Django框架Form

摘要

Django框架Form知识点

Django的Form主要具有一下几大功能:

  • 生成HTML标签
  • 验证用户数据(显示错误信息)
  • HTML Form提交保留上次提交数据
  • 初始化页面显示内容

创建Form类时,主要涉及到字段和插件,字段用于对用户请求数据的验证,插件用于自动生成HTML;

基本使用

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obj.is_valid
obj.errors
obj.cleaned_data

# form验证流程
is_valid 是否验证成功
errors 错误信息
full_clean 验证过程
_clean_fields:每个字段内置的正则验证 +(clean_字段名)钩子
_clean_form
clean
__all__ 整体的错误信息
_post_clean
cleaned_data 正确信息
errors 错误信息

创建Form类

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from django.forms import Form
from django.forms import widgets
from django.forms import fields

class MyForm(Form):
user = fields.CharField(
widget=widgets.TextInput(attrs={'id': 'i1', 'class': 'c1'})
)

gender = fields.ChoiceField(
choices=((1, '男'), (2, '女'),),
initial=2,
widget=widgets.RadioSelect
)

city = fields.CharField(
initial=2,
widget=widgets.Select(choices=((1,'上海'),(2,'北京'),))
)

pwd = fields.CharField(
widget=widgets.PasswordInput(attrs={'class': 'c1'}, render_value=True)
)

View函数处理

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from django.shortcuts import render, redirect
from .forms import MyForm


def index(request):
if request.method == "GET":
obj = MyForm()
return render(request, 'index.html', {'form': obj})
elif request.method == "POST":
obj = MyForm(request.POST, request.FILES)
if obj.is_valid():
values = obj.clean()
print(values)
else:
errors = obj.errors
print(errors)
return render(request, 'index.html', {'form': obj})
else:
return redirect('http://www.google.com')

生成HTML

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<form action="/" method="POST" enctype="multipart/form-data">
<p>{{ form.user }} {{ form.user.errors }}</p>
<p>{{ form.gender }} {{ form.gender.errors }}</p>
<p>{{ form.city }} {{ form.city.errors }}</p>
<p>{{ form.pwd }} {{ form.pwd.errors }}</p>
<input type="submit"/>
</form>

其他标签有

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<form method="POST" enctype="multipart/form-data">
{% csrf_token %}
{{ form.xxoo.label }}
{{ form.xxoo.id_for_label }}
{{ form.xxoo.label_tag }}
{{ form.xxoo.errors }}
{{ form.as_p }}
{{ form.as_ul }}
{{ form.as_table }}
<p>{{ form.user }} {{ form.user.errors }}</p>
<input type="submit" />
</form>

内置字段

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Field
required=True, 是否允许为空
widget=None, HTML插件
label=None, 用于生成Label标签或显示内容
initial=None, 初始值
help_text='', 帮助信息(在标签旁边显示)
error_messages=None, 错误信息 {'required': '不能为空', 'invalid': '格式错误'}
show_hidden_initial=False, 是否在当前插件后面再加一个隐藏的且具有默认值的插件(可用于检验两次输入是否一直)
validators=[], 自定义验证规则
localize=False, 是否支持本地化
disabled=False, 是否可以编辑
label_suffix=None Label内容后缀


CharField(Field)
max_length=None, 最大长度
min_length=None, 最小长度
strip=True 是否移除用户输入空白

IntegerField(Field)
max_value=None, 最大值
min_value=None, 最小值

FloatField(IntegerField)
...

DecimalField(IntegerField)
max_value=None, 最大值
min_value=None, 最小值
max_digits=None, 总长度
decimal_places=None, 小数位长度

BaseTemporalField(Field)
input_formats=None 时间格式化

DateField(BaseTemporalField) 格式:2015-09-01
TimeField(BaseTemporalField) 格式:11:12
DateTimeField(BaseTemporalField)格式:2015-09-01 11:12

DurationField(Field) 时间间隔:%d %H:%M:%S.%f
...

RegexField(CharField)
regex, 自定制正则表达式
max_length=None, 最大长度
min_length=None, 最小长度
error_message=None, 忽略,错误信息使用 error_messages={'invalid': '...'}

EmailField(CharField)
...

FileField(Field)
allow_empty_file=False 是否允许空文件

ImageField(FileField)
...
注:需要PIL模块,pip3 install Pillow
以上两个字典使用时,需要注意两点:
- form表单中 enctype="multipart/form-data"
- view函数中 obj = MyForm(request.POST, request.FILES)

URLField(Field)
...


BooleanField(Field)
...

NullBooleanField(BooleanField)
...

ChoiceField(Field)
...
choices=(), 选项,如:choices = ((0,'上海'),(1,'北京'),)
required=True, 是否必填
widget=None, 插件,默认select插件
label=None, Label内容
initial=None, 初始值
help_text='', 帮助提示


ModelChoiceField(ChoiceField)
... django.forms.models.ModelChoiceField
queryset, # 查询数据库中的数据
empty_label="---------", # 默认空显示内容
to_field_name=None, # HTML中value的值对应的字段
limit_choices_to=None # ModelForm中对queryset二次筛选

ModelMultipleChoiceField(ModelChoiceField)
... django.forms.models.ModelMultipleChoiceField



TypedChoiceField(ChoiceField)
coerce = lambda val: val 对选中的值进行一次转换
empty_value= '' 空值的默认值

MultipleChoiceField(ChoiceField)
...

TypedMultipleChoiceField(MultipleChoiceField)
coerce = lambda val: val 对选中的每一个值进行一次转换
empty_value= '' 空值的默认值

ComboField(Field)
fields=() 使用多个验证,如下:即验证最大长度20,又验证邮箱格式
fields.ComboField(fields=[fields.CharField(max_length=20), fields.EmailField(),])

MultiValueField(Field)
PS: 抽象类,子类中可以实现聚合多个字典去匹配一个值,要配合MultiWidget使用

SplitDateTimeField(MultiValueField)
input_date_formats=None, 格式列表:['%Y--%m--%d', '%m%d/%Y', '%m/%d/%y']
input_time_formats=None 格式列表:['%H:%M:%S', '%H:%M:%S.%f', '%H:%M']

FilePathField(ChoiceField) 文件选项,目录下文件显示在页面中
path, 文件夹路径
match=None, 正则匹配
recursive=False, 递归下面的文件夹
allow_files=True, 允许文件
allow_folders=False, 允许文件夹
required=True,
widget=None,
label=None,
initial=None,
help_text=''

GenericIPAddressField
protocol='both', both,ipv4,ipv6支持的IP格式
unpack_ipv4=False 解析ipv4地址,如果是::ffff:192.0.2.1时候,可解析为192.0.2.1, PS:protocol必须为both才能启用

SlugField(CharField) 数字,字母,下划线,减号(连字符)
...

UUIDField(CharField) uuid类型
...

注:UUID是根据MAC以及当前时间等创建的不重复的随机字符串

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>>> import uuid

# make a UUID based on the host ID and current time
>>> uuid.uuid1() # doctest: +SKIP
UUID('a8098c1a-f86e-11da-bd1a-00112444be1e')

# make a UUID using an MD5 hash of a namespace UUID and a name
>>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org')
UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e')

# make a random UUID
>>> uuid.uuid4() # doctest: +SKIP
UUID('16fd2706-8baf-433b-82eb-8c7fada847da')

# make a UUID using a SHA-1 hash of a namespace UUID and a name
>>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org')
UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d')

# make a UUID from a string of hex digits (braces and hyphens ignored)
>>> x = uuid.UUID('{00010203-0405-0607-0809-0a0b0c0d0e0f}')

# convert a UUID to a string of hex digits in standard form
>>> str(x)
'00010203-0405-0607-0809-0a0b0c0d0e0f'

# get the raw 16 bytes of the UUID
>>> x.bytes
b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f'

# make a UUID from a 16-byte string
>>> uuid.UUID(bytes=x.bytes)
UUID('00010203-0405-0607-0809-0a0b0c0d0e0f')

内置插件

  • TextInput(Input)
  • NumberInput(TextInput)
  • EmailInput(TextInput)
  • URLInput(TextInput)
  • PasswordInput(TextInput)
  • HiddenInput(TextInput)
  • Textarea(Widget)
  • DateInput(DateTimeBaseInput)
  • DateTimeInput(DateTimeBaseInput)
  • TimeInput(DateTimeBaseInput)
  • CheckboxInput
  • Select
  • NullBooleanSelect
  • SelectMultiple
  • RadioSelect
  • CheckboxSelectMultiple
  • FileInput
  • ClearableFileInput
  • MultipleHiddenInput
  • SplitDateTimeWidget
  • SplitHiddenDateTimeWidget
  • SelectDateWidget*

常用选择插件

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# 单radio,值为字符串
# user = fields.CharField(
# initial=2,
# widget=widgets.RadioSelect(choices=((1,'上海'),(2,'北京'),))
# )

# 单radio,值为字符串
# user = fields.ChoiceField(
# choices=((1, '上海'), (2, '北京'),),
# initial=2,
# widget=widgets.RadioSelect
# )

# 单select,值为字符串
# user = fields.CharField(
# initial=2,
# widget=widgets.Select(choices=((1,'上海'),(2,'北京'),))
# )

# 单select,值为字符串
# user = fields.ChoiceField(
# choices=((1, '上海'), (2, '北京'),),
# initial=2,
# widget=widgets.Select
# )

# 多选select,值为列表
# user = fields.MultipleChoiceField(
# choices=((1,'上海'),(2,'北京'),),
# initial=[1,],
# widget=widgets.SelectMultiple
# )


# 单checkbox
# user = fields.CharField(
# widget=widgets.CheckboxInput()
# )


# 多选checkbox,值为列表
# user = fields.MultipleChoiceField(
# initial=[2, ],
# choices=((1, '上海'), (2, '北京'),),
# widget=widgets.CheckboxSelectMultiple
# )

在使用选择标签时,需要注意choices的选项可以从数据库中获取,但是由于是静态字段 获取的值无法实时更新,那么需要自定义构造方法从而达到此目的。

方法一

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from django.forms import Form
from django.forms import widgets
from django.forms import fields
from django.core.validators import RegexValidator

class MyForm(Form):

user = fields.ChoiceField(
# choices=((1, '上海'), (2, '北京'),),
initial=2,
widget=widgets.Select
)

def __init__(self, *args, **kwargs):
super(MyForm,self).__init__(*args, **kwargs)
# 字段自动更新
# self.fields['user'].widget.choices = ((1, '上海'), (2, '北京'),)
# 或
self.fields['user'].widget.choices = models.Classes.objects.all().value_list('id','caption')

方法二

使用django提供的ModelChoiceField和ModelMultipleChoiceField字段来实现

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from django import forms
from django.forms import fields
from django.forms import widgets
from django.forms import models as form_model
from django.core.exceptions import ValidationError
from django.core.validators import RegexValidator

class FInfo(forms.Form):
authors = form_model.ModelMultipleChoiceField(queryset=models.NNewType.objects.all())
# authors = form_model.ModelChoiceField(queryset=models.NNewType.objects.all())

自定义验证规则

方法一

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from django.forms import Form
from django.forms import widgets
from django.forms import fields
from django.core.validators import RegexValidator

class MyForm(Form):
user = fields.CharField(
validators=[RegexValidator(r'^[0-9]+$', '请输入数字'), RegexValidator(r'^159[0-9]+$', '数字必须以159开头')],
)

方法二

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import re
from django.forms import Form
from django.forms import widgets
from django.forms import fields
from django.core.exceptions import ValidationError


# 自定义验证规则
def mobile_validate(value):
mobile_re = re.compile(r'^(13[0-9]|15[012356789]|17[678]|18[0-9]|14[57])[0-9]{8}$')
if not mobile_re.match(value):
raise ValidationError('手机号码格式错误')


class PublishForm(Form):


title = fields.CharField(max_length=20,
min_length=5,
error_messages={'required': '标题不能为空',
'min_length': '标题最少为5个字符',
'max_length': '标题最多为20个字符'},
widget=widgets.TextInput(attrs={'class': "form-control",
'placeholder': '标题5-20个字符'}))


# 使用自定义验证规则
phone = fields.CharField(validators=[mobile_validate, ],
error_messages={'required': '手机不能为空'},
widget=widgets.TextInput(attrs={'class': "form-control",
'placeholder': u'手机号码'}))

email = fields.EmailField(required=False,
error_messages={'required': u'邮箱不能为空','invalid': u'邮箱格式错误'},
widget=widgets.TextInput(attrs={'class': "form-control", 'placeholder': u'邮箱'}))

自定义方法

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from django import forms
from django.forms import fields
from django.forms import widgets
from django.core.exceptions import ValidationError
from django.core.validators import RegexValidator

class FInfo(forms.Form):
username = fields.CharField(max_length=5,
validators=[RegexValidator(r'^[0-9]+$', 'Enter a valid extension.', 'invalid')], )
email = fields.EmailField()

def clean_username(self):
"""
Form中字段中定义的格式匹配完之后,执行此方法进行验证
:return:
"""
value = self.cleaned_data['username']
if "666" in value:
raise ValidationError('666已经被玩烂了...', 'invalid')
return value

同时生成多个标签进行验证

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from django.forms import Form
from django.forms import widgets
from django.forms import fields

from django.core.validators import RegexValidator


############## 自定义字段 ##############
class PhoneField(fields.MultiValueField):
def __init__(self, *args, **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.
f = (
fields.CharField(
error_messages={'incomplete': 'Enter a country calling code.'},
validators=[
RegexValidator(r'^[0-9]+$', 'Enter a valid country calling code.'),
],
),
fields.CharField(
error_messages={'incomplete': 'Enter a phone number.'},
validators=[RegexValidator(r'^[0-9]+$', 'Enter a valid phone number.')],
),
fields.CharField(
validators=[RegexValidator(r'^[0-9]+$', 'Enter a valid extension.')],
required=False,
),
)
super(PhoneField, self).__init__(error_messages=error_messages, fields=f, require_all_fields=False, *args,
**kwargs)

def compress(self, data_list):
"""
当用户验证都通过后,该值返回给用户
:param data_list:
:return:
"""
return data_list

############## 自定义插件 ##############
class SplitPhoneWidget(widgets.MultiWidget):
def __init__(self):
ws = (
widgets.TextInput(),
widgets.TextInput(),
widgets.TextInput(),
)
super(SplitPhoneWidget, self).__init__(ws)

def decompress(self, value):
"""
处理初始值,当初始值initial不是列表时,调用该方法
:param value:
:return:
"""
if value:
return value.split(',')
return [None, None, None]

初始化数据

在Web应用程序中开发编写功能时,时常用到获取数据库中的数据并将值初始化在HTML中的标签上。

Form

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from django.forms import Form
from django.forms import widgets
from django.forms import fields
from django.core.validators import RegexValidator


class MyForm(Form):
user = fields.CharField()

city = fields.ChoiceField(
choices=((1, '上海'), (2, '北京'),),
widget=widgets.Select
)

Views

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from django.shortcuts import render, redirect
from .forms import MyForm


def index(request):
if request.method == "GET":
values = {'user': 'root', 'city': 2}
obj = MyForm(values)
obj = MyForm(initial = values)

return render(request, 'index.html', {'form': obj})
elif request.method == "POST":
return redirect('http://www.google.com')
else:
return redirect('http://www.google.com')

Html

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<form method="POST" enctype="multipart/form-data">
{% csrf_token %}
<p>{{ form.user }} {{ form.user.errors }}</p>
<p>{{ form.city }} {{ form.city.errors }}</p>

<input type="submit"/>
</form>

用户验证Form

Form

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#!/usr/bin/env python
# -*- coding:utf-8 -*-
import re
from django import forms
from django.core.exceptions import ValidationError


def mobile_validate(value):
mobile_re = re.compile(r'^(13[0-9]|15[012356789]|17[678]|18[0-9]|14[57])[0-9]{8}$')
if not mobile_re.match(value):
raise ValidationError('手机号码格式错误')


class PublishForm(forms.Form):

user_type_choice = (
(0, u'普通用户'),
(1, u'高级用户'),
)

user_type = forms.IntegerField(widget=forms.widgets.Select(choices=user_type_choice,
attrs={'class': "form-control"}))

title = forms.CharField(max_length=20,
min_length=5,
error_messages={'required': u'标题不能为空',
'min_length': u'标题最少为5个字符',
'max_length': u'标题最多为20个字符'},
widget=forms.TextInput(attrs={'class': "form-control",
'placeholder': u'标题5-20个字符'}))

memo = forms.CharField(required=False,
max_length=256,
widget=forms.widgets.Textarea(attrs={'class': "form-control no-radius", 'placeholder': u'详细描述', 'rows': 3}))

phone = forms.CharField(validators=[mobile_validate, ],
error_messages={'required': u'手机不能为空'},
widget=forms.TextInput(attrs={'class': "form-control",
'placeholder': u'手机号码'}))

email = forms.EmailField(required=False,
error_messages={'required': u'邮箱不能为空','invalid': u'邮箱格式错误'},
widget=forms.TextInput(attrs={'class': "form-control", 'placeholder': u'邮箱'}))

View

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def publish(request):
ret = {'status': False, 'data': '', 'error': '', 'summary': ''}
if request.method == 'POST':
request_form = PublishForm(request.POST)
if request_form.is_valid():
request_dict = request_form.clean()
print request_dict
ret['status'] = True
else:
error_msg = request_form.errors.as_json()
ret['error'] = json.loads(error_msg)
return HttpResponse(json.dumps(ret))

ModelForm组件

在使用Model和Form时,都需要对字段进行定义并指定类型,通过ModelForm则可以省去From中字段的定义

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class AdminModelForm(forms.ModelForm):

class Meta:
model = models.Admin
#fields = '__all__'
fields = ('username', 'email')

widgets = {
'email' : forms.PasswordInput(attrs={'class':"alex"}),
}

详细参数

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a.  class Meta:
model, # 对应Model的
fields=None, # 字段
exclude=None, # 排除字段
labels=None, # 提示信息
help_texts=None, # 帮助提示信息
widgets=None, # 自定义插件
error_messages=None, # 自定义错误信息(整体错误信息from django.core.exceptions import NON_FIELD_ERRORS)
field_classes=None # 自定义字段类 (也可以自定义字段)
localized_fields=('birth_date',) # 本地化,如:根据不同时区显示数据
如:
数据库中
2016-12-27 04:10:57
setting中的配置
TIME_ZONE = 'Asia/Shanghai'
USE_TZ = True
则显示:
2016-12-27 12:10:57
b. 验证执行过程
is_valid -> full_clean -> 钩子 -> 整体错误

c. 字典字段验证
def clean_字段名(self):
# 可以抛出异常
# from django.core.exceptions import ValidationError
return "新值"
d. 用于验证
model_form_obj = XXOOModelForm()
model_form_obj.is_valid()
model_form_obj.errors.as_json()
model_form_obj.clean()
model_form_obj.cleaned_data
e. 用于创建
model_form_obj = XXOOModelForm(request.POST)
#### 页面显示,并提交 #####
# 默认保存多对多
obj = form.save(commit=True)
# 不做任何操作,内部定义 save_m2m(用于保存多对多)
obj = form.save(commit=False)
obj.save() # 保存单表信息
model_form_obj.save_m2m() # 保存关联多对多信息

f. 用于更新和初始化
obj = model.tb.objects.get(id=1)
# 初始化数据
model_form_obj = XXOOModelForm(instance=obj)
# 更新已有数据
model_form_obj = XXOOModelForm(request.POST,instance=obj)
...

PS: 单纯初始化
model_form_obj = XXOOModelForm(initial={...})