Django的Form组件

〖Python〗-- Django的Form组件

【Django的Form组件】

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

Form类的使用：

1、定义规则：

from django.forms import Form
from django.forms import fields
class xxx(Form):
    xx = fields.CharField(max_lenghth=,min_lenghth=,required=True,error_message=)

2、使用：

obj = xxx(request.POST)
# 是否校验成功
v = obj.is_valid()
    # html标签name属性 = Form类字段名
 
obj.is_valid()验证通过返回True，失败则返回False
 
# 所有错误信息
obj.errors
 
# 正确信息
obj.cleaned_data

登录和注册案例：

from django.shortcuts import render,HttpResponse,redirect

from django.forms import Form
from django.forms import fields
class LoginForm(Form):
    # 正则验证: 不能为空,6-18
    username = fields.CharField(
        max_length=18,
        min_length=6,
        required=True,
        error_messages={
            'required': '用户名不能为空',
            'min_length': '太短了',
            'max_length': '太长了',
        }
    )
    # 正则验证: 不能为空，16+
    password = fields.CharField(min_length=16,required=True)
    # email = fields.EmailField()
    # email = fields.GenericIPAddressField()
    # email = fields.IntegerField()


def login(request):
    if request.method == "GET":
        return render(request,'login.html')
    else:
       obj = LoginForm(request.POST)
       if obj.is_valid():
           # 用户输入格式正确
           print(obj.cleaned_data) # 字典类型
           return redirect('http://www.baidu.com')
       else:
           # 用户输入格式错误
           return render(request,'login.html',{'obj':obj})
View.py
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<form method="POST" action="/login/">
    {% csrf_token %}
    用户名:<input type="text" name="username">{{ obj.errors.username.0 }}<br>
    密码 &nbsp;&nbsp;:<input type="password" name="password">{{ obj.errors.password.0 }}<br>
    <input type="submit" value="提交">

</form>

</body>
</html>
login.html

基于Form和Ajax提交实现用户登录案例：两种验证方式

from django.shortcuts import render,redirect,HttpResponse
from django.forms import Form
from django.forms import fields
from django.forms import widgets

class LoginForm(Form):
    user = fields.CharField(required=True)
    pwd = fields.CharField(min_length=18)


def login(request):
    if request.method == 'GET':
        return render(request,'login.html')
    else:
        obj = LoginForm(request.POST)
        if obj.is_valid():
            print(obj.cleaned_data)
            return redirect('http://www.baidu.com')
        return render(request,'login.html',{'obj': obj})

def ajax_login(request):
    import json
    ret = {'status': True,'msg': None}
    obj = LoginForm(request.POST)
    if obj.is_valid():
        print(obj.cleaned_data)
    else:
        # print(obj.errors) # obj.errors对象
        ret['status'] = False
        ret['msg'] = obj.errors
    v = json.dumps(ret)
    return HttpResponse(v)

#
# class TestForm(Form):
#     t1 = fields.CharField(
#         required=True,
#         max_length=8,
#         min_length=2,
#         error_messages={
#             'required': '不能为空',
#             'max_length': '太长',
#             'min_length': '太短',
#         }
#     )
#     t2 = fields.IntegerField(
#         min_value=10,
#         max_value=1000,
#         error_messages={
#             'required': 't2不能为空',
#             'invalid': 't2格式错误，必须是数字',
#             'min_value': '必须大于10',
#             'max_value': '必须小于1000',
#         },
#     )
#     t3 = fields.EmailField(
#         error_messages={
#             'required': 't3不能为空',
#             'invalid': 't3格式错误，必须是邮箱格式',
#         }
#     )





class TestForm(Form):
    t1 = fields.CharField(required=True,max_length=8,min_length=2,
        error_messages={
            'required': '不能为空',
            'max_length': '太长',
            'min_length': '太短',
        }
    )
    t2 = fields.EmailField()

def test(request):
    if request.method == "GET":
        obj = TestForm()
        return render(request,'test.html',{'obj': obj})
    else:
        obj = TestForm(request.POST)
        if obj.is_valid():
            print(obj.cleaned_data)
        else:
            print(obj.errors)
        return render(request,'test.html',{'obj':obj})



class RegiterForm(Form):
    user = fields.CharField(min_length=8)
    email = fields.EmailField()
    password = fields.CharField()
    phone = fields.RegexField('139\d+')


def register(request):
    if request.method == 'GET':
        obj = RegiterForm()
        return render(request,'register.html',{'obj':obj})
    else:
        obj = RegiterForm(request.POST)
        if obj.is_valid():
            print(obj.cleaned_data)
        else:
            print(obj.errors)
        return render(request,'register.html',{'obj':obj})
View.py
"""s4day77 URL Configuration

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/1.10/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  url(r'^$', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  url(r'^$', Home.as_view(), name='home')
Including another URLconf
    1. Import the include() function: from django.conf.urls import url, include
    2. Add a URL to urlpatterns:  url(r'^blog/', include('blog.urls'))
"""
from django.conf.urls import url
from django.contrib import admin
from app01 import views
urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^login/', views.login),
    url(r'^ajax_login/', views.ajax_login),
    url(r'^test/', views.test),
    url(r'^register/', views.register),
]
urls.py
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <h1>用户登录</h1>
    <form id="f1" action="/login/" method="POST">
        {% csrf_token %}
        <p>
            <input type="text" name="user" />{{ obj.errors.user.0 }}
        </p>
        <p>
            <input type="password" name="pwd" />{{ obj.errors.pwd.0 }}
        </p>
        <input type="submit" value="提交" />
        <a onclick="submitForm();">提交</a>
    </form>
    <script src="/static/jquery-1.12.4.js"></script>
    <script>
        function submitForm(){
            $('.c1').remove();
            $.ajax({
                url: '/ajax_login/',
                type: 'POST',
                data: $('#f1').serialize(),// user=alex&pwd=456&csrftoen=dfdf\
                dataType:"JSON",
                success:function(arg){
                    console.log(arg);
                    if(arg.status){

                    }else{
                        $.each(arg.msg,function(index,value){
                            console.log(index,value);
                            var tag = document.createElement('span');
                            tag.innerHTML = value[0];
                            tag.className = 'c1';
                            $('#f1').find('input[name="'+ index +'"]').after(tag);
                        })
                    }
                }
            })
        }
    </script>
</body>
</html>
login.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <form action="/test/" method="POST" novalidate>
        {% csrf_token %}
        <p>
            {{ obj.t1 }}{{ obj.errors.t1.0 }}
        </p>
        <p>
            {{ obj.t2 }}{{ obj.errors.t2.0 }}
        </p>
        <input type="submit" value="提交" />
    </form>
</body>
</html>
test.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>

    <form action="/register/" method="POST" novalidate>
        {% csrf_token %}
        <p>
            {{ obj.user }} {{ obj.errors.user.0 }}
        </p>
        <p>
            {{ obj.email }} {{ obj.errors.email.0 }}
        </p>
        <p>
            {{ obj.password }} {{ obj.errors.password.0 }}
        </p>
        <p>
            {{ obj.phone }} {{ obj.errors.phone.0 }}
        </p>
        <input type="submit" value="提交"  />
    </form>
</body>
</html>
register.html

总结：

- Ajax，仅用验证功能
- Form，验证功能，生成HTML标签

班级、学生案例：

from django.shortcuts import render,redirect
from app01 import models
from django.forms import Form
from django.forms import fields
from django.forms import widgets



class ClassForm(Form):
    title = fields.RegexField('全栈\d+')

def class_list(request):
    cls_list = models.Classes.objects.all()
    return render(request,'class_list.html',{'cls_list':cls_list})

def add_class(request):
    if request.method == "GET":
        obj = ClassForm()
        return render(request,'add_class.html',{'obj': obj})
    else:
        obj = ClassForm(request.POST)
        if obj.is_valid():
            # obj.cleaned_data # 字典
            # 数据库创建一条数据
            # print(obj.cleaned_data)
            # models.Classes.objects.create(title=obj.cleaned_data['tt'])

            models.Classes.objects.create(**obj.cleaned_data)
            return redirect('/class_list/')
        return render(request,'add_class.html',{'obj': obj})

def edit_class(request,nid):
    if request.method == "GET":
        row = models.Classes.objects.filter(id=nid).first()
        # 让页面显示初始值
        # obj = ClassForm(data={'title': 'asdfasdfasdfas'})
        obj = ClassForm(initial={'title': row.title})
        return render(request,'edit_class.html',{'nid': nid,'obj':obj})
    else:
        obj = ClassForm(request.POST)
        if obj.is_valid():
            models.Classes.objects.filter(id=nid).update(**obj.cleaned_data)
            return redirect('/class_list/')
        return render(request,'edit_class.html',{'nid': nid,'obj':obj})



class StudentForm(Form):
    name = fields.CharField(
        min_length=2,
        max_length=6,
        widget=widgets.TextInput(attrs={'class': 'form-control'})
    )
    email = fields.EmailField(widget=widgets.TextInput(attrs={'class': 'form-control'}))
    age = fields.IntegerField(min_value=18,max_value=25,widget=widgets.TextInput(attrs={'class': 'form-control'}))
    cls_id = fields.IntegerField(
        # widget=widgets.Select(choices=[(1,'上海'),(2,'北京')])
        widget=widgets.Select(choices=models.Classes.objects.values_list('id','title'),attrs={'class': 'form-control'})
    )


def student_list(request):

    stu_list = models.Student.objects.all()
    return render(request,'student_list.html',{'stu_list':stu_list})

def add_student(request):
    if request.method == "GET":
        obj = StudentForm()
        return render(request,'add_student.html',{'obj':obj})
    else:
        obj = StudentForm(request.POST)
        if obj.is_valid():
            models.Student.objects.create(**obj.cleaned_data)
            return redirect('/student_list/')
        return render(request,'add_student.html',{'obj':obj})



def edit_student(request,nid):
    if request.method == "GET":
        row = models.Student.objects.filter(id=nid).values('name','email','age','cls_id').first()
        obj = StudentForm(initial=row)
        return render(request,'edit_student.html',{'nid':nid,'obj': obj})
    else:
        obj = StudentForm(request.POST)
        if obj.is_valid():
            models.Student.objects.filter(id=nid).update(**obj.cleaned_data)
            return redirect('/student_list/')
        return render(request,'edit_student.html',{'nid':nid,'obj': obj})
View.py
"""s4day77example URL Configuration

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/1.10/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  url(r'^$', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  url(r'^$', Home.as_view(), name='home')
Including another URLconf
    1. Import the include() function: from django.conf.urls import url, include
    2. Add a URL to urlpatterns:  url(r'^blog/', include('blog.urls'))
"""
from django.conf.urls import url
from django.contrib import admin
from app01 import views
urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^class_list/', views.class_list),
    url(r'^add_class/', views.add_class),
    url(r'^edit_class/(\d+)/', views.edit_class),

    url(r'^student_list/', views.student_list),
    url(r'^add_student/', views.add_student),
    url(r'^edit_student/(\d+)/', views.edit_student),
]
urls.py
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <h1>班级列表</h1>
    <div>
        <a href="/add_class/">添加</a>
    </div>
    <ul>
        {% for row in cls_list %}
            <li>{{ row.title }} <a href="/edit_class/{{ row.id }}/">编辑</a>  </li>
        {% endfor %}
    </ul>
</body>
</html>
class_list.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <h1>添加班级</h1>
    <form method="POST" action="/add_class/" novalidate>
        {% csrf_token %}
        {{ obj.title }} {{ obj.errors.title.0 }}
        <input type="submit" value="提交" />
    </form>
</body>
</html>
add_class.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <h1>编辑班级</h1>
    <form method="POST" action="/edit_class/{{ nid }}/">
        {% csrf_token %}
        <p>
            {{ obj.title }} {{ obj.errors.title.0 }}
        </p>
        <input type='submit' value="提交" />
    </form>
</body>
</html>
edit_class.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <h1>学生列表</h1>
    <a href="/add_student/">添加</a>
    <ul>
        {% for row in stu_list %}
            <li>{{ row.name }}-{{ row.email }}-{{ row.age }}-{{ row.cls_id }}-{{ row.cls.title }}   <a href="/edit_student/{{ row.id }}/">编辑</a></li>
        {% endfor %}
    </ul>
</body>
</html>
student_list.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <h1>添加学生</h1>
    <form action="/add_student/" method="POST">
        {% csrf_token %}
        <p>
            {{ obj.name }}
        </p>
        <p>
            {{ obj.email }}
        </p>
        <p>
            {{ obj.age }}
        </p>
        <p>
            {{ obj.cls_id }}
        </p>
        <input type="submit" value="提交" />
    </form>
</body>
</html>
add_student.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <link rel="stylesheet" href="/static/bootstrap-3.3.5-dist/css/bootstrap.css"/>
</head>
<body>


    <div style="width: 500px;margin: 0 auto;">
        <form class="form-horizontal" method="POST" action="/edit_student/{{ nid }}/">
            {% csrf_token %}
            <div class="form-group">
                <label class="col-sm-2 control-label">姓名：</label>

                <div class="col-sm-10">
                    {{ obj.name }}
                </div>
            </div>
            <div class="form-group">
                <label class="col-sm-2 control-label">邮箱：</label>

                <div class="col-sm-10">
                    {{ obj.email }}
                </div>
            </div>
             <div class="form-group">
                <label class="col-sm-2 control-label">年龄：</label>

                <div class="col-sm-10">
                    {{ obj.age }}
                </div>
            </div>
             <div class="form-group">
                <label class="col-sm-2 control-label">班级：</label>

                <div class="col-sm-10">
                    {{ obj.cls_id }}
                </div>
            </div>
            <div class="form-group">
                <div class="col-sm-offset-2 col-sm-10">
                    <input type="submit" class="btn btn-default" value="提交" />
                </div>
            </div>
        </form>
    </div>
</body>
</html>
edit_student.html

Form组件的上传功能

from django.shortcuts import render,redirect,HttpResponse
from django.forms import Form
from django.forms import fields
from django.forms import widgets
from app01 import models
import os


class F2Form(Form):
    user = fields.CharField()
    fafafa = fields.FileField()

def f1(request):
    if request.method=="GET":
        return render(request,'f1.html')
    else:
        print(request.FILES)
        file_obj = request.FILES.get("fafafa")
        f = open(os.path.join('static',file_obj.name),'wb')
        for chunk in file_obj.chunks():
            f.write(chunk)
        f.close()
        return render(request,'f1.html')

def f2(request):
    if request.method == "GET":
        obj = F2Form()
        return render(request,'f2.html',{'obj':obj})
    else:
        obj = F2Form(data=request.POST,files=request.FILES)
        if obj.is_valid():
            print(obj.cleaned_data.get("fafafa").name)
            print(obj.cleaned_data.get("fafafa").size)
        return render(request,'f2.html',{'obj':obj})
View.py
f1.html
f2.html

Form类的字段和插件

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;

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')
View Code

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())zidi

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.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：

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
    )
View Code

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')
View Code

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>
View Code

关于对字段认证[clean，clean_字段]的补充（关于错误信息）

class RegesterForm(Form):
    username = fields.CharField(
        widget=widgets.TextInput(
            attrs={"class": "form-control",
                   "placeholder": "用户名",
                   }),
        error_messages={
            "required": "内容不能为空",
            "invalid": "格式错误,请重新输入！", })
 
    nickname = fields.CharField(
        widget=widgets.TextInput(
            attrs={"class": "form-control",
                   "placeholder": "即昵称",
                   }),
        error_messages={
            "required": "内容不能为空",
            "invalid": "格式错误,请重新输入！", })
 
    email = fields.EmailField(
        widget=widgets.TextInput(
          attrs={
              "class": "form-control",
              "placeholder": "请输入您查用邮箱",
          }),
        error_messages = {
            "required": "内容不能为空",
            "invalid": "格式错误,请重新输入！",}
    )
 
    password = fields.CharField(
        widget=widgets.PasswordInput(
            attrs={"class": "form-control",
                   "placeholder": "密码,必须包含数字,字母！",
                   }),
        error_messages={
            "required": "内容不能为空",
            "invalid": "格式错误,请重新输入！", })
 
    passwords = fields.CharField(
        widget=widgets.PasswordInput(
            attrs={"class": "form-control",
                   "placeholder": "请输入确认密码",
                   }),
        error_messages={
            "required": "内容不能为空",
            "invalid": "格式错误,请重新输入！", })
 
    avatar = fields.FileField(
        widget=widgets.FileInput(
            attrs={'id':"imgSelect",}),
    )
    code = fields.CharField(
        widget=widgets.TextInput(
            attrs={
                "class": "form-control",
                "placeholder": "验证码",
            },)
    )
    def __init__(self,request,*args,**kwargs):
        super(RegesterForm,self).__init__(*args,**kwargs)
        self.request = request
 
    def clean_code(self):
        input_code = self.cleaned_data["code"]
        session_code = self.request.session.get("code")
        if input_code.upper() == session_code.upper():
            return input_code
        raise ValidationError("验证码错误，请重新输入!")
    #自定义字段验证方法，获取错误信息的方式不变，还是   对象.errors.字段名.0
 
    def clean(self):
        p1 = self.cleaned_data.get("password")
        p2 = self.cleaned_data.get("passwords")
        if p1 == p2:
            return self.cleaned_data
        else:
            self.add_error("passwords",ValidationError("输入的密码不一致！"))　

 

ModelForm

使用Django开发web程序阶段回顾：

1.手动对单表进行增、删、该、查，手动把ORM操作获取的数据渲染到模板；（阶段1）

2.Form组件（类），自动生成标签（input、select），并对用户输入的数据做规则验证；（阶段2）

3.ModelForm顾名思义就Form和Django的Model数据库模型结合体，可以简单、方便得对数据库进行增加、编辑操作和验证标签的生成；

Form组件和ModelForm的区别

ModelForm是Django Model.py和Form组件的结合体，可以简单/快速使用 Form验证和数据库操作功能，但不如Form组件灵活，如果在使用Django做web开发过程中验证的数据和数据库字段相关（可以对表进行增、删、改操，注意 Many to many字段，也可以级联操作第3张关系表；），建议优先使用ModelForm，用起来更方便些，但是在使用ModelForm的时候慎用fields='__all__'，获取数据库所有字段势必造成性能损耗；

 1.使用ModelForm

 前端： 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
{{ form_obj.as_p }}
{#<p>姓名：{{form_obj.name  }}</p>#}
</body>
</html>
View Code

后端视图：

from app02 import models
from django.forms import ModelForm
class UserModalForm(ModelForm):
    class Meta:
        model=models.UserInfo #(该字段必须为 model  数据库中表)
        fields= '__all__'   #(该字段必须为 fields 数据库中表)

def add(request):
     # 实例化models_form
    if request.method=='GET':
        obj = UserModalForm()
        return render(request,'rbac/user_add.html',locals())
    else:
        obj=UserModalForm(request.POST)
        if obj.is_valid():
            data=obj.cleaned_data
            obj.save()  #form验证通过直接 添加用户信息到数据库
        return render(request, 'rbac/user_add.html', locals())
View Code

2.每一个ModelForm都依托一个Model，需要先设计Model之后，在设计对应的ModelForm。

假设已定义好Model，如下

class Book(models.Model):
    name = models.CharField(max_length=100)
    authors = models.ManyToManyField(Author)

则对应需要设计一个ModelForm

from django.forms import ModelForm
import Book

class BookForm(ModelForm):
    class Meta:
        model=Book
    def clean_<fieldname>:

可参考：https://www.cnblogs.com/DI-DIAO/p/8978780.html

 

posted @ 2018-08-07 10:05  小L小  阅读(224)  评论(0)  编辑  收藏  举报