django中的forms组件(权限信息校验，增删改查)

1.用处

　　1、用户请求数据验证

　　2、自动生成错误信息

　　3、打包用户提交的正确信息

　　4、如果其中有一个错误了，其他的正确，则保留上次输入的内容

　　5、自动创建input标签并可以设置样式

　　6.基于forms实现增删改查

2.使用方法

对于注册信息进行校验

在应用下创建一个forms.py文件（起什么名无所谓，后面在视图函数中直接导入进来使用）

from django import forms

from django.forms import widgets

from django.core.exceptions import NON_FIELD_ERRORS, ValidationError

class UserInfo(forms.Form):

    username = forms.CharField(

        required=True,   # 标明是必填字段，不能为空

        min_length=4, max_length=12,

        label="姓名",     # 给定字段名称，直接把username换成了姓名

        error_messages={"required": "用户名不能为空！！"},

        widget=widgets.TextInput(attrs={"placeholder": "用户名", "class": "form-control"}) # 自动生成input框

    )

    password = forms.CharField(

        widget=widgets.PasswordInput(attrs={"placeholder":"密码","class":"form-control"}),

        label="密码",

    )

    sec_pwd = forms.CharField(

        required=True,

        label="二次密码",

        widget=widgets.PasswordInput(attrs={"placeholder":"二次密码","class":"form-control"})

    )

    age = forms.IntegerField(

        label="年龄",

        widget = widgets.NumberInput(attrs={"placeholder":"年龄","class":"form-control"}),

        error_messages={"required": "输入不对！！"},

    )

    email = forms.EmailField(

        widget=widgets.EmailInput(attrs={"placeholder":"邮箱","class":"form-control"}),

        label="邮箱",

        error_messages={"invalid": "格式错误"}

    )

    # 定制化二次错误信息

    # 局部钩子

    # 注意这里必须是以clean_  开头，可以查看源码,下面得到的val都是字符串类型

    def clean_username(self):

        val = self.cleaned_data.get("username")

        if not val.isdigit():

            return val

        else:

            raise ValidationError("用户名非纯数字")

    def clean_password(self):

        val = self.cleaned_data.get("password")

        if len(val) > 3:

            return val

        else:

            raise ValidationError("密码太短")

    def clean_age(self):

        val = self.cleaned_data.get("age")

        if int(val) > 18:

            return val

        else:

            raise ValidationError("岁数太小")

    # 全局钩子

    # 对于两次输入的密码进行校验是否一致

    def clean(self):

        password = self.cleaned_data.get("password")

        sec_pwd = self.cleaned_data.get("sec_pwd")

        if password == sec_pwd:

            return self.cleaned_data

        else:

            raise ValidationError("两次密码不一致")

　　这个类到底干了什么事呢？？你在解释器中打印就会发现，第一件事就是将自己显示成HTML。form对象做的第二件事就是来校验信息

　　调用任何绑定form的is_valid()方法，就可以知道它的数据是否合法

　　Django的form系统自动寻找匹配的函数方法，该方法名称以 clean_ 开头，并以字段名称结束。如果有这样的方法，它将在校验时被调用。这属于一次额外校验

　　如果存在异常，我们抛出一个 forms.ValidationError 型异常，这个异常的描述会被作为错误列表中的一项显示给用户

views.py

from django.shortcuts import render,HttpResponse

# Create your views here.

from app01.form import UserInfo

def index(request):

    # 定制化提示信息，

    if request.method=="POST":

        form = UserInfo(request.POST)

        # 如果全部输入信息有效

        if form.is_valid():

            return HttpResponse("添加成功")

        else:

            # 打印输入的信息

            print("---",form.cleaned_data)      # 得到一个字典

            print("???",form.errors)             # ErrorDict : {"校验错误的字段":["错误信息",]}

            print("!!!",form.errors.get("email"))   # ErrorList ["错误信息",]

            g_error = form.errors.get("__all__")

            print("+++",g_error)     # <ul class="errorlist nonfield"><li>两次密码不一致</li></ul>

            if g_error:

                g_error = g_error[0]   # 直接获取你自己的错误提示，即两次密码不一致

            return render(request, "index.html", locals())

    else:

        form = UserInfo()

        return render(request, "index.html", locals())

这里form.py和创建的视图函数衔接关键点就在于 form = UserInfo(request.POST)

模板渲染：

方式一：

以p标签的样式展现出来，当然也能以能table标签展示

index.html

<!doctype html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <meta name="viewport"

          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">

    <meta http-equiv="X-UA-Compatible" content="ie=edge">

    <title>Document</title>

    <style>

        .error {

            color: red;

        }

    </style>

    <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.css">

</head>

<body>

<h3>注册用户</h3>

<div class="container">

    <div class="row">

        <div class="col-md-8 col-md-offset-2">

            {# 这个novalidate很重要啊，没有这个后面自己定制的错误提示无法渲染出来 #}

            {# 自己编写表单验证插件的时候，使用它可以避免和默认的表单验证冲突 #}
<form action="" method="post" novalidate>

                {% csrf_token %}

                {{ form.as_p }}

                <input type="submit">

           </form>

        </div>

    </div>

</div>

</body>

</html>

# 要注意这里form表单中添加的属性novalidate，它能够避免和默认的表单验证发生冲突

方式二：

书写相对麻烦

<form action="" method="post" novalidate>

      {% csrf_token %}

                <div>

                    <p>姓名</p>

                    {{ form.username }}

                </div>

                <div>

                    <p>密码</p>

                    {{ form.password }}

                </div>

                <div>

                    <p>二次密码</p>

                    {{ form.sec_pwd }}

                </div>

                <div>

                    <p>年龄</p>

                    {{ form.age }}

                </div>

                <div>

                    <p>年龄</p>

                    {{ form.email }}

                </div>

                <input type="submit">

 </form>

方式三（常用）：

<form action="" method="post" novalidate>

        {% csrf_token %}

                {% for foo in form %}

                    <div class="form-group">

                        {# 渲染出lable标签，标签后面是输入框 #}

                        <lable>{{ foo.label }}</lable>{{ foo }}

                        {# 专门定制报错信息 #}

                        <span class="error pull-right">{{ foo.errors.0 }}</span>

                        {# 对于二次输入报错信息进行设置 #}

                        {% if foo.label == "二次密码" %}

                            <span class="error pull-right">{{ g_error|default_if_none:"" }}</span>

                        {% endif %}

                    </div>

                {% endfor %}

                <input type="submit" class="btn btn-default btn-sm">

            </form>

3.基于forms组件的ModelForm实现的增删改查

models.py

from django.db import models

class Depart(models.Model):

    caption = models.CharField(max_length=32)

    def __str__(self):

        return self.caption

class Role(models.Model):

    title = models.CharField(max_length=32)

    def __str__(self):

        return self.title

class User(models.Model):

    name = models.CharField(verbose_name='姓名',max_length=32)

    depart = models.ForeignKey(verbose_name='部门',to='Depart',on_delete=models.CASCADE)

    gender_choices = (

        (1,'男'),

        (2,'女'),

    )

    gender = models.IntegerField(verbose_name='性别',choices=gender_choices,default=1)

    roles = models.ManyToManyField(verbose_name='角色',to='Role')

urls.py

from django.contrib import admin

from django.urls import path,re_path

from app01 import views

urlpatterns = [

    path('admin/', admin.site.urls),

    re_path('user/list/$', views.user_list),

    re_path('user/add/$', views.user_add),

    re_path('user/edit/(?P<uid>\d+)/$', views.user_edit),

    re_path('user/del/(?P<uid>\d+)/$', views.user_del),

]

views.py

from django.shortcuts import render,redirect

from app01 import models

def user_list(request):

    user_queryset = models.User.objects.all()

    return render(request,'user_list.html',{'user_queryset':user_queryset})

from django import forms

class UserForm(forms.ModelForm):

    class Meta:

        model = models.User

        fields = '__all__'

        # fields = ['name','depart']

        widgets = {

            'name':forms.TextInput(attrs={'class':'form-control'}),

            'depart':forms.Select(attrs={'class':'form-control'}),

            'gender':forms.Select(attrs={'class':'form-control'}),

            'roles':forms.SelectMultiple(attrs={'class':'form-control'}),

        }

        error_messages = {

            'name':{

                'required':'用户名不能为空'

            }

        }

def user_add(request):

    if request.method == "GET":

        form = UserForm()

    else:

        form = UserForm(request.POST)

        if form.is_valid():

            print('通过验证')

            form.save()

            return redirect('/user/list/')

    return render(request,'user_add.html',{'form':form})

def user_edit(request,uid):

    obj = models.User.objects.filter(id=uid).first()

    if request.method =='GET':

        form = UserForm(instance=obj)

        return render(request,'user_edit.html',{'form':form})

    else:

        form = UserForm(data=request.POST,instance=obj)

        if form.is_valid():

            form.save()

            return redirect('/user/list/')

        else:

            return render(request, 'user_edit.html', {'form': form})

def user_del(request,uid):

    models.User.objects.filter(id=uid).delete()

    return redirect('/user/list/')

user_list.html

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>Title</title>

    <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">

</head>

<body>

    <div class="container">

        <a href="/user/add/" class="btn btn-primary">添加</a>

        <table class="table table-bordered">

            <thead>

                <tr>

                    <th>名称</th>

                    <th>性别</th>

                    <th>部门</th>

                    <th>角色</th>

                    <th>操作</th>

                </tr>

            </thead>

            <tbody>

                {% for row in user_queryset %}

                    <tr>

                        <td>{{ row.name }}</td>

                        <td>{{ row.get_gender_display }}</td>

                        <td>{{ row.depart.caption }}</td>

                        <td>

                            {% for node in row.roles.all %}

                                <span>{{ node.title }}</span>

                            {% endfor %}

                        </td>

                        <td>

                            <a href="/user/edit/{{ row.id }}/">编辑</a>

                            <a href="/user/del/{{ row.id }}/">删除</a>

                        </td>

                    </tr>

                {% endfor %}

            </tbody>

        </table>

    </div>

</body>

</html>

user_edit.html

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>Title</title>

     <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">

</head>

<body>

    <h1>编辑用户</h1>

    <form method="post" novalidate>

        {% csrf_token %}

        {% for field in form %}

            <div>{{ field.label }}{{ field }} {{ field.errors.0 }}</div>

        {% endfor %}

        <input type="submit" value="提交">

    </form>

</body>

</html>

user_add.html

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>Title</title>

     <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">

</head>

<body>

    <div class="container">

        <h1>添加用户</h1>

        <form method="post" class="form-horizontal" novalidate>

            {% csrf_token %}

            {% for field in form %}

                <div class="form-group">

                    <label class="col-sm-2 control-label">{{ field.label }} </label>

                    <div class="col-sm-10">

                      {{ field }} {{ field.errors.0 }}

                    </div>

                  </div>

            {% endfor %}

            <input type="submit" value="提交">

        </form>

    </div>

</body>

</html>

效果：

django中的forms组件(权限信息校验，增删改查)

这里其他效果：

django中的forms组件(权限信息校验，增删改查)

秒客网

django中的forms组件(权限信息校验，增删改查)

1.用处

2.使用方法

3.基于forms组件的ModelForm实现的增删改查

相关文章