A formset is a layer of abstraction to work with multiple forms on the same\npage. It can be best compared to a data grid. Let’s say you have the following\nform:
\n>>> from django import forms\n>>> class ArticleForm(forms.Form):\n... title = forms.CharField()\n... pub_date = forms.DateField()\n...\nYou might want to allow the user to create several articles at once. To create\na formset out of an ArticleForm you would do:
>>> from django.forms import formset_factory\n>>> ArticleFormSet = formset_factory(ArticleForm)\nYou now have created a formset class named ArticleFormSet.\nInstantiating the formset gives you the ability to iterate over the forms\nin the formset and display them as you would with a regular form:
>>> formset = ArticleFormSet()\n>>> for form in formset:\n... print(form)\n...\n<div><label for="id_form-0-title">Title:</label><input type="text" name="form-0-title" id="id_form-0-title"></div>\n<div><label for="id_form-0-pub_date">Pub date:</label><input type="text" name="form-0-pub_date" id="id_form-0-pub_date"></div>\nAs you can see it only displayed one empty form. The number of empty forms\nthat is displayed is controlled by the extra parameter. By default,\nformset_factory() defines one extra form; the\nfollowing example will create a formset class to display two blank forms:
>>> ArticleFormSet = formset_factory(ArticleForm, extra=2)\nIterating over a formset will render the forms in the order they were\ncreated. You can change this order by providing an alternate implementation for\nthe __iter__() method.
Formsets can also be indexed into, which returns the corresponding form. If you\noverride __iter__, you will need to also override __getitem__ to have\nmatching behavior.
Initial data is what drives the main usability of a formset. As shown above\nyou can define the number of extra forms. What this means is that you are\ntelling the formset how many additional forms to show in addition to the\nnumber of forms it generates from the initial data. Let’s take a look at an\nexample:
\n>>> import datetime\n>>> from django.forms import formset_factory\n>>> from myapp.forms import ArticleForm\n>>> ArticleFormSet = formset_factory(ArticleForm, extra=2)\n>>> formset = ArticleFormSet(\n... initial=[\n... {\n... "title": "Django is now open source",\n... "pub_date": datetime.date.today(),\n... }\n... ]\n... )\n\n>>> for form in formset:\n... print(form)\n...\n<div><label for="id_form-0-title">Title:</label><input type="text" name="form-0-title" value="Django is now open source" id="id_form-0-title"></div>\n<div><label for="id_form-0-pub_date">Pub date:</label><input type="text" name="form-0-pub_date" value="2023-02-11" id="id_form-0-pub_date"></div>\n<div><label for="id_form-1-title">Title:</label><input type="text" name="form-1-title" id="id_form-1-title"></div>\n<div><label for="id_form-1-pub_date">Pub date:</label><input type="text" name="form-1-pub_date" id="id_form-1-pub_date"></div>\n<div><label for="id_form-2-title">Title:</label><input type="text" name="form-2-title" id="id_form-2-title"></div>\n<div><label for="id_form-2-pub_date">Pub date:</label><input type="text" name="form-2-pub_date" id="id_form-2-pub_date"></div>\nThere are now a total of three forms showing above. One for the initial data\nthat was passed in and two extra forms. Also note that we are passing in a\nlist of dictionaries as the initial data.
\nIf you use an initial for displaying a formset, you should pass the same\ninitial when processing that formset’s submission so that the formset can\ndetect which forms were changed by the user. For example, you might have\nsomething like: ArticleFormSet(request.POST, initial=[...]).
The max_num parameter to formset_factory()\ngives you the ability to limit the number of forms the formset will display:
>>> from django.forms import formset_factory\n>>> from myapp.forms import ArticleForm\n>>> ArticleFormSet = formset_factory(ArticleForm, extra=2, max_num=1)\n>>> formset = ArticleFormSet()\n>>> for form in formset:\n... print(form)\n...\n<div><label for="id_form-0-title">Title:</label><input type="text" name="form-0-title" id="id_form-0-title"></div>\n<div><label for="id_form-0-pub_date">Pub date:</label><input type="text" name="form-0-pub_date" id="id_form-0-pub_date"></div>\nIf the value of max_num is greater than the number of existing items in the\ninitial data, up to extra additional blank forms will be added to the\nformset, so long as the total number of forms does not exceed max_num. For\nexample, if extra=2 and max_num=2 and the formset is initialized with\none initial item, a form for the initial item and one blank form will be\ndisplayed.
If the number of items in the initial data exceeds max_num, all initial\ndata forms will be displayed regardless of the value of max_num and no\nextra forms will be displayed. For example, if extra=3 and max_num=1\nand the formset is initialized with two initial items, two forms with the\ninitial data will be displayed.
A max_num value of None (the default) puts a high limit on the number\nof 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\naffect validation. If validate_max=True is passed to the\nformset_factory(), then max_num will affect\nvalidation. See validate_max.
The absolute_max parameter to formset_factory() allows limiting the\nnumber of forms that can be instantiated when supplying POST data. This\nprotects against memory exhaustion attacks using forged POST requests:
>>> from django.forms.formsets import formset_factory\n>>> from myapp.forms import ArticleForm\n>>> ArticleFormSet = formset_factory(ArticleForm, absolute_max=1500)\n>>> data = {\n... "form-TOTAL_FORMS": "1501",\n... "form-INITIAL_FORMS": "0",\n... }\n>>> formset = ArticleFormSet(data)\n>>> len(formset.forms)\n1500\n>>> formset.is_valid()\nFalse\n>>> formset.non_form_errors()\n['Please submit at most 1000 forms.']\nWhen absolute_max is None, it defaults to max_num + 1000. (If\nmax_num is None, it defaults to 2000).
If absolute_max is less than max_num, a ValueError will be raised.
Validation with a formset is almost identical to a regular Form. There is\nan is_valid method on the formset to provide a convenient way to validate\nall forms in the formset:
>>> from django.forms import formset_factory\n>>> from myapp.forms import ArticleForm\n>>> ArticleFormSet = formset_factory(ArticleForm)\n>>> data = {\n... "form-TOTAL_FORMS": "1",\n... "form-INITIAL_FORMS": "0",\n... }\n>>> formset = ArticleFormSet(data)\n>>> formset.is_valid()\nTrue\nWe passed in no data to the formset which is resulting in a valid form. The\nformset is smart enough to ignore extra forms that were not changed. If we\nprovide an invalid article:
\n>>> data = {\n... "form-TOTAL_FORMS": "2",\n... "form-INITIAL_FORMS": "0",\n... "form-0-title": "Test",\n... "form-0-pub_date": "1904-06-16",\n... "form-1-title": "Test",\n... "form-1-pub_date": "", # <-- this date is missing but required\n... }\n>>> formset = ArticleFormSet(data)\n>>> formset.is_valid()\nFalse\n>>> formset.errors\n[{}, {'pub_date': ['This field is required.']}]\nAs we can see, formset.errors is a list whose entries correspond to the\nforms in the formset. Validation was performed for each of the two forms, and\nthe expected error message appears for the second item.
Just like when using a normal Form, each field in a formset’s forms may\ninclude HTML attributes such as maxlength for browser validation. However,\nform fields of formsets won’t include the required attribute as that\nvalidation may be incorrect when adding and deleting forms.
To check how many errors there are in the formset, we can use the\ntotal_error_count method:
>>> # Using the previous example\n>>> formset.errors\n[{}, {'pub_date': ['This field is required.']}]\n>>> len(formset.errors)\n2\n>>> formset.total_error_count()\n1\nWe can also check if form data differs from the initial data (i.e. the form was\nsent without any data):
\n>>> data = {\n... "form-TOTAL_FORMS": "1",\n... "form-INITIAL_FORMS": "0",\n... "form-0-title": "",\n... "form-0-pub_date": "",\n... }\n>>> formset = ArticleFormSet(data)\n>>> formset.has_changed()\nFalse\nManagementFormLink para este cabeçalho#You may have noticed the additional data (form-TOTAL_FORMS,\nform-INITIAL_FORMS) that was required in the formset’s data above. This\ndata is required for the ManagementForm. This form is used by the formset\nto manage the collection of forms contained in the formset. If you don’t\nprovide this management data, the formset will be invalid:
>>> data = {\n... "form-0-title": "Test",\n... "form-0-pub_date": "",\n... }\n>>> formset = ArticleFormSet(data)\n>>> formset.is_valid()\nFalse\nIt is used to keep track of how many form instances are being displayed. If\nyou are adding new forms via JavaScript, you should increment the count fields\nin this form as well. On the other hand, if you are using JavaScript to allow\ndeletion of existing objects, then you need to ensure the ones being removed\nare properly marked for deletion by including form-#-DELETE in the POST\ndata. It is expected that all forms are present in the POST data regardless.
The management form is available as an attribute of the formset\nitself. When rendering a formset in a template, you can include all\nthe management data by rendering {{ my_formset.management_form }}\n(substituting the name of your formset as appropriate).
total_form_count and initial_form_countLink para este cabeçalho#BaseFormSet has a couple of methods that are closely related to the\nManagementForm, total_form_count and initial_form_count.
total_form_count returns the total number of forms in this formset.\ninitial_form_count returns the number of forms in the formset that were\npre-filled, and is also used to determine how many forms are required. You\nwill probably never need to override either of these methods, so please be\nsure you understand what they do before doing so.
empty_formLink para este cabeçalho#BaseFormSet provides an additional attribute empty_form which returns\na form instance with a prefix of __prefix__ for easier use in dynamic\nforms with JavaScript.
error_messagesLink para este cabeçalho#The error_messages argument lets you override the default messages that the\nformset will raise. Pass in a dictionary with keys matching the error messages\nyou want to override. Error message keys include 'too_few_forms',\n'too_many_forms', and 'missing_management_form'. The\n'too_few_forms' and 'too_many_forms' error messages may contain\n%(num)d, which will be replaced with min_num and max_num,\nrespectively.
For example, here is the default error message when the\nmanagement form is missing:
\n>>> formset = ArticleFormSet({})\n>>> formset.is_valid()\nFalse\n>>> formset.non_form_errors()\n['ManagementForm data is missing or has been tampered with. Missing fields: form-TOTAL_FORMS, form-INITIAL_FORMS. You may need to file a bug report if the issue persists.']\nAnd here is a custom error message:
\n>>> formset = ArticleFormSet(\n... {}, error_messages={"missing_management_form": "Sorry, something went wrong."}\n... )\n>>> formset.is_valid()\nFalse\n>>> formset.non_form_errors()\n['Sorry, something went wrong.']\nA formset has a clean method similar to the one on a Form class. This\nis where you define your own validation that works at the formset level:
>>> from django.core.exceptions import ValidationError\n>>> from django.forms import BaseFormSet\n>>> from django.forms import formset_factory\n>>> from myapp.forms import ArticleForm\n\n>>> class BaseArticleFormSet(BaseFormSet):\n... def clean(self):\n... """Checks that no two articles have the same title."""\n... if any(self.errors):\n... # Don't bother validating the formset unless each form is valid on its own\n... return\n... titles = set()\n... for form in self.forms:\n... if self.can_delete and self._should_delete_form(form):\n... continue\n... title = form.cleaned_data.get("title")\n... if title in titles:\n... raise ValidationError("Articles in a set must have distinct titles.")\n... titles.add(title)\n...\n\n>>> ArticleFormSet = formset_factory(ArticleForm, formset=BaseArticleFormSet)\n>>> data = {\n... "form-TOTAL_FORMS": "2",\n... "form-INITIAL_FORMS": "0",\n... "form-0-title": "Test",\n... "form-0-pub_date": "1904-06-16",\n... "form-1-title": "Test",\n... "form-1-pub_date": "1912-06-23",\n... }\n>>> formset = ArticleFormSet(data)\n>>> formset.is_valid()\nFalse\n>>> formset.errors\n[{}, {}]\n>>> formset.non_form_errors()\n['Articles in a set must have distinct titles.']\nThe formset clean method is called after all the Form.clean methods\nhave been called. The errors will be found using the non_form_errors()\nmethod on the formset.
Non-form errors will be rendered with an additional class of nonform to\nhelp distinguish them from form-specific errors. For example,\n{{ formset.non_form_errors }} would look like:
<ul class="errorlist nonform">\n <li>Articles in a set must have distinct titles.</li>\n</ul>\nDjango provides a couple ways to validate the minimum or maximum number of\nsubmitted forms. Applications which need more customizable validation of the\nnumber of forms should use custom formset validation.
\nvalidate_maxLink para este cabeçalho#If validate_max=True is passed to\nformset_factory(), validation will also check\nthat the number of forms in the data set, minus those marked for\ndeletion, is less than or equal to max_num.
>>> from django.forms import formset_factory\n>>> from myapp.forms import ArticleForm\n>>> ArticleFormSet = formset_factory(ArticleForm, max_num=1, validate_max=True)\n>>> data = {\n... "form-TOTAL_FORMS": "2",\n... "form-INITIAL_FORMS": "0",\n... "form-0-title": "Test",\n... "form-0-pub_date": "1904-06-16",\n... "form-1-title": "Test 2",\n... "form-1-pub_date": "1912-06-23",\n... }\n>>> formset = ArticleFormSet(data)\n>>> formset.is_valid()\nFalse\n>>> formset.errors\n[{}, {}]\n>>> formset.non_form_errors()\n['Please submit at most 1 form.']\nvalidate_max=True validates against max_num strictly even if\nmax_num was exceeded because the amount of initial data supplied was\nexcessive.
The error message can be customized by passing the 'too_many_forms' message\nto the error_messages argument.
validate_minLink para este cabeçalho#If validate_min=True is passed to\nformset_factory(), validation will also check\nthat the number of forms in the data set, minus those marked for\ndeletion, is greater than or equal to min_num.
>>> from django.forms import formset_factory\n>>> from myapp.forms import ArticleForm\n>>> ArticleFormSet = formset_factory(ArticleForm, min_num=3, validate_min=True)\n>>> data = {\n... "form-TOTAL_FORMS": "2",\n... "form-INITIAL_FORMS": "0",\n... "form-0-title": "Test",\n... "form-0-pub_date": "1904-06-16",\n... "form-1-title": "Test 2",\n... "form-1-pub_date": "1912-06-23",\n... }\n>>> formset = ArticleFormSet(data)\n>>> formset.is_valid()\nFalse\n>>> formset.errors\n[{}, {}]\n>>> formset.non_form_errors()\n['Please submit at least 3 forms.']\nThe error message can be customized by passing the 'too_few_forms' message\nto the error_messages argument.
The formset_factory() provides two optional\nparameters can_order and can_delete to help with ordering of forms in\nformsets and deletion of forms from a formset.
can_orderLink para este cabeçalho#Default: False
Lets you create a formset with the ability to order:
\n>>> from django.forms import formset_factory\n>>> from myapp.forms import ArticleForm\n>>> ArticleFormSet = formset_factory(ArticleForm, can_order=True)\n>>> formset = ArticleFormSet(\n... initial=[\n... {"title": "Article #1", "pub_date": datetime.date(2008, 5, 10)},\n... {"title": "Article #2", "pub_date": datetime.date(2008, 5, 11)},\n... ]\n... )\n>>> for form in formset:\n... print(form)\n...\n<div><label for="id_form-0-title">Title:</label><input type="text" name="form-0-title" value="Article #1" id="id_form-0-title"></div>\n<div><label for="id_form-0-pub_date">Pub date:</label><input type="text" name="form-0-pub_date" value="2008-05-10" id="id_form-0-pub_date"></div>\n<div><label for="id_form-0-ORDER">Order:</label><input type="number" name="form-0-ORDER" value="1" id="id_form-0-ORDER"></div>\n<div><label for="id_form-1-title">Title:</label><input type="text" name="form-1-title" value="Article #2" id="id_form-1-title"></div>\n<div><label for="id_form-1-pub_date">Pub date:</label><input type="text" name="form-1-pub_date" value="2008-05-11" id="id_form-1-pub_date"></div>\n<div><label for="id_form-1-ORDER">Order:</label><input type="number" name="form-1-ORDER" value="2" id="id_form-1-ORDER"></div>\n<div><label for="id_form-2-title">Title:</label><input type="text" name="form-2-title" id="id_form-2-title"></div>\n<div><label for="id_form-2-pub_date">Pub date:</label><input type="text" name="form-2-pub_date" id="id_form-2-pub_date"></div>\n<div><label for="id_form-2-ORDER">Order:</label><input type="number" name="form-2-ORDER" id="id_form-2-ORDER"></div>\nThis adds an additional field to each form. This new field is named ORDER\nand is an forms.IntegerField. For the forms that came from the initial\ndata it automatically assigned them a numeric value. Let’s look at what will\nhappen when the user changes these values:
>>> data = {\n... "form-TOTAL_FORMS": "3",\n... "form-INITIAL_FORMS": "2",\n... "form-0-title": "Article #1",\n... "form-0-pub_date": "2008-05-10",\n... "form-0-ORDER": "2",\n... "form-1-title": "Article #2",\n... "form-1-pub_date": "2008-05-11",\n... "form-1-ORDER": "1",\n... "form-2-title": "Article #3",\n... "form-2-pub_date": "2008-05-01",\n... "form-2-ORDER": "0",\n... }\n\n>>> formset = ArticleFormSet(\n... data,\n... initial=[\n... {"title": "Article #1", "pub_date": datetime.date(2008, 5, 10)},\n... {"title": "Article #2", "pub_date": datetime.date(2008, 5, 11)},\n... ],\n... )\n>>> formset.is_valid()\nTrue\n>>> for form in formset.ordered_forms:\n... print(form.cleaned_data)\n...\n{'pub_date': datetime.date(2008, 5, 1), 'ORDER': 0, 'title': 'Article #3'}\n{'pub_date': datetime.date(2008, 5, 11), 'ORDER': 1, 'title': 'Article #2'}\n{'pub_date': datetime.date(2008, 5, 10), 'ORDER': 2, 'title': 'Article #1'}\nBaseFormSet also provides an\nordering_widget attribute and\nget_ordering_widget() method that\ncontrol the widget used with\ncan_order.
ordering_widgetLink para este cabeçalho#Default: NumberInput
Set ordering_widget to specify the widget class to be used with\ncan_order:
>>> from django.forms import BaseFormSet, formset_factory\n>>> from myapp.forms import ArticleForm\n>>> class BaseArticleFormSet(BaseFormSet):\n... ordering_widget = HiddenInput\n...\n\n>>> ArticleFormSet = formset_factory(\n... ArticleForm, formset=BaseArticleFormSet, can_order=True\n... )\nget_ordering_widgetLink para este cabeçalho#Override get_ordering_widget() if you need to provide a widget instance for\nuse with can_order:
>>> from django.forms import BaseFormSet, formset_factory\n>>> from myapp.forms import ArticleForm\n>>> class BaseArticleFormSet(BaseFormSet):\n... def get_ordering_widget(self):\n... return HiddenInput(attrs={"class": "ordering"})\n...\n\n>>> ArticleFormSet = formset_factory(\n... ArticleForm, formset=BaseArticleFormSet, can_order=True\n... )\ncan_deleteLink para este cabeçalho#Default: False
Lets you create a formset with the ability to select forms for deletion:
\n>>> from django.forms import formset_factory\n>>> from myapp.forms import ArticleForm\n>>> ArticleFormSet = formset_factory(ArticleForm, can_delete=True)\n>>> formset = ArticleFormSet(\n... initial=[\n... {"title": "Article #1", "pub_date": datetime.date(2008, 5, 10)},\n... {"title": "Article #2", "pub_date": datetime.date(2008, 5, 11)},\n... ]\n... )\n>>> for form in formset:\n... print(form)\n...\n<div><label for="id_form-0-title">Title:</label><input type="text" name="form-0-title" value="Article #1" id="id_form-0-title"></div>\n<div><label for="id_form-0-pub_date">Pub date:</label><input type="text" name="form-0-pub_date" value="2008-05-10" id="id_form-0-pub_date"></div>\n<div><label for="id_form-0-DELETE">Delete:</label><input type="checkbox" name="form-0-DELETE" id="id_form-0-DELETE"></div>\n<div><label for="id_form-1-title">Title:</label><input type="text" name="form-1-title" value="Article #2" id="id_form-1-title"></div>\n<div><label for="id_form-1-pub_date">Pub date:</label><input type="text" name="form-1-pub_date" value="2008-05-11" id="id_form-1-pub_date"></div>\n<div><label for="id_form-1-DELETE">Delete:</label><input type="checkbox" name="form-1-DELETE" id="id_form-1-DELETE"></div>\n<div><label for="id_form-2-title">Title:</label><input type="text" name="form-2-title" id="id_form-2-title"></div>\n<div><label for="id_form-2-pub_date">Pub date:</label><input type="text" name="form-2-pub_date" id="id_form-2-pub_date"></div>\n<div><label for="id_form-2-DELETE">Delete:</label><input type="checkbox" name="form-2-DELETE" id="id_form-2-DELETE"></div>\nSimilar to can_order this adds a new field to each form named DELETE\nand is a forms.BooleanField. When data comes through marking any of the\ndelete fields you can access them with deleted_forms:
>>> data = {\n... "form-TOTAL_FORMS": "3",\n... "form-INITIAL_FORMS": "2",\n... "form-0-title": "Article #1",\n... "form-0-pub_date": "2008-05-10",\n... "form-0-DELETE": "on",\n... "form-1-title": "Article #2",\n... "form-1-pub_date": "2008-05-11",\n... "form-1-DELETE": "",\n... "form-2-title": "",\n... "form-2-pub_date": "",\n... "form-2-DELETE": "",\n... }\n\n>>> formset = ArticleFormSet(\n... data,\n... initial=[\n... {"title": "Article #1", "pub_date": datetime.date(2008, 5, 10)},\n... {"title": "Article #2", "pub_date": datetime.date(2008, 5, 11)},\n... ],\n... )\n>>> [form.cleaned_data for form in formset.deleted_forms]\n[{'DELETE': True, 'pub_date': datetime.date(2008, 5, 10), 'title': 'Article #1'}]\nIf you are using a ModelFormSet,\nmodel instances for deleted forms will be deleted when you call\nformset.save().
If you call formset.save(commit=False), objects will not be deleted\nautomatically. You’ll need to call delete() on each of the\nformset.deleted_objects to actually delete\nthem:
>>> instances = formset.save(commit=False)\n>>> for obj in formset.deleted_objects:\n... obj.delete()\n...\nOn the other hand, if you are using a plain FormSet, it’s up to you to\nhandle formset.deleted_forms, perhaps in your formset’s save() method,\nas there’s no general notion of what it means to delete a form.
BaseFormSet also provides a\ndeletion_widget attribute and\nget_deletion_widget() method that\ncontrol the widget used with\ncan_delete.
deletion_widgetLink para este cabeçalho#Default: CheckboxInput
Set deletion_widget to specify the widget class to be used with\ncan_delete:
>>> from django.forms import BaseFormSet, formset_factory\n>>> from myapp.forms import ArticleForm\n>>> class BaseArticleFormSet(BaseFormSet):\n... deletion_widget = HiddenInput\n...\n\n>>> ArticleFormSet = formset_factory(\n... ArticleForm, formset=BaseArticleFormSet, can_delete=True\n... )\nget_deletion_widgetLink para este cabeçalho#Override get_deletion_widget() if you need to provide a widget instance for\nuse with can_delete:
>>> from django.forms import BaseFormSet, formset_factory\n>>> from myapp.forms import ArticleForm\n>>> class BaseArticleFormSet(BaseFormSet):\n... def get_deletion_widget(self):\n... return HiddenInput(attrs={"class": "deletion"})\n...\n\n>>> ArticleFormSet = formset_factory(\n... ArticleForm, formset=BaseArticleFormSet, can_delete=True\n... )\ncan_delete_extraLink para este cabeçalho#Default: True
While setting can_delete=True, specifying can_delete_extra=False will\nremove the option to delete extra forms.
If you need to add additional fields to the formset this can be easily\naccomplished. The formset base class provides an add_fields method. You\ncan override this method to add your own fields or even redefine the default\nfields/attributes of the order and deletion fields:
>>> from django.forms import BaseFormSet\n>>> from django.forms import formset_factory\n>>> from myapp.forms import ArticleForm\n>>> class BaseArticleFormSet(BaseFormSet):\n... def add_fields(self, form, index):\n... super().add_fields(form, index)\n... form.fields["my_field"] = forms.CharField()\n...\n\n>>> ArticleFormSet = formset_factory(ArticleForm, formset=BaseArticleFormSet)\n>>> formset = ArticleFormSet()\n>>> for form in formset:\n... print(form)\n...\n<div><label for="id_form-0-title">Title:</label><input type="text" name="form-0-title" id="id_form-0-title"></div>\n<div><label for="id_form-0-pub_date">Pub date:</label><input type="text" name="form-0-pub_date" id="id_form-0-pub_date"></div>\n<div><label for="id_form-0-my_field">My field:</label><input type="text" name="form-0-my_field" id="id_form-0-my_field"></div>\nSometimes your form class takes custom parameters, like MyArticleForm.\nYou can pass this parameter when instantiating the formset:
>>> from django.forms import BaseFormSet\n>>> from django.forms import formset_factory\n>>> from myapp.forms import ArticleForm\n\n>>> class MyArticleForm(ArticleForm):\n... def __init__(self, *args, user, **kwargs):\n... self.user = user\n... super().__init__(*args, **kwargs)\n...\n\n>>> ArticleFormSet = formset_factory(MyArticleForm)\n>>> formset = ArticleFormSet(form_kwargs={"user": request.user})\nThe form_kwargs may also depend on the specific form instance. The formset\nbase class provides a get_form_kwargs method. The method takes a single\nargument - the index of the form in the formset. The index is None for the\nempty_form:
>>> from django.forms import BaseFormSet\n>>> from django.forms import formset_factory\n\n>>> class BaseArticleFormSet(BaseFormSet):\n... def get_form_kwargs(self, index):\n... kwargs = super().get_form_kwargs(index)\n... kwargs["custom_kwarg"] = index\n... return kwargs\n...\n\n>>> ArticleFormSet = formset_factory(MyArticleForm, formset=BaseArticleFormSet)\n>>> formset = ArticleFormSet()\nIn the rendered HTML, formsets include a prefix on each field’s name. By\ndefault, the prefix is 'form', but it can be customized using the formset’s\nprefix argument.
For example, in the default case, you might see:
\n<label for="id_form-0-title">Title:</label>\n<input type="text" name="form-0-title" id="id_form-0-title">\nBut with ArticleFormset(prefix='article') that becomes:
<label for="id_article-0-title">Title:</label>\n<input type="text" name="article-0-title" id="id_article-0-title">\nThis is useful if you want to use more than one formset in a view.
\nFormsets have the following attributes and methods associated with rendering:
\nSpecifies the renderer to use for the\nformset. Defaults to the renderer specified by the FORM_RENDERER\nsetting.
The name of the template rendered if the formset is cast into a string,\ne.g. via print(formset) or in a template via {{ formset }}.
By default, a property returning the value of the renderer’s\nformset_template_name. You may\nset it as a string template name in order to override that for a particular\nformset class.
This template will be used to render the formset’s management form, and\nthen each form in the formset as per the template defined by the form’s\ntemplate_name.
The name of the template used when calling as_div(). By default this\nis "django/forms/formsets/div.html". This template renders the\nformset’s management form and then each form in the formset as per the\nform’s as_div() method.
The name of the template used when calling as_p(). By default this\nis "django/forms/formsets/p.html". This template renders the formset’s\nmanagement form and then each form in the formset as per the form’s\nas_p() method.
The name of the template used when calling as_table(). By default\nthis is "django/forms/formsets/table.html". This template renders the\nformset’s management form and then each form in the formset as per the\nform’s as_table() method.
The name of the template used when calling as_ul(). By default this\nis "django/forms/formsets/ul.html". This template renders the formset’s\nmanagement form and then each form in the formset as per the form’s\nas_ul() method.
Returns the context for rendering a formset in a template.
\nThe available context is:
\nformset : The instance of the formset.
The render method is called by __str__ as well as the as_div(),\nas_p(), as_ul(), and as_table() methods. All arguments\nare optional and will default to:
template_name: template_name
context: Value returned by get_context()
renderer: Value returned by renderer
Renders the formset with the template_name_div template.
Renders the formset with the template_name_p template.
Renders the formset with the template_name_table template.
Renders the formset with the template_name_ul template.
Using a formset inside a view is not very different from using a regular\nForm class. The only thing you will want to be aware of is making sure to\nuse the management form inside the template. Let’s look at a sample view:
from django.forms import formset_factory\nfrom django.shortcuts import render\nfrom myapp.forms import ArticleForm\n\n\ndef manage_articles(request):\n ArticleFormSet = formset_factory(ArticleForm)\n if request.method == "POST":\n formset = ArticleFormSet(request.POST, request.FILES)\n if formset.is_valid():\n # do something with the formset.cleaned_data\n pass\n else:\n formset = ArticleFormSet()\n return render(request, "manage_articles.html", {"formset": formset})\nThe manage_articles.html template might look like this:
<form method="post">\n {{ formset.management_form }}\n <table>\n {% for form in formset %}\n {{ form }}\n {% endfor %}\n </table>\n</form>\nHowever there’s a slight shortcut for the above by letting the formset itself\ndeal with the management form:
\n<form method="post">\n <table>\n {{ formset }}\n </table>\n</form>\nThe above ends up calling the BaseFormSet.render() method on the formset\nclass. This renders the formset using the template specified by the\ntemplate_name attribute. Similar to forms, by default the\nformset will be rendered as_table, with other helper methods of as_p\nand as_ul being available. The rendering of the formset can be customized\nby specifying the template_name attribute, or more generally by\noverriding the default template.
can_delete and can_orderLink para este cabeçalho#If you manually render fields in the template, you can render\ncan_delete parameter with {{ form.DELETE }}:
<form method="post">\n {{ formset.management_form }}\n {% for form in formset %}\n <ul>\n <li>{{ form.title }}</li>\n <li>{{ form.pub_date }}</li>\n {% if formset.can_delete %}\n <li>{{ form.DELETE }}</li>\n {% endif %}\n </ul>\n {% endfor %}\n</form>\nSimilarly, if the formset has the ability to order (can_order=True), it is\npossible to render it with {{ form.ORDER }}.
You are able to use more than one formset in a view if you like. Formsets\nborrow much of its behavior from forms. With that said you are able to use\nprefix to prefix formset form field names with a given value to allow\nmore than one formset to be sent to a view without name clashing. Let’s take\na look at how this might be accomplished:
from django.forms import formset_factory\nfrom django.shortcuts import render\nfrom myapp.forms import ArticleForm, BookForm\n\n\ndef manage_articles(request):\n ArticleFormSet = formset_factory(ArticleForm)\n BookFormSet = formset_factory(BookForm)\n if request.method == "POST":\n article_formset = ArticleFormSet(request.POST, request.FILES, prefix="articles")\n book_formset = BookFormSet(request.POST, request.FILES, prefix="books")\n if article_formset.is_valid() and book_formset.is_valid():\n # do something with the cleaned_data on the formsets.\n pass\n else:\n article_formset = ArticleFormSet(prefix="articles")\n book_formset = BookFormSet(prefix="books")\n return render(\n request,\n "manage_articles.html",\n {\n "article_formset": article_formset,\n "book_formset": book_formset,\n },\n )\nYou would then render the formsets as normal. It is important to point out\nthat you need to pass prefix on both the POST and non-POST cases so that\nit is rendered and processed correctly.
Each formset’s prefix replaces the default form\nprefix that’s added to each field’s name and id HTML attributes.