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Django之Form组件详解、图片上传及定制

wxchong 2024-07-22 22:42:58 开源技术 30 ℃ 0 评论

Django的Form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

Django form 流程

1、创建类，继承form.Form

2、页面根据类的对象自动创建html标签

3、提交，request.POST

封装到类的对象里，obj=UserInfo(request.POST)

4、用户输入是否合法

obj.is_valid()

5、全部合法，获取全部内容

obj.clean()

6、只有有不合法

obj.errors

1、创建Form类

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)
 )

2、View函数处理

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')

3、生成HTML

<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>


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

Form类

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;

1、Django内置字段如下：

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

 >>> 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')

2、Django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

# 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。

方式一：

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)
 # 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')

方式二：

使用django提供的ModelChoiceField和ModelMultipleChoiceField字段来实现

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

方式一：

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')], )

方式二：

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'}))

方法三：自定义方法

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

方式四：同时生成多个标签进行验证

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。

1、Form

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
 )

2、Views

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

3、HTML

<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>

基于form的django图片上传

第一种，直接上传

views

class TestimgForm(forms.Form):
 title = fields.CharField()
 img = fields.FileField()
def testimg(request):
 import os,time
 if request.method == 'GET':
 img = TestimgForm()
 return render(request, 'backend/testimg.html',{'img':img})
 else:
 obj = TestimgForm(request.POST, request.FILES)
	if obj.is_valid():
	 img = request.FILES.get('img')
 time = time.strftime('%Y%m%d%H%M%S')
 ext = os.path.splitext(img.name)[1]
	 file_path = os.path.join('upload/article',time+ext)
 #将图片重命名
 f = open(file_path,'wb')
 for line in imgs.chunks():
 f.write(line)
 f.close()
	 return HttpResponse('上传成功')

第二种，写入数据库

html

<!DOCTYPE html>
<html lang="en">
<head>
 <title>Title</title>
</head>
<body>
<form action="testimg" method="post" enctype="multipart/form-data">
 {% csrf_token %}
 {{ img }}
 <input type="submit" value="提交"/>
</form>
</body>
</html>

views

class TestimgForm(forms.Form):
 title = fields.CharField()
 img = fields.FileField()
def testimg(request):
 import os,time
 if request.method == 'GET':
 img = TestimgForm()
 return render(request, 'backend/testimg.html',{'img':img})
 else:
 obj = TestimgForm(request.POST, request.FILES)
		if obj.is_valid():
		title = obj.cleaned_data['title']
 img = obj.cleaned_data['img']
 time = time.strftime('%Y%m%d%H%M%S')
 ext = os.path.splitext(img.name)[1]
		img.name = time + ext
 Imgtest.objects.create(title=title,img=img)
		return HttpResponse('上传成功')

models.py

class Imgtest(models.Model):
 title = models.CharField(verbose_name='标题',max_length=32,)
 img = models.ImageField(verbose_name='缩略图',upload_to="./article/",
 help_text="大小200*200，不超过200k",
 default="/upload/article/common.jpg")

完整代码

class TestimgForm(forms.Form):
 title = fields.CharField()
 img = fields.FileField()
def testimg(request):
 import os,time
 if request.method == 'GET':
 img = TestimgForm()
 return render(request, 'backend/testimg.html',{'img':img})
 else:
 obj = TestimgForm(request.POST, request.FILES)
 if obj.is_valid():
 #(request.FILES['file'])
 # title = request.FILES.get('title')
 # img = request.FILES.get('img')
 title = obj.cleaned_data['title']
 img = obj.cleaned_data['img']
 time = time.strftime('%Y%m%d%H%M%S')
 ext = os.path.splitext(img.name)[1]
 img.name = time + ext
 # Imgtest.objects.create(title=title,img=img)
 # img是对象（文件大小，文件名称,文件内容。。。）
 # file_path = os.path.join('upload/article',time+ext)
 file_path = os.path.join('upload/article', img.name)
 f = open(file_path,'wb')
 for line in img.chunks():
 f.write(line)
 f.close()
 return HttpResponse('...')

Form定制化

定制错误信息

mail = forms.EmailField(error_messages={'required':u'邮箱不能为空'})

定制错误规则

mobile = forms.CharField(validators=[mobile_validate,],

error_messages={'required':u'手机不能为空'})

from django.shortcuts import render
from django import forms
import re
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 UserInfo(forms.Form):
 email = forms.EmailField(error_messages={'required':u'邮箱不能为空'})
 host = forms.CharField(error_messages={'required':u'主机不能为空'})
 port = forms.CharField(error_messages={'required':u'端口不能为空'})
 mobile = forms.CharField(validators=[mobile_validate,], #定义错误规则函数
 error_messages={'required':u'手机不能为空'},
 widget=forms.TextInput(attrs={'class':'form-control', #定义class
 'placeholder':u'请输入手机号'}))
 beizhu = forms.CharField(required=False, #备注允许为空
 widget=forms.Textarea(attrs={'class':'form-control', #定义为多行输入框
 'placeholder':u'请输入备注'}))
 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'}))

保存用户输入内容

obj = AccountForm.LoginForm(request.POST)

Form表单验证以及错误信息

错误信息格式：

普通格式：

from django.shortcuts import render,HttpResponse
from web.forms import account as AccountForm
 
def login(request):
 obj = AccountForm.LoginForm(request.POST)
 if request.method == 'POST':
 if obj.is_valid():
 all_data = obj.clean()
 else:
 #用于Form表单提交
 error = obj.errors
 #print error['username'][0]
 #print error['password'][0]
 return render(request, 'account/login.html',{'obj':obj,'error':error})
 
 return render(request, 'account/login.html',{'obj':obj})

创建一个simple_tag，使其输 error['username'][0]

{% load xx %}
<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title></title>
</head>
<body>
 <form action="/login/" method="post">
 <p>{{ obj.username }}
 {% error_msg error.username %}
 </p>
 <p>{{ obj.password }}
 {% error_msg error.password %}
 </p>
 <input type="submit" value="提交">
 </form>

JSON格式

def login(request):
 obj = AccountForm.LoginForm(request.POST)
 if request.method == 'POST':
 if obj.is_valid():
 all_data = obj.clean()
 else:
 #用于Ajax
error = obj.errors.as_json()
 #print error
return HttpResponse(error)
 return render(request, 'account/login.html',{'obj':obj,'error':error})
 return render(request, 'account/login.html',{'obj':obj})

Form生成select标签

静态select

动态select

当增加数据库数据时

不会更新，除非关闭程序，重新载入才会更新

解决方法：利用面向对象类的静态字段

from django import forms
import json
 
class ImportForm(forms.Form):
 #静态select
HOST_TYPE_LIST = (
 (0,'物理机'),
(1,'虚拟机'),
)
 host_type = forms.IntegerField(
 widget=forms.Select(choices=HOST_TYPE_LIST)
 )
 hostname = forms.CharField()
 
 #动态select
 # admin_dic = ((1,'yangmv'),(1,"bob"),)
 # w_obj = open('db_admin','w')
 # w_obj.write(json.dumps(admin_dic))
 # w_obj.close()
f_obj = open('db_admin','r')
 data = f_obj.read()
 data_tuple = json.loads(data)
 admin = forms.IntegerField(
 widget=forms.Select(choices=data_tuple)
 )
 
 def __init__(self,*args,**kwargs):
 super(ImportForm,self).__init__(*args,**kwargs)
 tmp = open('db_admin')
 data = tmp.read()
 data_tuple = json.loads(data)
 self.fields['admin'].widget.choices = data_tuple

再次增加数据库数据，直接刷新页面即可读取到新数据

优化后代码

from django import forms
import json
 
class ImportForm(forms.Form):
 admin = forms.IntegerField(widget=forms.Select())
 def __init__(self,*args,**kwargs):
 super(ImportForm,self).__init__(*args,**kwargs)
 tmp = open('db_admin')
 data = tmp.read()
 data_tuple = json.loads(data)
 self.fields['admin'].widget.choices = data_tuple

使用models获取select数据

class Select(models.Model):
 username = models.CharField(max_length=16)
 password = models.CharField(max_length=32)

<body>
 <form action="/home/">
 <p>{{ obj.admin }}</p>
 </form>
</body>

def home(request):
 obj = HomeForm.ImportForm()
 return render(request, 'home/home.html',{'obj':obj})

models.Select.objects.all().values_list('id','username')

https://www.cnblogs.com/yangmv/p/5327427.html

http://www.liujiangblog.com/course/django/152

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