首页 > 技术文章 > Form组件

wdyjx 2019-10-28 22:47 原文

1.Form介绍

我们之前在HTML页面中利用form表单向后端提交数据时,都会写一些获取用户输入的标签并且用form标签把它们包起来。

  与此同时我们在好多场景下都需要对用户的输入做校验,比如校验用户是否输入,输入的长度和格式等正不正确。如果用户输入的内容有错误就需要在页面上相应的位置显示对应的错误信息.。

  Django form组件就实现了上面所述的功能。

  总结一下,其实form组件的主要功能如下:

    生成页面可用的HTML标签

    对用户提交的数据进行校验

    保留上次输入内容

2. Form常用字段与插件

  

  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;

initial

    初始值,input框里面的初始值。

class LoginForm(forms.Form):
    username = forms.CharField(  
        min_length=8,
        label="用户名",
        initial="张三"  # 设置默认值
    )
    pwd = forms.CharField(min_length=6, label="密码")

error_messages

    重写错误信息。

class LoginForm(forms.Form):
    username = forms.CharField(
        min_length=8,
        label="用户名",
        initial="张三",
        error_messages={
            "required": "不能为空",
            "invalid": "格式错误",
            "min_length": "用户名最短8位"
        }
    )
    pwd = forms.CharField(min_length=6, label="密码")

password

class LoginForm(forms.Form):
    ...
    pwd = forms.CharField(
        min_length=6,
        label="密码",
        widget=forms.widgets.PasswordInput(attrs={'class': 'c1'}, render_value=True) #这个密码字段和其他字段不一样,默认在前端输入数据错误的时候,点击提交之后,默认是不保存的原来数据的,但是可以通过这个render_value=True让这个字段在前端保留用户输入的数据
    )

radioSelect

    单radio值为字符串

class LoginForm(forms.Form):
    username = forms.CharField(  #其他选择框或者输入框,基本都是在这个CharField的基础上通过插件来搞的
        min_length=8,
        label="用户名",
        initial="张三",
        error_messages={
            "required": "不能为空",
            "invalid": "格式错误",
            "min_length": "用户名最短8位"
        }
    )
    pwd = forms.CharField(min_length=6, label="密码")
    gender = forms.fields.ChoiceField(
        choices=((1, "男"), (2, "女"), (3, "保密")),
        label="性别",
        initial=3,
        widget=forms.widgets.RadioSelect()
    )

单选Select

class LoginForm(forms.Form):
    ...
    hobby = forms.fields.ChoiceField(  #注意,单选框用的是ChoiceField,并且里面的插件是Select,不然验证的时候会报错, Select a valid choice的错误。
        choices=((1, "篮球"), (2, "足球"), (3, "双色球"), ),
        label="爱好",
        initial=3,
        widget=forms.widgets.Select()
    )

多选Select

class LoginForm(forms.Form):
    ...
    hobby = forms.fields.MultipleChoiceField( #多选框的时候用MultipleChoiceField,并且里面的插件用的是SelectMultiple,不然验证的时候会报错。
        choices=((1, "篮球"), (2, "足球"), (3, "双色球"), ),
        label="爱好",
        initial=[1, 3],
        widget=forms.widgets.SelectMultiple()
    )

单选checkbox

class LoginForm(forms.Form):
    ...
    keep = forms.fields.ChoiceField(
        label="是否记住密码",
        initial="checked",
        widget=forms.widgets.CheckboxInput()
    )

  单选checkbox示例:

#单选的checkbox
    class TestForm2(forms.Form):
        keep = forms.ChoiceField(
            choices=(
                ('True',1),
                ('False',0),
            ),

            label="是否7天内自动登录",
            initial="1",
            widget=forms.widgets.CheckboxInput(), 
        )
    选中:'True'   #form只是帮我们做校验,校验选择内容的时候,就是看在没在我们的choices里面,里面有这个值,表示合法,没有就不合法
    没选中:'False'
    ---保存到数据库里面  keep:'True'
    if keep == 'True':
        session 设置有效期7天
    else:
        pass

多选checkbox

class LoginForm(forms.Form):
    ...
    hobby = forms.fields.MultipleChoiceField(
        choices=((1, "篮球"), (2, "足球"), (3, "双色球"),),
        label="爱好",
        initial=[1, 3],
        widget=forms.widgets.CheckboxSelectMultiple()
    )

date类型

from django import forms
from django.forms import widgets
class BookForm(forms.Form):
    date = forms.DateField(widget=widgets.TextInput(attrs={'type':'date'}))  #必须指定type,不然不能渲染成选择时间的input框

choice字段注意事项

    在使用选择标签时,需要注意choices的选项可以配置从数据库中获取,但是由于是静态字段 获取的值无法实时更新,需要重写构造方法从而实现choice实时更新。

    方式一:

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

 
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) #注意重写init方法的时候,*args和**kwargs一定要给人家写上,不然会出问题,并且验证总是不能通过,还不显示报错信息
        # self.fields['user'].choices = ((1, '上海'), (2, '北京'),)
        # 或
        self.fields['user'].choices = models.Classes.objects.all().values_list('id','caption')

    方式二:

from django import forms
from django.forms import fields
from django.forms import models as form_model

 
class FInfo(forms.Form):  
    authors = forms.ModelMultipleChoiceField(queryset=models.NNewType.objects.all())  # 多选    #或者下面这种方式,通过forms里面的models中提供的方法也是一样的。
    authors = form_model.ModelMultipleChoiceField(queryset=models.NNewType.objects.all())  # 多选
    #authors = form_model.ModelChoiceField(queryset=models.NNewType.objects.all())  # 单选    #或者,forms.ModelChoiceField(queryset=models.Publisth.objects.all(),widget=forms.widgets.Select()) 单选    #
   authors = forms.ModelMultipleChoiceField(    queryset=models.Author.objects.all(),    widget = forms.widgets.Select(attrs={'class': 'form-control'}   ))
   #如果用这种方式,别忘了model表中,NNEWType的__str__方法要写上,不然选择框里面是一个个的object对象

3.Form所有内置字段

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'}
    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
复制代码

内置字段

4.form组件使用

urls

path('',views.index),

views

from django.shortcuts import render

# Create your views here.

from   django import    forms
class  UserInfo(forms.Form):
    username = forms.CharField(
        label="用户名"

    )
    password = forms.CharField(
        label="密码",
        widget=forms.PasswordInput(attrs={'class':'c1'}), #加密文
        #attrs 添加标签属性

    )

    sex =forms.ChoiceField(
        choices = ((1,"男"),(2,"女"),),#单选下拉框
        # widget=forms.RadioSelect #改样式
    )

    hobby =forms.MultipleChoiceField( #多选下拉框
        choices=((1,"抽烟"),(2,'喝酒'),(3,"游戏")),
        widget=forms.CheckboxSelectMultiple,#改样式
    )
    me = forms.ChoiceField(
        label="记住我",     #记住登陆状态
        widget=forms.CheckboxInput
    )
    bday = forms.DateField(
        label="日期",
        widget=forms.DateInput(attrs={'type':"date"}) #日期加样式
    )


def index(request):
    u_obj = UserInfo()

    return render(request,"index.html",{'u_obj':u_obj})

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .c1{
            background-color: yellow;
        }
    </style>
</head>

<body>
<form action="" method="post">
    {% csrf_token %}
    <div>
        {{ u_obj.username.label }} {{ u_obj.username }}
    </div>
    <div>
        {{ u_obj.password.label }} {{ u_obj.password }}
    </div>
    <div>
        {{ u_obj.sex }}
    </div>
    <div>
        {{ u_obj.hobby }}
    </div>
    <div>
        {{ u_obj.me  }}{{ u_obj.me.label }}
    </div>
    <div>
        {{ u_obj.bday }}
    </div>

    <input type="submit">

</form>

</body>

</html>

5.简单校验

views

from django.shortcuts import render,HttpResponse

# Create your views here.

from   django import    forms
class  UserInfo(forms.Form):
    username = forms.CharField(
        label="用户名", #默认输入
        # initial='zbb',
        # required=True,#默认不能为空
        min_length=6,
        error_messages={
            'required':"不能为空",
            "min_length":"太短了",
        }

    )
    password = forms.CharField(
        label="密码",
        widget=forms.PasswordInput()
    )




def index(request):
    if request.method == "GET":
        u_obj = UserInfo()

        return render(request,"index.html",{'u_obj':u_obj})
    else:
        u_obj = UserInfo(request.POST)

        #u_obj.is_valid() #验证用户输入的数据,全部正确返回ture,反之返回False
        if  u_obj.is_valid():
            print('正确',u_obj.cleaned_data)#成功的数据
            return HttpResponse('ok')
        else:
            print('错误',u_obj.errors) #失败的数据

            return render(request, "index.html", {'u_obj': u_obj})

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

</head>


<body>
<form action="" method="post" novalidate>
{#    禁止浏览器检查#}
    {% csrf_token %}
    <div>
        {{ u_obj.username.label }} {{ u_obj.username }}{{ u_obj.username.errors.0 }}
    </div>
    <div>
        {{ u_obj.password.label }} {{ u_obj.password }}{{ u_obj.password.errors.0 }}
    </div>
    <input type="submit">

</form>

</body>

</html>

6.字段效验

RegexValidator验证器

更改上上面的views

class  UserInfo(forms.Form):
    username = forms.CharField(
        label="用户名", #默认输入
        # initial='zbb',
        # required=True,#默认不能为空
        min_length=6,
        error_messages={
            'required':"不能为空",
            "min_length":"太短了",
        },
        validators = [
            RegexValidator(r'^[0-9]+$', '请输入数字'),
            #可以写多个
        ]

    )
    password = forms.CharField(
        label="密码",
        widget=forms.PasswordInput()
    )

7.自定义校验

from django.shortcuts import render,HttpResponse
from   django import    forms
from django.core.exceptions import ValidationError
import re


# 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')  # 自定义验证规则的时候,如果不符合你的规则,需要自己发起错误


class  UserInfo(forms.Form):
    username = forms.CharField(
        label="用户名", #默认输入
        # initial='zbb',
        # required=True,#默认不能为空
        min_length=6,
        error_messages={
            'required':"不能为空",
            "min_length":"太短了",
        },
        validators = [mobile_validate]

    )
    password = forms.CharField(
        label="密码",
        widget=forms.PasswordInput()
    )


8.Hook钩子

除了上面两种方式,我们还可以在Form类中定义钩子函数,来实现自定义的验证功能

9.局部钩子

我们在Fom类中定义 clean_字段名() 方法,就能够实现对特定字段进行校验。

from django.shortcuts import render,HttpResponse
from   django import    forms
from django.core.exceptions import ValidationError
import re


# 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')  # 自定义验证规则的时候,如果不符合你的规则,需要自己发起错误


class  UserInfo(forms.Form):
    username = forms.CharField(
        label="用户名", #默认输入
        # initial='zbb',
        # required=True,#默认不能为空
        min_length=6,
        error_messages={
            'required':"不能为空",
            "min_length":"太短了",
        },
        validators = [mobile_validate]

    )
    password = forms.CharField(
        label="密码",
        widget=forms.PasswordInput()
    )
#局部钩子
    def clean_username(self):
        value = self.cleaned_data.get('username')
        if "666" in value:
            raise ValidationError("666不行")
        else:
            return value

10.全局钩子

我们在Fom类中定义 clean() 方法,就能够实现对字段进行全局校验,字段全部验证完,局部钩子也全部执行完之后,执行这个全局钩子校验

views

from django.shortcuts import render,redirect,HttpResponse

from django import forms

from django.core.exceptions import ValidationError



class UserInfo(forms.Form):

    username=forms.CharField(
        label='用户名:',

    )

    password=forms.CharField(
        label='密码:',
        widget=forms.widgets.PasswordInput(attrs={'class':'c1'},render_value=True),

    )

    r_password = forms.CharField(
        label='确认密码:',
        widget=forms.widgets.PasswordInput(attrs={'class': 'c1'}, render_value=True),

    )

    # 局部钩子
    def clean_username(self):
        value = self.cleaned_data.get('username')
        if '666' in value:
            raise ValidationError('光喊666是不行的!')
        else:
            return value

    # 全局钩子
    def clean(self):
        password = self.cleaned_data.get('password')
        r_password = self.cleaned_data.get('r_password')

        if password == r_password:
            return self.cleaned_data
        else:
            # raise ValidationError('两次密码不一致!!!!')  #传到的是全局
            self.add_error('r_password','两次密码不一致~~~~') # 给单独的某个字段加错误信息



def index(request):

    if request.method == 'GET':
        u_obj = UserInfo()


        return render(request,'index.html',{'u_obj':u_obj})

    else:

        u_obj = UserInfo(request.POST)  #{'username':'','password':'123'}
        print(u_obj.fields)
        # u_obj.is_valid()  #校验用户提交的数据,全部校验成功返回True,任意一个失败都返回False
        if u_obj.is_valid():
            # {'username': 'a范德萨水电费', 'password': '1111'}
            print('正确数据',u_obj.cleaned_data)  #校验成功之后的数据cleaned_data

            return HttpResponse('ok')
        else:
            # print('错误信息',u_obj.errors)

            return render(request,'index.html',{'u_obj':u_obj})



html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

</head>


<body>
<form action="" method="post" novalidate>
{#    禁止浏览器检查#}
    {% csrf_token %}
    <div>
        {{ u_obj.username.label }} {{ u_obj.username }}{{ u_obj.username.errors.0 }}
    </div>
    <div>
        {{ u_obj.password.label }} {{ u_obj.password }}{{ u_obj.password.errors.0 }}
    </div>
    <div>
        {{ u_obj.r_password.label }} {{ u_obj.r_password }}{{ u_obj.r_password.errors.0 }}
    </div>
    <input type="submit">

</form>

</body>

</html>

11.进阶

from组件生成页面

简单的处理方法

看思路

class AddBookForm(forms.Form):
    title = forms.CharField(
        label="书名",
        # widget = forms.TextInput(attrs={'class': 'form-control'}),
    )
    price = forms.DecimalField(
        label="价格",
        max_digits=6,
        decimal_places=2,
        # widget=forms.TextInput(attrs={'class': 'form-control'}),
    )

    publishDate = forms.CharField(
        label="出版日期",
        # widget=forms.TextInput(attrs={'type':'date','class': 'form-control'})
    )
    publish = forms.ChoiceField(
        choices=models.Publish.objects.all().values_list('nid','name'),
        # widget=forms.Select(attrs={'class': 'form-control'}),


    )

    authors = forms.MultipleChoiceField(
        choices=models.Author.objects.all().values_list('nid',"name"),
        # widget=forms.SelectMultiple(attrs={'class': 'form-control'}),

    )


    #批量添加属性样式
    def __init__(self,*args,**kwargs):

        super().__init__(*args,**kwargs)

        for field_name,field in self.fields.items(): #orderdict(('username',charfield对象))

            field.widget.attrs.update({'class':'form-control'}) #update有更新无添加






def addbook(request):
    if request.method == 'GET':
        book_obj = AddBookForm()
        return render(request,'addbook.html',{"book_obj":book_obj})
    else:




{% load static %}
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css"
          integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">

</head>
<body>

<h1>书籍展示</h1>


<div class="container">
    <div class="row">
        <div class="col-md-8 col-md-offset-2">
            <form action="" method="post">

                {% csrf_token %}
                <div class="form-group">
                    {% for foo in book_obj %}
                        {{ foo.label }}
                        {{ foo }}

                    {% endfor %}

                </div>
{#              <div class="form-group">#}
{#                    {{ book_obj.title.label }}#}
{#                    {{ book_obj.title }}#}
{##}
{#              </div>#}
{#                <div class="form-group">#}
{#                    {{ book_obj.price.label }}#}
{#                    {{ book_obj.price }}#}
{#              </div>#}
{#                <div class="form-group">#}
{#                    {{ book_obj.publishDate.label }}#}
{#                    {{ book_obj.publishDate }}#}
{#              </div>#}
{#                <div class="form-group">#}
{#                    {{ book_obj.publish.label }}#}
{#                    {{ book_obj.publish }}#}
{##}
{##}
{#              </div>#}
{#                <div class="form-group">#}
{#                    {{ book_obj.authors.label }}#}
{#                    {{ book_obj.authors }}#}
{#              </div>#}


              <button type="submit" class="btn btn-success pull-right">提交</button>
            </form>



        </div>
    </div>

</div>


</body>
</html>

12.图书添加

from django import forms

class AddBookForm(forms.Form):
    title = forms.CharField(
        label="书名",
        # widget = forms.TextInput(attrs={'class': 'form-control'}),
    )
    price = forms.DecimalField(
        label="价格",
        max_digits=6,
        decimal_places=2,
        # widget=forms.TextInput(attrs={'class': 'form-control'}),
    )

    publishDate = forms.CharField(
        label="出版日期",
        widget=forms.TextInput(attrs={'type':'date',})
    )
    publish_id = forms.ChoiceField(
        #和上面比加了_id
        choices=models.Publish.objects.all().values_list('nid','name'),
        # widget=forms.Select(attrs={'class': 'form-control'}),


    )

    authors = forms.MultipleChoiceField(
        choices=models.Author.objects.all().values_list('nid',"name"),
        # widget=forms.SelectMultiple(attrs={'class': 'form-control'}),

    )


    #批量添加属性样式
    def __init__(self,*args,**kwargs):

        super().__init__(*args,**kwargs)

        for field_name,field in self.fields.items(): #orderdict(('username',charfield对象))

            field.widget.attrs.update({'class':'form-control'})






def addbook(request):
    if request.method == 'GET':
        book_obj = AddBookForm()
        return render(request,'addbook.html',{"book_obj":book_obj})
    else:

        book_obj =AddBookForm(request.POST)
        if book_obj.is_valid():
            print(book_obj.cleaned_data)

            data = book_obj.cleaned_data
            authors =data.pop("authors")
            new_book = models.Book.objects.create(
                **data
                # publishs = 对象
            )
            new_book.authors.add(*authors)


            return redirect('/index/')

        else:
            return render(request,"addbook.html",{"book_obj":book_obj})

另一种思路

class AddBookForm(forms.Form):
    title = forms.CharField(
        label="书名",
    )
    price = forms.DecimalField(
        label="价格",
        max_digits=6,
        decimal_places=2,
    )

    publishDate = forms.CharField(
        label="出版日期",
        widget=forms.TextInput(attrs={'type':'date',})

    )
    publish_id = forms.ChoiceField(
        choices=models.Publish.objects.all().values_list('nid','name'),  #[(),()]
    )
    authors=forms.MultipleChoiceField(
        choices=models.Author.objects.all().values_list('nid','name')

    )
    # publish = forms.ModelChoiceField(
    #     #指定数据库的数据
    #     # queryset  通过关键字
    #     queryset=models.Publish.objects.all()
    # )
    #
    # authors = forms.ModelMultipleChoiceField(
    #     queryset=models.Author.objects.all()
    # )
    #必须要在model中加入_ 要不然返回的是对象
    # def __str__(self):
    #     return self.name


    #批量添加属性样式
    def __init__(self,*args,**kwargs):

        super().__init__(*args,**kwargs)

        for field_name,field in self.fields.items(): #orderdict(('username',charfield对象))

            field.widget.attrs.update({'class':'form-control'})

13.ModelForm

form与model的终极结合,会根据你model中的字段转换成对应的form字段,并且并你生成标签等操作。\

    {% for field in book_form_obj %}
        <lable for="{{ field.id_for_label }}">{{ field.label }}</lable> 
                    循环添加  id_字段名字             id数据库的名字
        {{ field }}

    {% endfor %}

modelform类的写法

class BookForm(forms.ModelForm):

    class Meta:
        model = models.Book
        fields = "__all__"
        labels = {
            "title": "书名",
            "price": "价格"
        }
        widgets = {
            "password": forms.widgets.PasswordInput(attrs={"class": "c1"}),
            "publishDate": forms.widgets.DateInput(attrs={"type": "date"}),
        }

 class Meta下常用参数:

model = models.Book  # 对应的Model中的类
fields = "__all__"  # 字段,如果是__all__,就是表示列出所有的字段
exclude = None  # 排除的字段
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
error_messages = {
    'title':{'required':'不能为空',...} #每个字段的所有的错误都可以写,...是省略的意思
}

练习

把增加 和编辑使用了 modelform

from django.shortcuts import render,HttpResponse,redirect

# Create your views here.

from    app01 import models

def  index(request):
    book_objs = models.Book.objects.all()

    return render(request,'index.html',{'book_objs':book_objs} )



from django import forms



class BookModelForm(forms.ModelForm):
    class Meta:
        model = models.Book #只等Book表
        fields="__all__" #所有字段
        labels={
            "title":"书名",
            "price":"价格",
            "publish":"出版社",
            "authors":"作者",
            "publishDate":"出版日期",
 }

        widgets={"publishDate":forms.DateInput(attrs={'type':"date"})}




    def __init__(self,*args,**kwargs):

        super().__init__(*args,**kwargs)

        for field_name,field in self.fields.items(): #orderdict(('username',charfield对象))

            field.widget.attrs.update({'class':'form-control'})
            field.error_messages = {'required': '不能为空'}



#增加
def addbook(request):
    if request.method == 'GET':
        book_model_obj = BookModelForm()
        return render(request,'addbook.html',{"book_model_obj":book_model_obj})
    else:
        book_model_obj =BookModelForm(request.POST)
        if book_model_obj.is_valid():
            print(book_model_obj.cleaned_data)

            book_model_obj.save()

            return redirect('/index/')

        else:
            return render(request,"addbook.html",{"book_model_obj":book_model_obj})


#编辑
def editbook(request,book_id):
    old_objs = models.Book.objects.filter(pk=book_id) #
    if request.method == 'GET':
        old_obj = old_objs.first()
        book_model_obj = BookModelForm(instance=old_obj)

        return render(request,'editbook.html',{'book_model_obj':book_model_obj})
    else:
        book_model_obj =BookModelForm(request.POST,instance=old_objs.first())#instance
        if book_model_obj.is_valid():
            print(book_model_obj.cleaned_data)

            book_model_obj.save()#不写instance就是创建,指向老的就是update

            return redirect('/index/')

        else:
            return render(request,"addbook.html",{"book_model_obj":book_model_obj})











from django.http import JsonResponse
#ajax删除
def delbook(request):

    book_id = request.POST.get('book_id')
    print('book_id',book_id)
    models.Book.objects.filter(pk=book_id).delete()

    data = {'status':1}

    return JsonResponse(data)



html 相同

{% load static %}
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css"
          integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">

</head>
<body>

<h1>编辑书籍</h1>


<div class="container">
    <div class="row">
        <div class="col-md-8 col-md-offset-2">
            <form action="" method="post">

                {% csrf_token %}
                {% for foo in book_model_obj %}
                    <div class="form-group">
                    {{ foo.label }}
                    {{ foo }}
                    <span>{{ foo.errors.0 }}</span>
                    </div>

                {% endfor %}


              <button type="submit" class="btn btn-success pull-right">提交</button>
            </form>



        </div>
    </div>

</div>






</body>
</html>

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