Form fields

class Field(**kwargs)[ソース]

Form クラスを作成時の一番重要な部分は、form のフィールド (field) の定義です。各フィールドにはカスタムの検証ロジックがあり、他にいくつかのフックもあります。

Field.clean(value)[ソース]

Field クラスは主に Form クラス内で使われますが、インスタンスを作って直接使ったほうが便利に使えることもあります。各 Field インスタンスは1つの引数をとる clean() メソッドを持っており、次の例に示すように、django.forms.ValidationError 例外を発生したり、クリーンな値を返してくれます。

>>> from django import forms
>>> f = forms.EmailField()
>>> f.clean('foo@example.com')
'foo@example.com'
>>> f.clean('invalid email address')
Traceback (most recent call last):
...
ValidationError: ['Enter a valid email address.']

field のコアとなる引数

Field クラスのコンストラクタは少なくとも以下の引数を受け付けます。Field クラスによっては追加のフィールド固有の引数も取れることがありますが、以下に説明する引数は 常に 取ることができます。

required

Field.required

By default, each Field class assumes the value is required, so if you pass an empty value -- either None or the empty string ("") -- then clean() will raise a ValidationError exception:

>>> from django import forms
>>> f = forms.CharField()
>>> f.clean('foo')
'foo'
>>> f.clean('')
Traceback (most recent call last):
...
ValidationError: ['This field is required.']
>>> f.clean(None)
Traceback (most recent call last):
...
ValidationError: ['This field is required.']
>>> f.clean(' ')
' '
>>> f.clean(0)
'0'
>>> f.clean(True)
'True'
>>> f.clean(False)
'False'

To specify that a field is not required, pass required=False to the Field constructor:

>>> f = forms.CharField(required=False)
>>> f.clean('foo')
'foo'
>>> f.clean('')
''
>>> f.clean(None)
''
>>> f.clean(0)
'0'
>>> f.clean(True)
'True'
>>> f.clean(False)
'False'

If a Field has required=False and you pass clean() an empty value, then clean() will return a normalized empty value rather than raising ValidationError. For CharField, this will be an empty string. For other Field classes, it might be None. (This varies from field to field.)

Widgets of required form fields have the required HTML attribute. Set the Form.use_required_attribute attribute to False to disable it. The required attribute isn't included on forms of formsets because the browser validation may not be correct when adding and deleting formsets.

label

Field.label

label 属性は、フィールドに対する "人が読みやすい" ラベルを指定します。このラベルは FieldForm 内で表示されるときに使用されます。

上述の "HTML としてフォームを出力する" で説明したとおり、Field に対するデフォルトのラベルはアンダースコアを空白に、また単語の最初の小文字を大文字に変換して生成されます。 デフォルトではない文字列を表示したい場合には、label を指定してください。

以下は、label を 2 つのフィールドに実装した Form の実例です。出力を見やすくするため auto_id=False を指定しています。

>>> from django import forms
>>> class CommentForm(forms.Form):
...     name = forms.CharField(label='Your name')
...     url = forms.URLField(label='Your website', required=False)
...     comment = forms.CharField()
>>> f = CommentForm(auto_id=False)
>>> print(f)
<tr><th>Your name:</th><td><input type="text" name="name" required /></td></tr>
<tr><th>Your website:</th><td><input type="url" name="url" /></td></tr>
<tr><th>Comment:</th><td><input type="text" name="comment" required /></td></tr>

label_suffix

Field.label_suffix

label_suffix 属性は、フィールドごとの label_suffix をオーバーライドします:

>>> class ContactForm(forms.Form):
...     age = forms.IntegerField()
...     nationality = forms.CharField()
...     captcha_answer = forms.IntegerField(label='2 + 2', label_suffix=' =')
>>> f = ContactForm(label_suffix='?')
>>> print(f.as_p())
<p><label for="id_age">Age?</label> <input id="id_age" name="age" type="number" required /></p>
<p><label for="id_nationality">Nationality?</label> <input id="id_nationality" name="nationality" type="text" required /></p>
<p><label for="id_captcha_answer">2 + 2 =</label> <input id="id_captcha_answer" name="captcha_answer" type="number" required /></p>

initial

Field.initial

initial 属性は、Field が結びつけられていない Form で表示されるときに使われる初期値を指定します。

動的に初期値を指定する方法は、Form.initial パラメータを参照してください。

The use-case for this is when you want to display an "empty" form in which a field is initialized to a particular value. For example:

>>> from django import forms
>>> class CommentForm(forms.Form):
...     name = forms.CharField(initial='Your name')
...     url = forms.URLField(initial='http://')
...     comment = forms.CharField()
>>> f = CommentForm(auto_id=False)
>>> print(f)
<tr><th>Name:</th><td><input type="text" name="name" value="Your name" required /></td></tr>
<tr><th>Url:</th><td><input type="url" name="url" value="http://" required /></td></tr>
<tr><th>Comment:</th><td><input type="text" name="comment" required /></td></tr>

You may be thinking, why not just pass a dictionary of the initial values as data when displaying the form? Well, if you do that, you'll trigger validation, and the HTML output will include any validation errors:

>>> class CommentForm(forms.Form):
...     name = forms.CharField()
...     url = forms.URLField()
...     comment = forms.CharField()
>>> default_data = {'name': 'Your name', 'url': 'http://'}
>>> f = CommentForm(default_data, auto_id=False)
>>> print(f)
<tr><th>Name:</th><td><input type="text" name="name" value="Your name" required /></td></tr>
<tr><th>Url:</th><td><ul class="errorlist"><li>Enter a valid URL.</li></ul><input type="url" name="url" value="http://" required /></td></tr>
<tr><th>Comment:</th><td><ul class="errorlist"><li>This field is required.</li></ul><input type="text" name="comment" required /></td></tr>

This is why initial values are only displayed for unbound forms. For bound forms, the HTML output will use the bound data.

Also note that initial values are not used as "fallback" data in validation if a particular field's value is not given. initial values are only intended for initial form display:

>>> class CommentForm(forms.Form):
...     name = forms.CharField(initial='Your name')
...     url = forms.URLField(initial='http://')
...     comment = forms.CharField()
>>> data = {'name': '', 'url': '', 'comment': 'Foo'}
>>> f = CommentForm(data)
>>> f.is_valid()
False
# The form does *not* fall back to using the initial values.
>>> f.errors
{'url': ['This field is required.'], 'name': ['This field is required.']}

Instead of a constant, you can also pass any callable:

>>> import datetime
>>> class DateForm(forms.Form):
...     day = forms.DateField(initial=datetime.date.today)
>>> print(DateForm())
<tr><th>Day:</th><td><input type="text" name="day" value="12/23/2008" required /><td></tr>

The callable will be evaluated only when the unbound form is displayed, not when it is defined.

widget

Field.widget

widget 引数は、Field をレンダリングするときに使う Widget クラスを指定します。詳しくは ウィジェット を参照してください。

help_text

Field.help_text

help_text 引数は、Field を説明するテキストを指定します。help_text を指定した場合、容易な Form メソッド (例えば as_ul()) で Field がレンダリングされるときに、Field の隣に表示されます。

モデルフィールドの help_text と同じく、値は自動的に生成されるフォーム内で HTML 用にエスケープされません。

Here's a full example Form that implements help_text for two of its fields. We've specified auto_id=False to simplify the output:

>>> from django import forms
>>> class HelpTextContactForm(forms.Form):
...     subject = forms.CharField(max_length=100, help_text='100 characters max.')
...     message = forms.CharField()
...     sender = forms.EmailField(help_text='A valid email address, please.')
...     cc_myself = forms.BooleanField(required=False)
>>> f = HelpTextContactForm(auto_id=False)
>>> print(f.as_table())
<tr><th>Subject:</th><td><input type="text" name="subject" maxlength="100" required /><br /><span class="helptext">100 characters max.</span></td></tr>
<tr><th>Message:</th><td><input type="text" name="message" required /></td></tr>
<tr><th>Sender:</th><td><input type="email" name="sender" required /><br />A valid email address, please.</td></tr>
<tr><th>Cc myself:</th><td><input type="checkbox" name="cc_myself" /></td></tr>
>>> print(f.as_ul()))
<li>Subject: <input type="text" name="subject" maxlength="100" required /> <span class="helptext">100 characters max.</span></li>
<li>Message: <input type="text" name="message" required /></li>
<li>Sender: <input type="email" name="sender" required /> A valid email address, please.</li>
<li>Cc myself: <input type="checkbox" name="cc_myself" /></li>
>>> print(f.as_p())
<p>Subject: <input type="text" name="subject" maxlength="100" required /> <span class="helptext">100 characters max.</span></p>
<p>Message: <input type="text" name="message" required /></p>
<p>Sender: <input type="email" name="sender" required /> A valid email address, please.</p>
<p>Cc myself: <input type="checkbox" name="cc_myself" /></p>

error_messages

Field.error_messages

The error_messages argument lets you override the default messages that the field will raise. Pass in a dictionary with keys matching the error messages you want to override. For example, here is the default error message:

>>> from django import forms
>>> generic = forms.CharField()
>>> generic.clean('')
Traceback (most recent call last):
  ...
ValidationError: ['This field is required.']

And here is a custom error message:

>>> name = forms.CharField(error_messages={'required': 'Please enter your name'})
>>> name.clean('')
Traceback (most recent call last):
  ...
ValidationError: ['Please enter your name']

In the built-in Field classes section below, each Field defines the error message keys it uses.

validators

Field.validators

validators 引数は、フィールドに対するバリデーション関数のリストを指定します。

詳しくは validators documentation を参照してください。

localize

Field.localize

localize 引数は、form データの入力とレンダリングした出力のローカライゼーションを有効にします。

詳しくは 書式のローカライゼーション ドキュメントを読んでください。

disabled

Field.disabled

disabled はブール値の引数を取ります。 True にセットされた場合、フォームのフィールドを disabled HTML 属性を使って無効化し、ユーザーが編集できないようにします。たとえユーザーが勝手にフィールドの値を書き換えてサーバーに送信したとしても、フォームの初期データを使い、書き換えられたデータは無視します。

フィールドのデータの変更チェック

has_changed()

Field.has_changed()[ソース]

has_changed() メソッドは、フィールドの値が最初の値から変更されたかどうかを確認するのに使用します。True または False を返します。

詳しくは Form.has_changed() ドキュメントを読んでください。

ビルトインの Field クラス

Naturally, the forms library comes with a set of Field classes that represent common validation needs. This section documents each built-in field.

For each field, we describe the default widget used if you don't specify widget. We also specify the value returned when you provide an empty value (see the section on required above to understand what that means).

BooleanField

class BooleanField(**kwargs)[ソース]
  • デフォルトのウィジェット: CheckboxInput
  • 空の値: False
  • Normalizes to: A Python True or False value.
  • Validates that the value is True (e.g. the check box is checked) if the field has required=True.
  • Error message keys: required

注釈

Since all Field subclasses have required=True by default, the validation condition here is important. If you want to include a boolean in your form that can be either True or False (e.g. a checked or unchecked checkbox), you must remember to pass in required=False when creating the BooleanField.

CharField

class CharField(**kwargs)[ソース]
  • デフォルトのウィジェット: TextInput
  • 空の値: empty_value として与えたもの
  • Normalizes to: A string.
  • Validates max_length or min_length, if they are provided. Otherwise, all inputs are valid.
  • Error message keys: required, max_length, min_length

Has three optional arguments for validation:

max_length
min_length

If provided, these arguments ensure that the string is at most or at least the given length.

strip

If True (default), the value will be stripped of leading and trailing whitespace.

empty_value
New in Django 1.11.

The value to use to represent "empty". Defaults to an empty string.

ChoiceField

class ChoiceField(**kwargs)[ソース]
  • デフォルトのウィジェット: Select
  • 空の値: '' (空の文字列)
  • Normalizes to: A string.
  • Validates that the given value exists in the list of choices.
  • Error message keys: required, invalid_choice

The invalid_choice error message may contain %(value)s, which will be replaced with the selected choice.

Takes one extra argument:

choices

Either an iterable (e.g., a list or tuple) of 2-tuples to use as choices for this field, or a callable that returns such an iterable. This argument accepts the same formats as the choices argument to a model field. See the model field reference documentation on choices for more details. If the argument is a callable, it is evaluated each time the field's form is initialized. Defaults to an empty list.

TypedChoiceField

class TypedChoiceField(**kwargs)[ソース]

Just like a ChoiceField, except TypedChoiceField takes two extra arguments, coerce and empty_value.

  • デフォルトのウィジェット: Select
  • 空の値: empty_value として与えたもの
  • Normalizes to: A value of the type provided by the coerce argument.
  • Validates that the given value exists in the list of choices and can be coerced.
  • Error message keys: required, invalid_choice

Takes extra arguments:

coerce

A function that takes one argument and returns a coerced value. Examples include the built-in int, float, bool and other types. Defaults to an identity function. Note that coercion happens after input validation, so it is possible to coerce to a value not present in choices.

empty_value

The value to use to represent "empty." Defaults to the empty string; None is another common choice here. Note that this value will not be coerced by the function given in the coerce argument, so choose it accordingly.

DateField

class DateField(**kwargs)[ソース]
  • デフォルトのウィジェット: DateInput
  • 空の値: None
  • Python の datetime.date オブジェクトに正規化されます。
  • 与えられた値が datetime.datedatetime.datetime または特定の日付の表示形式のどれかに当てはまるか検証します。
  • エラーメッセージのキー: requiredinvalid

1 つの省略可能な引数を取ります:

input_formats

文字列を有効な datetime.date オブジェクトに変換する試行に使う表示形式のリストです。

input_formats 引数が指定されなかった場合、デフォルトのインプット表示形式は以下の通りとなります:

['%Y-%m-%d',      # '2006-10-25'
 '%m/%d/%Y',      # '10/25/2006'
 '%m/%d/%y']      # '10/25/06'

加えて、設定内で USE_L10N=False を指定した場合、以下がデフォルトのインプット表示形式に含まれます:

['%b %d %Y',      # 'Oct 25 2006'
 '%b %d, %Y',     # 'Oct 25, 2006'
 '%d %b %Y',      # '25 Oct 2006'
 '%d %b, %Y',     # '25 Oct, 2006'
 '%B %d %Y',      # 'October 25 2006'
 '%B %d, %Y',     # 'October 25, 2006'
 '%d %B %Y',      # '25 October 2006'
 '%d %B, %Y']     # '25 October, 2006'

表示形式のローカル化 も参照してください。

DateTimeField

class DateTimeField(**kwargs)[ソース]
  • デフォルトのウィジェット: DateTimeInput
  • 空の値: None
  • Python の datetime.datetime オブジェクトに正規化されます。
  • 与えられた値が datetime.datetimedatetime.date または特定の日時の表示形式の文字列のどれかに当てはまるか検証します。
  • エラーメッセージのキー: requiredinvalid

1 つの省略可能な引数を取ります:

input_formats

有効な datetime.datetime オブジェクトに変換する試行に使う表示形式のリストです。

input_formats 引数が指定されなかった場合、デフォルトのインプット表示形式は以下の通りとなります:

['%Y-%m-%d %H:%M:%S',    # '2006-10-25 14:30:59'
 '%Y-%m-%d %H:%M',       # '2006-10-25 14:30'
 '%Y-%m-%d',             # '2006-10-25'
 '%m/%d/%Y %H:%M:%S',    # '10/25/2006 14:30:59'
 '%m/%d/%Y %H:%M',       # '10/25/2006 14:30'
 '%m/%d/%Y',             # '10/25/2006'
 '%m/%d/%y %H:%M:%S',    # '10/25/06 14:30:59'
 '%m/%d/%y %H:%M',       # '10/25/06 14:30'
 '%m/%d/%y']             # '10/25/06'

表示形式のローカル化 も参照してください。

DecimalField

class DecimalField(**kwargs)[ソース]
  • デフォルトのウィジェット: Field.localizeFalse のとき NumberInputTrue のとき TextInput.
  • 空の値: None
  • Python の decimal に正規化されます。
  • Validates that the given value is a decimal. Leading and trailing whitespace is ignored.
  • Error message keys: required, invalid, max_value, min_value, max_digits, max_decimal_places, max_whole_digits

The max_value and min_value error messages may contain %(limit_value)s, which will be substituted by the appropriate limit. Similarly, the max_digits, max_decimal_places and max_whole_digits error messages may contain %(max)s.

Takes four optional arguments:

max_value
min_value

These control the range of values permitted in the field, and should be given as decimal.Decimal values.

max_digits

The maximum number of digits (those before the decimal point plus those after the decimal point, with leading zeros stripped) permitted in the value.

decimal_places

The maximum number of decimal places permitted.

DurationField

class DurationField(**kwargs)[ソース]
  • デフォルトのウィジェット: TextInput
  • 空の値: None
  • Python の timedelta に正規化されます。
  • Validates that the given value is a string which can be converted into a timedelta.
  • Error message keys: required, invalid.

Accepts any format understood by parse_duration().

EmailField

class EmailField(**kwargs)[ソース]
  • デフォルトのウィジェット: EmailInput
  • 空の値: '' (空の文字列)
  • Normalizes to: A string.
  • Validates that the given value is a valid email address, using a moderately complex regular expression.
  • エラーメッセージのキー: requiredinvalid

Has two optional arguments for validation, max_length and min_length. If provided, these arguments ensure that the string is at most or at least the given length.

FileField

class FileField(**kwargs)[ソース]
  • デフォルトのウィジェット: ClearableFileInput
  • 空の値: None
  • ファイルコンテンツとファイル名を1つのオブジェクトにラッピングした UploadedFile オブジェクトに正規化されます。
  • Can validate that non-empty file data has been bound to the form.
  • Error message keys: required, invalid, missing, empty, max_length

Has two optional arguments for validation, max_length and allow_empty_file. If provided, these ensure that the file name is at most the given length, and that validation will succeed even if the file content is empty.

UploadedFile オブジェクトについて詳しく知るには、 ファイルのアップロードのドキュメント を読んでください。

フォーム内で FileField を使用する時は、ファイルのデータをフォームにバインディング することも必要です。

The max_length error refers to the length of the filename. In the error message for that key, %(max)d will be replaced with the maximum filename length and %(length)d will be replaced with the current filename length.

FilePathField

class FilePathField(**kwargs)[ソース]
  • デフォルトのウィジェット: Select
  • 空の値: None
  • Normalizes to: A string.
  • Validates that the selected choice exists in the list of choices.
  • Error message keys: required, invalid_choice

The field allows choosing from files inside a certain directory. It takes five extra arguments; only path is required:

path

The absolute path to the directory whose contents you want listed. This directory must exist.

recursive

If False (the default) only the direct contents of path will be offered as choices. If True, the directory will be descended into recursively and all descendants will be listed as choices.

match

A regular expression pattern; only files with names matching this expression will be allowed as choices.

allow_files

Optional. Either True or False. Default is True. Specifies whether files in the specified location should be included. Either this or allow_folders must be True.

allow_folders

Optional. Either True or False. Default is False. Specifies whether folders in the specified location should be included. Either this or allow_files must be True.

FloatField

class FloatField(**kwargs)[ソース]
  • デフォルトのウィジェット: Field.localizeFalse のとき NumberInputTrue のとき TextInput.
  • 空の値: None
  • Python の float に正規化されます。
  • Validates that the given value is a float. Leading and trailing whitespace is allowed, as in Python's float() function.
  • Error message keys: required, invalid, max_value, min_value

Takes two optional arguments for validation, max_value and min_value. These control the range of values permitted in the field.

ImageField

class ImageField(**kwargs)[ソース]
  • デフォルトのウィジェット: ClearableFileInput
  • 空の値: None
  • ファイルコンテンツとファイル名を1つのオブジェクトにラッピングした UploadedFile オブジェクトに正規化されます。
  • Validates that file data has been bound to the form, and that the file is of an image format understood by Pillow.
  • Error message keys: required, invalid, missing, empty, invalid_image

Using an ImageField requires that Pillow is installed with support for the image formats you use. If you encounter a corrupt image error when you upload an image, it usually means that Pillow doesn't understand its format. To fix this, install the appropriate library and reinstall Pillow.

When you use an ImageField on a form, you must also remember to bind the file data to the form.

After the field has been cleaned and validated, the UploadedFile object will have an additional image attribute containing the Pillow Image instance used to check if the file was a valid image. Also, UploadedFile.content_type will be updated with the image's content type if Pillow can determine it, otherwise it will be set to None.

IntegerField

class IntegerField(**kwargs)[ソース]
  • デフォルトのウィジェット: Field.localizeFalse のとき NumberInputTrue のとき TextInput.
  • 空の値: None
  • Normalizes to: A Python integer.
  • Validates that the given value is an integer. Leading and trailing whitespace is allowed, as in Python's int() function.
  • Error message keys: required, invalid, max_value, min_value

The max_value and min_value error messages may contain %(limit_value)s, which will be substituted by the appropriate limit.

Takes two optional arguments for validation:

max_value
min_value

These control the range of values permitted in the field.

GenericIPAddressField

class GenericIPAddressField(**kwargs)[ソース]

IPv4 または IPv6 アドレスのいずれかを持つフィールドです。

  • デフォルトのウィジェット: TextInput
  • 空の値: '' (空の文字列)
  • Normalizes to: A string. IPv6 addresses are normalized as described below.
  • 与えられた値が有効な IP アドレスを表しているか検証します。
  • エラーメッセージのキー: requiredinvalid

IPv6 アドレスは、 RFC 4291#section-2.2 section 2.2 (同セクションの paragraph 3 で提案された IPv4 のフォーマットの使用を含む) にしたがって、 ::ffff:192.0.2.0 のように正規化します。たとえば、 2001:0::0:012001::1 と正規化され、 ::ffff:0a0a:0a0a::ffff:10.10.10.10 と正規化されます。そして、すべての文字は小文字に変換されます。

次の2つの省略可能な引数を取ります:

protocol

有効な入力を指定したプロトコルに限定します。指定できる値は、 both (デフォルト)、 IPv4 または IPv6 です。大文字・小文字は無視されます。

unpack_ipv4

IPv4 にマッピングされた ::ffff:192.0.2.1 のようなアドレスをアンパックします。このオプションを有効にすると、このアドレスは 192.0.2.1 とアンパックされます。デフォルトは無効です。protocol'both' に設定されている場合にだけ使用できます。

MultipleChoiceField

class MultipleChoiceField(**kwargs)[ソース]
  • デフォルトのウィジェット: SelectMultiple
  • 空の値: [] (空のリスト)
  • Normalizes to: A list of strings.
  • Validates that every value in the given list of values exists in the list of choices.
  • Error message keys: required, invalid_choice, invalid_list

The invalid_choice error message may contain %(value)s, which will be replaced with the selected choice.

Takes one extra required argument, choices, as for ChoiceField.

TypedMultipleChoiceField

class TypedMultipleChoiceField(**kwargs)[ソース]

Just like a MultipleChoiceField, except TypedMultipleChoiceField takes two extra arguments, coerce and empty_value.

  • デフォルトのウィジェット: SelectMultiple
  • 空の値: empty_value として渡したもの
  • Normalizes to: A list of values of the type provided by the coerce argument.
  • Validates that the given values exists in the list of choices and can be coerced.
  • Error message keys: required, invalid_choice

The invalid_choice error message may contain %(value)s, which will be replaced with the selected choice.

Takes two extra arguments, coerce and empty_value, as for TypedChoiceField.

NullBooleanField

class NullBooleanField(**kwargs)[ソース]
  • デフォルトのウィジェット: NullBooleanSelect
  • 空の値: None
  • Normalizes to: A Python True, False or None value.
  • Validates nothing (i.e., it never raises a ValidationError).

RegexField

class RegexField(**kwargs)[ソース]
  • デフォルトのウィジェット: TextInput
  • 空の値: '' (空の文字列)
  • Normalizes to: A string.
  • Validates that the given value matches against a certain regular expression.
  • エラーメッセージのキー: requiredinvalid

Takes one required argument:

regex

A regular expression specified either as a string or a compiled regular expression object.

Also takes max_length, min_length, and strip, which work just as they do for CharField.

strip

Defaults to False. If enabled, stripping will be applied before the regex validation.

SlugField

class SlugField(**kwargs)[ソース]
  • デフォルトのウィジェット: TextInput
  • 空の値: '' (空の文字列)
  • Normalizes to: A string.
  • Validates that the given value contains only letters, numbers, underscores, and hyphens.
  • Error messages: required, invalid

This field is intended for use in representing a model SlugField in forms.

Takes an optional parameter:

allow_unicode

A boolean instructing the field to accept Unicode letters in addition to ASCII letters. Defaults to False.

TimeField

class TimeField(**kwargs)[ソース]
  • デフォルトのウィジェット: TextInput
  • 空の値: None
  • Python の datetime.time オブジェクトに正規化されます。
  • Validates that the given value is either a datetime.time or string formatted in a particular time format.
  • エラーメッセージのキー: requiredinvalid

1 つの省略可能な引数を取ります:

input_formats

A list of formats used to attempt to convert a string to a valid datetime.time object.

input_formats 引数が指定されなかった場合、デフォルトのインプット表示形式は以下の通りとなります:

'%H:%M:%S',     # '14:30:59'
'%H:%M',        # '14:30'

URLField

class URLField(**kwargs)[ソース]
  • デフォルトのウィジェット: URLInput
  • 空の値: '' (空の文字列)
  • Normalizes to: A string.
  • 与えられた値が有効な URL であることを検証します。
  • エラーメッセージのキー: requiredinvalid

以下の省略可能な引数を取ります。

max_length
min_length

These are the same as CharField.max_length and CharField.min_length.

UUIDField

class UUIDField(**kwargs)[ソース]
  • デフォルトのウィジェット: TextInput
  • 空の値: '' (空の文字列)
  • UUID オブジェクトに正規化されます。
  • エラーメッセージのキー: requiredinvalid

This field will accept any string format accepted as the hex argument to the UUID constructor.

Slightly complex built-in Field classes

ComboField

class ComboField(**kwargs)[ソース]
  • デフォルトのウィジェット: TextInput
  • 空の値: '' (空の文字列)
  • Normalizes to: A string.
  • Validates the given value against each of the fields specified as an argument to the ComboField.
  • エラーメッセージのキー: requiredinvalid

Takes one extra required argument:

fields

The list of fields that should be used to validate the field's value (in the order in which they are provided).

>>> from django.forms import ComboField
>>> f = ComboField(fields=[CharField(max_length=20), EmailField()])
>>> f.clean('test@example.com')
'test@example.com'
>>> f.clean('longemailaddress@example.com')
Traceback (most recent call last):
...
ValidationError: ['Ensure this value has at most 20 characters (it has 28).']

MultiValueField

class MultiValueField(fields=(), **kwargs)[ソース]
  • デフォルトのウィジェット: TextInput
  • 空の値: '' (空の文字列)
  • Normalizes to: the type returned by the compress method of the subclass.
  • Validates the given value against each of the fields specified as an argument to the MultiValueField.
  • Error message keys: required, invalid, incomplete

Aggregates the logic of multiple fields that together produce a single value.

This field is abstract and must be subclassed. In contrast with the single-value fields, subclasses of MultiValueField must not implement clean() but instead - implement compress().

Takes one extra required argument:

fields

A tuple of fields whose values are cleaned and subsequently combined into a single value. Each value of the field is cleaned by the corresponding field in fields -- the first value is cleaned by the first field, the second value is cleaned by the second field, etc. Once all fields are cleaned, the list of clean values is combined into a single value by compress().

Also takes some optional arguments:

require_all_fields

Defaults to True, in which case a required validation error will be raised if no value is supplied for any field.

When set to False, the Field.required attribute can be set to False for individual fields to make them optional. If no value is supplied for a required field, an incomplete validation error will be raised.

A default incomplete error message can be defined on the MultiValueField subclass, or different messages can be defined on each individual field. For example:

from django.core.validators import RegexValidator

class PhoneField(MultiValueField):
    def __init__(self, **kwargs):
        # Define one message for all fields.
        error_messages = {
            'incomplete': 'Enter a country calling code and a phone number.',
        }
        # Or define a different message for each field.
        fields = (
            CharField(
                error_messages={'incomplete': 'Enter a country calling code.'},
                validators=[
                    RegexValidator(r'^[0-9]+$', 'Enter a valid country calling code.'),
                ],
            ),
            CharField(
                error_messages={'incomplete': 'Enter a phone number.'},
                validators=[RegexValidator(r'^[0-9]+$', 'Enter a valid phone number.')],
            ),
            CharField(
                validators=[RegexValidator(r'^[0-9]+$', 'Enter a valid extension.')],
                required=False,
            ),
        )
        super().__init__(
            error_messages=error_messages, fields=fields,
            require_all_fields=False, **kwargs
        )
widget

Must be a subclass of django.forms.MultiWidget. Default value is TextInput, which probably is not very useful in this case.

compress(data_list)[ソース]

Takes a list of valid values and returns a "compressed" version of those values -- in a single value. For example, SplitDateTimeField is a subclass which combines a time field and a date field into a datetime object.

This method must be implemented in the subclasses.

SplitDateTimeField

class SplitDateTimeField(**kwargs)[ソース]
  • デフォルトのウィジェット: SplitDateTimeWidget
  • 空の値: None
  • Python の datetime.datetime オブジェクトに正規化されます。
  • Validates that the given value is a datetime.datetime or string formatted in a particular datetime format.
  • Error message keys: required, invalid, invalid_date, invalid_time

次の2つの省略可能な引数を取ります:

input_date_formats

文字列を有効な datetime.date オブジェクトに変換する試行に使う表示形式のリストです。

If no input_date_formats argument is provided, the default input formats for DateField are used.

input_time_formats

A list of formats used to attempt to convert a string to a valid datetime.time object.

If no input_time_formats argument is provided, the default input formats for TimeField are used.

Fields which handle relationships

Two fields are available for representing relationships between models: ModelChoiceField and 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.

For more complex uses, you can specify queryset=None when declaring the form field and then populate the queryset in the form's __init__() method:

class FooMultipleChoiceForm(forms.Form):
    foo_select = forms.ModelMultipleChoiceField(queryset=None)

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields['foo_select'].queryset = ...

ModelChoiceField

class ModelChoiceField(**kwargs)[ソース]
  • デフォルトのウィジェット: Select
  • 空の値: None
  • model インスタンスに正規化されます。
  • Validates that the given id exists in the queryset.
  • Error message keys: required, invalid_choice

Allows the selection of a single model object, suitable for representing a foreign key. Note that the default widget for ModelChoiceField becomes impractical when the number of entries increases. You should avoid using it for more than 100 items.

A single argument is required:

queryset

A QuerySet of model objects from which the choices for the field are derived and which is used to validate the user's selection. It's evaluated when the form is rendered.

ModelChoiceField also takes two optional arguments:

empty_label

By default the <select> widget used by ModelChoiceField will have an empty choice at the top of the list. You can change the text of this label (which is "---------" by default) with the empty_label attribute, or you can disable the empty label entirely by setting empty_label to None:

# A custom empty label
field1 = forms.ModelChoiceField(queryset=..., empty_label="(Nothing)")

# No empty label
field2 = forms.ModelChoiceField(queryset=..., empty_label=None)

Note that if a ModelChoiceField is required and has a default initial value, no empty choice is created (regardless of the value of empty_label).

to_field_name

This optional argument is used to specify the field to use as the value of the choices in the field's widget. Be sure it's a unique field for the model, otherwise the selected value could match more than one object. By default it is set to None, in which case the primary key of each object will be used. For example:

# No custom to_field_name
field1 = forms.ModelChoiceField(queryset=...)

would yield:

<select id="id_field1" name="field1">
<option value="obj1.pk">Object1</option>
<option value="obj2.pk">Object2</option>
...
</select>

and:

# to_field_name provided
field2 = forms.ModelChoiceField(queryset=..., to_field_name="name")

would yield:

<select id="id_field2" name="field2">
<option value="obj1.name">Object1</option>
<option value="obj2.name">Object2</option>
...
</select>

The __str__() 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:

from django.forms import ModelChoiceField

class MyModelChoiceField(ModelChoiceField):
    def label_from_instance(self, obj):
        return "My Object #%i" % obj.id

ModelMultipleChoiceField

class ModelMultipleChoiceField(**kwargs)[ソース]
  • デフォルトのウィジェット: SelectMultiple
  • 空の値: 空の QuerySet (self.queryset.none())
  • Normalizes to: A QuerySet of model instances.
  • Validates that every id in the given list of values exists in the queryset.
  • Error message keys: required, list, invalid_choice, invalid_pk_value

The invalid_choice message may contain %(value)s and the invalid_pk_value message may contain %(pk)s, which will be substituted by the appropriate values.

Allows the selection of one or more model objects, suitable for representing a many-to-many relation. As with ModelChoiceField, you can use label_from_instance to customize the object representations.

A single argument is required:

queryset

Same as ModelChoiceField.queryset.

1 つの省略可能な引数を取ります:

to_field_name

Same as ModelChoiceField.to_field_name.

Creating custom fields

If the built-in Field classes don't meet your needs, you can easily create custom Field classes. To do this, just create a subclass of django.forms.Field. Its only requirements are that it implement a clean() method and that its __init__() method accept the core arguments mentioned above (required, label, initial, widget, help_text).

You can also customize how a field will be accessed by overriding get_bound_field().

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