
|
|
|
You now have created a formset named ``ArticleFormSet``. The formset gives you
|
|
the ability to iterate over the forms in the formset and display them as you
|
|
would with a regular form::
|
|
|
|
>>> formset = ArticleFormSet()
|
|
>>> for form in formset:
|
|
... print(form.as_table())
|
|
<tr><th><label for="id_form-0-title">Title:</label></th><td><input type="text" name="form-0-title" id="id_form-0-title" /></td></tr>
|
|
<tr><th><label for="id_form-0-pub_date">Pub date:</label></th><td><input type="text" name="form-0-pub_date" id="id_form-0-pub_date" /></td></tr>
|
|
|
|
As you can see it only displayed one empty form. The number of empty forms
|
|
that is displayed is controlled by the ``extra`` parameter. By default,
|
|
:func:`~django.forms.formsets.formset_factory` defines one extra form; the
|
|
following example will display two blank forms::
|
|
|
|
>>> ArticleFormSet = formset_factory(ArticleForm, extra=2)
|
|
|
|
Iterating over the ``formset`` will render the forms in the order they were
|
|
created. You can change this order by providing an alternate implementation for
|
|
the ``__iter__()`` method.
|
|
|
|
Formsets can also be indexed into, which returns the corresponding form. If you
|
|
override ``__iter__``, you will need to also override ``__getitem__`` to have
|
|
matching behavior.
|
|
|
|
.. _formsets-initial-data:
|
|
|
|
Using initial data with a formset
|
|
---------------------------------
|
|
|
|
Initial data is what drives the main usability of a formset. As shown above
|
|
you can define the number of extra forms. What this means is that you are
|
|
telling the formset how many additional forms to show in addition to the
|
|
number of forms it generates from the initial data. Let's take a look at an
|
|
example::
|
|
|
|
>>> import datetime
|
|
>>> from django.forms.formsets import formset_factory
|
|
>>> from myapp.forms import ArticleForm
|
|
>>> ArticleFormSet = formset_factory(ArticleForm, extra=2)
|
|
>>> formset = ArticleFormSet(initial=[
|
|
... {'title': 'Django is now open source',
|
|
... 'pub_date': datetime.date.today(),}
|
|
... ])
|
|
|
|
>>> for form in formset:
|
|
... print(form.as_table())
|
|
<tr><th><label for="id_form-0-title">Title:</label></th><td><input type="text" name="form-0-title" value="Django is now open source" id="id_form-0-title" /></td></tr>
|
|
<tr><th><label for="id_form-0-pub_date">Pub date:</label></th><td><input type="text" name="form-0-pub_date" value="2008-05-12" id="id_form-0-pub_date" /></td></tr>
|
|
<tr><th><label for="id_form-1-title">Title:</label></th><td><input type="text" name="form-1-title" id="id_form-1-title" /></td></tr>
|
|
<tr><th><label for="id_form-1-pub_date">Pub date:</label></th><td><input type="text" name="form-1-pub_date" id="id_form-1-pub_date" /></td></tr>
|
|
<tr><th><label for="id_form-2-title">Title:</label></th><td><input type="text" name="form-2-title" id="id_form-2-title" /></td></tr>
|
|
<tr><th><label for="id_form-2-pub_date">Pub date:</label></th><td><input type="text" name="form-2-pub_date" id="id_form-2-pub_date" /></td></tr>
|
|
|
|
There are now a total of three forms showing above. One for the initial data
|
|
that was passed in and two extra forms. Also note that we are passing in a
|
|
list of dictionaries as the initial data.
|
|
|
|
.. seealso::
|
|
|
|
:ref:`Creating formsets from models with model formsets <model-formsets>`.
|
|
|
|
.. _formsets-max-num:
|
|
|
|
Limiting the maximum number of forms
|
|
------------------------------------
|
|
|
|
The ``max_num`` parameter to :func:`~django.forms.formsets.formset_factory`
|
|
gives you the ability to limit the number of forms the formset will display::
|
|
|
|
>>> from django.forms.formsets import formset_factory
|
|
>>> from myapp.forms import ArticleForm
|
|
>>> ArticleFormSet = formset_factory(ArticleForm, extra=2, max_num=1)
|
|
>>> formset = ArticleFormSet()
|
|
>>> for form in formset:
|
|
... print(form.as_table())
|
|
<tr><th><label for="id_form-0-title">Title:</label></th><td><input type="text" name="form-0-title" id="id_form-0-title" /></td></tr>
|
|
<tr><th><label for="id_form-0-pub_date">Pub date:</label></th><td><input type="text" name="form-0-pub_date" id="id_form-0-pub_date" /></td></tr>
|
|
|
|
If the value of ``max_num`` is greater than the number of existing items in the
|
|
initial data, up to ``extra`` additional blank forms will be added to the
|
|
formset, so long as the total number of forms does not exceed ``max_num``. For
|
|
example, if ``extra=2`` and ``max_num=2`` and the formset is initialized with
|
|
one ``initial`` item, a form for the initial item and one blank form will be
|
|
displayed.
|
|
|
|
If the number of items in the initial data exceeds ``max_num``, all initial
|
|
data forms will be displayed regardless of the value of ``max_num`` and no
|
|
extra forms will be displayed. For example, if ``extra=3`` and ``max_num=1``
|
|
and the formset is initialized with two initial items, two forms with the
|
|
initial data will be displayed.
|
|
|
|
A ``max_num`` value of ``None`` (the default) puts a high limit on the number
|
|
of forms displayed (1000). In practice this is equivalent to no limit.
|
|
|
|
By default, ``max_num`` only affects how many forms are displayed and does not
|
|
affect validation. If ``validate_max=True`` is passed to the
|
|
:func:`~django.forms.formsets.formset_factory`, then ``max_num`` will affect
|
|
validation. See :ref:`validate_max`.
|
|
|
|
Formset validation
|
|
------------------
|
|
|
|
Validation with a formset is almost identical to a regular ``Form``. There is
|
|
an ``is_valid`` method on the formset to provide a convenient way to validate
|
|
all forms in the formset::
|
|
|
|
>>> from django.forms.formsets import formset_factory
|
|
>>> from myapp.forms import ArticleForm
|
|
>>> ArticleFormSet = formset_factory(ArticleForm)
|
|
>>> data = {
|
|
... 'form-TOTAL_FORMS': '1',
|
|
... 'form-INITIAL_FORMS': '0',
|
|
... 'form-MAX_NUM_FORMS': '',
|
|
... }
|
|
>>> formset = ArticleFormSet(data)
|
|
>>> formset.is_valid()
|
|
True
|
|
|
|
We passed in no data to the formset which is resulting in a valid form. The
|
|
formset is smart enough to ignore extra forms that were not changed. If we
|
|
provide an invalid article::
|
|
|
|
>>> data = {
|
|
... 'form-TOTAL_FORMS': '2',
|
|
... 'form-INITIAL_FORMS': '0',
|
|
... 'form-MAX_NUM_FORMS': '',
|
|
... 'form-0-title': 'Test',
|
|
... 'form-0-pub_date': '1904-06-16',
|
|
... 'form-1-title': 'Test',
|
|
... 'form-1-pub_date': '', # <-- this date is missing but required
|
|
... }
|
|
>>> formset = ArticleFormSet(data)
|
|
>>> formset.is_valid()
|
|
False
|
|
>>> formset.errors
|
|
[{}, {'pub_date': ['This field is required.']}]
|
|
|
|
As we can see, ``formset.errors`` is a list whose entries correspond to the
|
|
forms in the formset. Validation was performed for each of the two forms, and
|
|
the expected error message appears for the second item.
|
|
|
|
.. method:: BaseFormSet.total_error_count()
|
|
|
|
To check how many errors there are in the formset, we can use the
|
|
``total_error_count`` method::
|
|
|
|
>>> # Using the previous example
|
|
>>> formset.errors
|
|
[{}, {'pub_date': ['This field is required.']}]
|
|
>>> len(formset.errors)
|
|
2
|
|
>>> formset.total_error_count()
|
|
1
|
|
|
|
We can also check if form data differs from the initial data (i.e. the form was
|
|
sent without any data)::
|
|
|
|
>>> data = {
|
|
... 'form-TOTAL_FORMS': '1',
|
|
... 'form-INITIAL_FORMS': '0',
|
|
... 'form-MAX_NUM_FORMS': '',
|
|
... 'form-0-title': '',
|
|
... 'form-0-pub_date': '',
|
|
... }
|
|
>>> formset = ArticleFormSet(data)
|
|
>>> formset.has_changed()
|
|
False
|
|
|
|
.. _understanding-the-managementform:
|
|
|
|
Understanding the ManagementForm
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
You may have noticed the additional data (``form-TOTAL_FORMS``,
|
|
``form-INITIAL_FORMS`` and ``form-MAX_NUM_FORMS``) that was required
|
|
in the formset's data above. This data is required for the
|
|
``ManagementForm``. This form is used by the formset to manage the
|
|
collection of forms contained in the formset. If you don't provide
|
|
this management data, an exception will be raised::
|
|
|
|
>>> data = {
|
|
... 'form-0-title': 'Test',
|
|
... 'form-0-pub_date': '',
|
|
... }
|
|
>>> formset = ArticleFormSet(data)
|
|
Traceback (most recent call last):
|
|
...
|
|
django.forms.utils.ValidationError: ['ManagementForm data is missing or has been tampered with']
|
|
|
|
It is used to keep track of how many form instances are being displayed. If
|
|
you are adding new forms via JavaScript, you should increment the count fields
|
|
in this form as well. On the other hand, if you are using JavaScript to allow
|
|
deletion of existing objects, then you need to ensure the ones being removed
|
|
are properly marked for deletion by including ``form-#-DELETE`` in the ``POST``
|
|
data. It is expected that all forms are present in the ``POST`` data regardless.
|
|
|
|
The management form is available as an attribute of the formset
|
|
itself. When rendering a formset in a template, you can include all
|
|
the management data by rendering ``{{ my_formset.management_form }}``
|
|
(substituting the name of your formset as appropriate).
|
|
|
|
``total_form_count`` and ``initial_form_count``
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
``BaseFormSet`` has a couple of methods that are closely related to the
|
|
``ManagementForm``, ``total_form_count`` and ``initial_form_count``.
|
|
|
|
``total_form_count`` returns the total number of forms in this formset.
|
|
``initial_form_count`` returns the number of forms in the formset that were
|
|
pre-filled, and is also used to determine how many forms are required. You
|
|
will probably never need to override either of these methods, so please be
|
|
sure you understand what they do before doing so.
|
|
|
|
``empty_form``
|
|
~~~~~~~~~~~~~~
|
|
|
|
``BaseFormSet`` provides an additional attribute ``empty_form`` which returns
|
|
a form instance with a prefix of ``__prefix__`` for easier use in dynamic
|
|
forms with JavaScript.
|
|
|
|
Custom formset validation
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
A formset has a ``clean`` method similar to the one on a ``Form`` class. This
|
|
is where you define your own validation that works at the formset level::
|
|
|
|
>>> from django.forms.formsets import BaseFormSet
|
|
>>> from django.forms.formsets import formset_factory
|
|
>>> from myapp.forms import ArticleForm
|
|
|
|
>>> class BaseArticleFormSet(BaseFormSet):
|
|
... def clean(self):
|
|
... """Checks that no two articles have the same title."""
|
|
... if any(self.errors):
|
|
... # Don't bother validating the formset unless each form is valid on its own
|
|
... return
|
|
... titles = []
|
|
... for form in self.forms:
|
|
... title = form.cleaned_data['title']
|
|
... if title in titles:
|
|
... raise forms.ValidationError("Articles in a set must have distinct titles.")
|
|
... titles.append(title)
|
|
|
|
>>> ArticleFormSet = formset_factory(ArticleForm, formset=BaseArticleFormSet)
|
|
>>> data = {
|
|
... 'form-TOTAL_FORMS': '2',
|
|
... 'form-INITIAL_FORMS': '0',
|
|
... 'form-MAX_NUM_FORMS': '',
|
|
... 'form-0-title': 'Test',
|
|
... 'form-0-pub_date': '1904-06-16',
|
|
... 'form-1-title': 'Test',
|
|
... 'form-1-pub_date': '1912-06-23',
|
|
... }
|
|
>>> formset = ArticleFormSet(data)
|
|
>>> formset.is_valid()
|
|
False
|
|
>>> formset.errors
|
|
[{}, {}]
|
|
>>> formset.non_form_errors()
|
|
['Articles in a set must have distinct titles.']
|
|
|
|
The formset ``clean`` method is called after all the ``Form.clean`` methods
|
|
have been called. The errors will be found using the ``non_form_errors()``
|
|
method on the formset.
|
|
|
|
.. _validate_max:
|
|
|
|
Validating the number of forms in a formset
|
|
-------------------------------------------
|
|
|
|
Django provides a couple ways to validate the minimum or maximum number of
|
|
submitted forms. Applications which need more customizable validation of the
|
|
number of forms should use custom formset validation.
|
|
|
|
``validate_max``
|
|
~~~~~~~~~~~~~~~~
|
|
|
|
If ``validate_max=True`` is passed to
|
|
:func:`~django.forms.formsets.formset_factory`, validation will also check
|
|
that the number of forms in the data set, minus those marked for
|
|
deletion, is less than or equal to ``max_num``.
|
|
|
|
>>> from django.forms.formsets import formset_factory
|
|
>>> from myapp.forms import ArticleForm
|
|
>>> ArticleFormSet = formset_factory(ArticleForm, max_num=1, validate_max=True)
|
|
>>> data = {
|
|
... 'form-TOTAL_FORMS': '2',
|
|
... 'form-INITIAL_FORMS': '0',
|
|
... 'form-MIN_NUM_FORMS': '',
|
|
... 'form-MAX_NUM_FORMS': '',
|
|
... 'form-0-title': 'Test',
|
|
... 'form-0-pub_date': '1904-06-16',
|
|
... 'form-1-title': 'Test 2',
|
|
... 'form-1-pub_date': '1912-06-23',
|
|
... }
|
|
>>> formset = ArticleFormSet(data)
|
|
>>> formset.is_valid()
|
|
False
|
|
>>> formset.errors
|
|
[{}, {}]
|
|
>>> formset.non_form_errors()
|
|
['Please submit 1 or fewer forms.']
|
|
|
|
``validate_max=True`` validates against ``max_num`` strictly even if
|
|
``max_num`` was exceeded because the amount of initial data supplied was
|
|
excessive.
|
|
|
|
.. note::
|
|
|
|
Regardless of ``validate_max``, if the number of forms in a data set
|
|
exceeds ``max_num`` by more than 1000, then the form will fail to validate
|
|
as if ``validate_max`` were set, and additionally only the first 1000
|
|
forms above ``max_num`` will be validated. The remainder will be
|
|
truncated entirely. This is to protect against memory exhaustion attacks
|
|
using forged POST requests.
|
|
|
|
``validate_min``
|
|
~~~~~~~~~~~~~~~~
|
|
|
|
If ``validate_min=True`` is passed to
|
|
:func:`~django.forms.formsets.formset_factory`, validation will also check
|
|
that the number of forms in the data set, minus those marked for
|
|
deletion, is greater than or equal to ``min_num``.
|
|
|
|
>>> from django.forms.formsets import formset_factory
|
|
>>> from myapp.forms import ArticleForm
|
|
>>> ArticleFormSet = formset_factory(ArticleForm, min_num=3, validate_min=True)
|
|
>>> data = {
|
|
... 'form-TOTAL_FORMS': '2',
|
|
... 'form-INITIAL_FORMS': '0',
|
|
... 'form-MIN_NUM_FORMS': '',
|
|
... 'form-MAX_NUM_FORMS': '',
|
|
... 'form-0-title': 'Test',
|
|
... 'form-0-pub_date': '1904-06-16',
|
|
... 'form-1-title': 'Test 2',
|
|
... 'form-1-pub_date': '1912-06-23',
|
|
... }
|
|
>>> formset = ArticleFormSet(data)
|
|
>>> formset.is_valid()
|
|
False
|
|
>>> formset.errors
|
|
[{}, {}]
|
|
>>> formset.non_form_errors()
|
|
['Please submit 3 or more forms.']
|
|
|
|
Dealing with ordering and deletion of forms
|
|
-------------------------------------------
|
|
|
|
The :func:`~django.forms.formsets.formset_factory` provides two optional
|
|
parameters ``can_order`` and ``can_delete`` to help with ordering of forms in
|
|
formsets and deletion of forms from a formset.
|
|
|
|
``can_order``
|
|
~~~~~~~~~~~~~
|
|
|
|
.. attribute:: BaseFormSet.can_order
|
|
|
|
Default: ``False``
|
|
|
|
Lets you create a formset with the ability to order::
|
|
|
|
>>> from django.forms.formsets import formset_factory
|
|
>>> from myapp.forms import ArticleForm
|
|
>>> ArticleFormSet = formset_factory(ArticleForm, can_order=True)
|
|
>>> formset = ArticleFormSet(initial=[
|
|
... {'title': 'Article #1', 'pub_date': datetime.date(2008, 5, 10)},
|
|
... {'title': 'Article #2', 'pub_date': datetime.date(2008, 5, 11)},
|
|
... ])
|
|
>>> for form in formset:
|
|
... print(form.as_table())
|
|
<tr><th><label for="id_form-0-title">Title:</label></th><td><input type="text" name="form-0-title" value="Article #1" id="id_form-0-title" /></td></tr>
|
|
<tr><th><label for="id_form-0-pub_date">Pub date:</label></th><td><input type="text" name="form-0-pub_date" value="2008-05-10" id="id_form-0-pub_date" /></td></tr>
|
|
<tr><th><label for="id_form-0-ORDER">Order:</label></th><td><input type="number" name="form-0-ORDER" value="1" id="id_form-0-ORDER" /></td></tr>
|
|
<tr><th><label for="id_form-1-title">Title:</label></th><td><input type="text" name="form-1-title" value="Article #2" id="id_form-1-title" /></td></tr>
|
|
<tr><th><label for="id_form-1-pub_date">Pub date:</label></th><td><input type="text" name="form-1-pub_date" value="2008-05-11" id="id_form-1-pub_date" /></td></tr>
|
|
<tr><th><label for="id_form-1-ORDER">Order:</label></th><td><input type="number" name="form-1-ORDER" value="2" id="id_form-1-ORDER" /></td></tr>
|
|
<tr><th><label for="id_form-2-title">Title:</label></th><td><input type="text" name="form-2-title" id="id_form-2-title" /></td></tr>
|
|
<tr><th><label for="id_form-2-pub_date">Pub date:</label></th><td><input type="text" name="form-2-pub_date" id="id_form-2-pub_date" /></td></tr>
|
|
<tr><th><label for="id_form-2-ORDER">Order:</label></th><td><input type="number" name="form-2-ORDER" id="id_form-2-ORDER" /></td></tr>
|
|
|
|
This adds an additional field to each form. This new field is named ``ORDER``
|
|
and is an ``forms.IntegerField``. For the forms that came from the initial
|
|
data it automatically assigned them a numeric value. Let's look at what will
|
|
happen when the user changes these values::
|
|
|
|
>>> data = {
|
|
... 'form-TOTAL_FORMS': '3',
|
|
... 'form-INITIAL_FORMS': '2',
|
|
... 'form-MAX_NUM_FORMS': '',
|
|
... 'form-0-title': 'Article #1',
|
|
... 'form-0-pub_date': '2008-05-10',
|
|
... 'form-0-ORDER': '2',
|
|
... 'form-1-title': 'Article #2',
|
|
... 'form-1-pub_date': '2008-05-11',
|
|
... 'form-1-ORDER': '1',
|
|
... 'form-2-title': 'Article #3',
|
|
... 'form-2-pub_date': '2008-05-01',
|
|
... 'form-2-ORDER': '0',
|
|
... }
|
|
|
|
>>> formset = ArticleFormSet(data, initial=[
|
|
... {'title': 'Article #1', 'pub_date': datetime.date(2008, 5, 10)},
|
|
... {'title': 'Article #2', 'pub_date': datetime.date(2008, 5, 11)},
|
|
... ])
|
|
>>> formset.is_valid()
|
|
True
|
|
>>> for form in formset.ordered_forms:
|
|
... print(form.cleaned_data)
|
|
{'pub_date': datetime.date(2008, 5, 1), 'ORDER': 0, 'title': 'Article #3'}
|
|
{'pub_date': datetime.date(2008, 5, 11), 'ORDER': 1, 'title': 'Article #2'}
|
|
{'pub_date': datetime.date(2008, 5, 10), 'ORDER': 2, 'title': 'Article #1'}
|
|
|
|
``can_delete``
|
|
~~~~~~~~~~~~~~
|
|
|
|
.. attribute:: BaseFormSet.can_delete
|
|
|
|
Default: ``False``
|
|
|
|
Lets you create a formset with the ability to select forms for deletion::
|
|
|
|
>>> from django.forms.formsets import formset_factory
|
|
>>> from myapp.forms import ArticleForm
|
|
>>> ArticleFormSet = formset_factory(ArticleForm, can_delete=True)
|
|
>>> formset = ArticleFormSet(initial=[
|
|
... {'title': 'Article #1', 'pub_date': datetime.date(2008, 5, 10)},
|
|
... {'title': 'Article #2', 'pub_date': datetime.date(2008, 5, 11)},
|
|
... ])
|
|
>>> for form in formset:
|
|
.... print(form.as_table())
|
|
<input type="hidden" name="form-TOTAL_FORMS" value="3" id="id_form-TOTAL_FORMS" /><input type="hidden" name="form-INITIAL_FORMS" value="2" id="id_form-INITIAL_FORMS" /><input type="hidden" name="form-MAX_NUM_FORMS" id="id_form-MAX_NUM_FORMS" />
|
|
<tr><th><label for="id_form-0-title">Title:</label></th><td><input type="text" name="form-0-title" value="Article #1" id="id_form-0-title" /></td></tr>
|
|
<tr><th><label for="id_form-0-pub_date">Pub date:</label></th><td><input type="text" name="form-0-pub_date" value="2008-05-10" id="id_form-0-pub_date" /></td></tr>
|
|
<tr><th><label for="id_form-0-DELETE">Delete:</label></th><td><input type="checkbox" name="form-0-DELETE" id="id_form-0-DELETE" /></td></tr>
|
|
<tr><th><label for="id_form-1-title">Title:</label></th><td><input type="text" name="form-1-title" value="Article #2" id="id_form-1-title" /></td></tr>
|
|
<tr><th><label for="id_form-1-pub_date">Pub date:</label></th><td><input type="text" name="form-1-pub_date" value="2008-05-11" id="id_form-1-pub_date" /></td></tr>
|
|
<tr><th><label for="id_form-1-DELETE">Delete:</label></th><td><input type="checkbox" name="form-1-DELETE" id="id_form-1-DELETE" /></td></tr>
|
|
<tr><th><label for="id_form-2-title">Title:</label></th><td><input type="text" name="form-2-title" id="id_form-2-title" /></td></tr>
|
|
<tr><th><label for="id_form-2-pub_date">Pub date:</label></th><td><input type="text" name="form-2-pub_date" id="id_form-2-pub_date" /></td></tr>
|
|
<tr><th><label for="id_form-2-DELETE">Delete:</label></th><td><input type="checkbox" name="form-2-DELETE" id="id_form-2-DELETE" /></td></tr>
|
|
|
|
Similar to ``can_order`` this adds a new field to each form named ``DELETE``
|
|
and is a ``forms.BooleanField``. When data comes through marking any of the
|
|
delete fields you can access them with ``deleted_forms``::
|
|
|
|
>>> data = {
|
|
... 'form-TOTAL_FORMS': '3',
|
|
... 'form-INITIAL_FORMS': '2',
|
|
... 'form-MAX_NUM_FORMS': '',
|
|
... 'form-0-title': 'Article #1',
|
|
... 'form-0-pub_date': '2008-05-10',
|
|
... 'form-0-DELETE': 'on',
|
|
... 'form-1-title': 'Article #2',
|
|
... 'form-1-pub_date': '2008-05-11',
|
|
... 'form-1-DELETE': '',
|
|
... 'form-2-title': '',
|
|
... 'form-2-pub_date': '',
|
|
... 'form-2-DELETE': '',
|
|
... }
|
|
|
|
>>> formset = ArticleFormSet(data, initial=[
|
|
... {'title': 'Article #1', 'pub_date': datetime.date(2008, 5, 10)},
|
|
... {'title': 'Article #2', 'pub_date': datetime.date(2008, 5, 11)},
|
|
... ])
|
|
>>> [form.cleaned_data for form in formset.deleted_forms]
|
|
[{'DELETE': True, 'pub_date': datetime.date(2008, 5, 10), 'title': 'Article #1'}]
|
|
|
|
If you are using a :class:`ModelFormSet<django.forms.models.BaseModelFormSet>`,
|
|
model instances for deleted forms will be deleted when you call
|
|
``formset.save()``.
|
|
|
|
If you call ``formset.save(commit=False)``, objects will not be deleted
|
|
automatically. You'll need to call ``delete()`` on each of the
|
|
:attr:`formset.deleted_objects
|
|
<django.forms.models.BaseModelFormSet.deleted_objects>` to actually delete
|
|
them::
|
|
|
|
>>> instances = formset.save(commit=False)
|
|
>>> for obj in formset.deleted_objects:
|
|
... obj.delete()
|
|
|
|
On the other hand, if you are using a plain ``FormSet``, it's up to you to
|
|
handle ``formset.deleted_forms``, perhaps in your formset's ``save()`` method,
|
|
as there's no general notion of what it means to delete a form.
|
|
|
|
Adding additional fields to a formset
|
|
-------------------------------------
|
|
|
|
If you need to add additional fields to the formset this can be easily
|
|
accomplished. The formset base class provides an ``add_fields`` method. You
|
|
can simply override this method to add your own fields or even redefine the
|
|
default fields/attributes of the order and deletion fields::
|
|
|
|
>>> from django.forms.formsets import BaseFormSet
|
|
>>> from django.forms.formsets import formset_factory
|
|
>>> from myapp.forms import ArticleForm
|
|
>>> class BaseArticleFormSet(BaseFormSet):
|
|
... def add_fields(self, form, index):
|
|
... super(BaseArticleFormSet, self).add_fields(form, index)
|
|
... form.fields["my_field"] = forms.CharField()
|
|
|
|
>>> ArticleFormSet = formset_factory(ArticleForm, formset=BaseArticleFormSet)
|
|
>>> formset = ArticleFormSet()
|
|
>>> for form in formset:
|
|
... print(form.as_table())
|
|
<tr><th><label for="id_form-0-title">Title:</label></th><td><input type="text" name="form-0-title" id="id_form-0-title" /></td></tr>
|
|
<tr><th><label for="id_form-0-pub_date">Pub date:</label></th><td><input type="text" name="form-0-pub_date" id="id_form-0-pub_date" /></td></tr>
|
|
<tr><th><label for="id_form-0-my_field">My field:</label></th><td><input type="text" name="form-0-my_field" id="id_form-0-my_field" /></td></tr>
|
|
|
|
Using a formset in views and templates
|
|
--------------------------------------
|
|
|
|
Using a formset inside a view is as easy as using a regular ``Form`` class.
|
|
The only thing you will want to be aware of is making sure to use the
|
|
management form inside the template. Let's look at a sample view::
|
|
|
|
from django.forms.formsets import formset_factory
|
|
from django.shortcuts import render_to_response
|
|
from myapp.forms import ArticleForm
|
|
|
|
def manage_articles(request):
|
|
ArticleFormSet = formset_factory(ArticleForm)
|
|
if request.method == 'POST':
|
|
formset = ArticleFormSet(request.POST, request.FILES)
|
|
if formset.is_valid():
|
|
# do something with the formset.cleaned_data
|
|
pass
|
|
else:
|
|
formset = ArticleFormSet()
|
|
return render_to_response('manage_articles.html', {'formset': formset})
|
|
|
|
The ``manage_articles.html`` template might look like this:
|
|
|
|
.. code-block:: html+django
|
|
|
|
<form method="post" action="">
|
|
{{ formset.management_form }}
|
|
<table>
|
|
{% for form in formset %}
|
|
{{ form }}
|
|
{% endfor %}
|
|
</table>
|
|
</form>
|
|
|
|
However there's a slight shortcut for the above by letting the formset itself
|
|
deal with the management form:
|
|
|
|
.. code-block:: html+django
|
|
|
|
<form method="post" action="">
|
|
<table>
|
|
{{ formset }}
|
|
</table>
|
|
</form>
|
|
|
|
The above ends up calling the ``as_table`` method on the formset class.
|
|
|
|
.. _manually-rendered-can-delete-and-can-order:
|
|
|
|
Manually rendered ``can_delete`` and ``can_order``
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
If you manually render fields in the template, you can render
|
|
``can_delete`` parameter with ``{{ form.DELETE }}``:
|
|
|
|
.. code-block:: html+django
|
|
|
|
<form method="post" action="">
|
|
{{ formset.management_form }}
|
|
{% for form in formset %}
|
|
<ul>
|
|
<li>{{ form.title }}</li>
|
|
<li>{{ form.pub_date }}</li>
|
|
{% if formset.can_delete %}
|
|
<li>{{ form.DELETE }}</li>
|
|
{% endif %}
|
|
</ul>
|
|
{% endfor %}
|
|
</form>
|
|
|
|
|
|
Similarly, if the formset has the ability to order (``can_order=True``), it is
|
|
possible to render it with ``{{ form.ORDER }}``.
|
|
|
|
Using more than one formset in a view
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
You are able to use more than one formset in a view if you like. Formsets
|
|
borrow much of its behavior from forms. With that said you are able to use
|
|
``prefix`` to prefix formset form field names with a given value to allow
|
|
more than one formset to be sent to a view without name clashing. Lets take
|
|
a look at how this might be accomplished::
|
|
|
|
from django.forms.formsets import formset_factory
|
|
from django.shortcuts import render_to_response
|
|
from myapp.forms import ArticleForm, BookForm
|
|
|
|
def manage_articles(request):
|
|
ArticleFormSet = formset_factory(ArticleForm)
|
|
BookFormSet = formset_factory(BookForm)
|
|
if request.method == 'POST':
|
|
article_formset = ArticleFormSet(request.POST, request.FILES, prefix='articles')
|
|
book_formset = BookFormSet(request.POST, request.FILES, prefix='books')
|
|
if article_formset.is_valid() and book_formset.is_valid():
|
|
# do something with the cleaned_data on the formsets.
|
|
pass
|
|
else:
|
|
article_formset = ArticleFormSet(prefix='articles')
|
|
book_formset = BookFormSet(prefix='books')
|
|
return render_to_response('manage_articles.html', {
|
|
'article_formset': article_formset,
|
|
'book_formset': book_formset,
|
|
})
|
|
|
|
You would then render the formsets as normal. It is important to point out
|
|
that you need to pass ``prefix`` on both the POST and non-POST cases so that
|
|
it is rendered and processed correctly.
|