Django之Form组件

简介: Django之Form组件

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})


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