Django Form 组件

文章对应的B站视频:https://www.bilibili.com/video/BV1Tu41127Ca/

Django系列文章对应的目录:https://www.cnblogs.com/emanlee/p/15860241.html

 

Django Form 组件

Django Form 组件用于对页面进行初始化,生成 HTML 标签,此外还可以对用户提交对数据进行校验(显示错误信息)。

报错信息显示顺序:

  • 先显示字段属性中的错误信息,然后再显示局部钩子的错误信息。
  • 若显示了字段属性的错误信息,就不会显示局部钩子的错误信息。
  • 若有全局钩子,则全局钩子是等所有的数据都校验完,才开始进行校验,并且全局钩子的错误信息一定会显示。

使用 Form 组件,需要先导入 forms:

from django import forms

 

接下来我们在 app01 目录下创建一个 My_forms.py:

app01/My_forms.py

from django import forms
from django.core.exceptions import ValidationError
from app01 import models

class EmpForm(forms.Form):
    name = forms.CharField(min_length=4, label="姓名", error_messages={"min_length": "太短了", "required": "该字段不能为空!"})
    age = forms.IntegerField(label="年龄")
    salary = forms.DecimalField(label="工资")

字段属性:

  • label:输入框前面的文本信息。
  • error_message:自定义显示的错误信息,属性值是字典, 其中 required 为设置不能为空时显示的错误信息的 key。

app01/views.py

from django.shortcuts import render, HttpResponse
from app01.My_forms import EmpForm
from app01 import models
from django.core.exceptions import ValidationError
# Create your views here.


def add_emp(request):
    if request.method == "GET":
        form = EmpForm()
        return render(request, "add_emp.html", {"form": form})
    else:
        form = EmpForm(request.POST)
        if form.is_valid():  # 进行数据校验
            # 校验成功
            data = form.cleaned_data  # 校验成功的值,会放在cleaned_data里。
            data.pop('r_salary')
            print(data)

            models.Emp.objects.create(**data)
            return HttpResponse(
                'ok'
            )
            # return render(request, "add_emp.html", {"form": form})
        else:
            print(form.errors)    # 打印错误信息
            clean_errors = form.errors.get("__all__")
            print(222, clean_errors)
        return render(request, "add_emp.html", {"form": form, "clean_errors": clean_errors})

 


app01/urls.py 文件添加以下规则:

from django.urls import path
from . import views

urlpatterns = [
    path('add_emp/', views.add_emp)
]

 

settings.py 配置:

TEMPLATES 里面的 DIRS
import os
TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [os.path.join(BASE_DIR, 'app01')],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

 MIDDLEWARE,把下面的'django.middleware.csrf.CsrfViewMiddleware',注释掉

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    #'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

 

 

HTML 模版:

app01/add_emp.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
 
<h3>添加员工</h3>
 
{#1、自己手动写HTML页面#}
<form action="" method="post">
    <p>姓名:<input type="text" name="name"></p>
    <p>年龄:<input type="text" name="age"></p>
    <p>工资:<input type="text" name="salary"></p>
    <input type="submit">
</form>
 
{#2、通过form对象的as_p方法实现#}
{#<form action="" method="post" novalidate>#}
{#    {% csrf_token %}#}
{#    {{ form.as_p }}#}
{#    <input type="submit">#}
{#</form>#}
 
{#3、手动获取form对象的字段#}
{#<form action="" method="post" novalidate>#}
{#    {% csrf_token %}#}
{#    <div>#}
{#        <label for="id_{{ form.name.name }}">姓名</label>#}
{#        {{ form.name }} <span>{{ form.name.errors.0 }}</span>#}
{#    </div>#}
{#    <div>#}
{#        <label for="id_{{ form.age.name }}">年龄</label>#}
{#        {{ form.age }} <span>{{ form.age.errors.0 }}</span>#}
{#    </div>#}
{#    <div>#}
{#        <label for="id_salary">工资</label>#}
{#        {{ form.salary }} <span>{{ form.salary.errors.0 }}</span>#}
{#    </div>#}
{#    <input type="submit">#}
{#</form>#}
 
 
{#4、用for循环展示所有字段#}
{#<form action="" method="post" novalidate>#}
{#    {% csrf_token %}#}
{#    {% for field in form %}#}
{#        <div>#}
{#            <label for="id_{{ field.name }}">{{ field.label }}</label>#}
{#            {{ field }} <span>{{ field.errors.0 }}</span>#}
{#        </div>#}
{#    {% endfor %}#}
{#    <input type="submit">#}
{#</form>#}
 
</body>
</html>

http://127.0.0.1:8003/add_emp/

 


运行结果如下图所示:

 

把 app01/add_emp.html 的 #1 注释掉, #2 去掉注释,然后测试.

  

 

 

局部钩子和全局钩子

定义 Form 类:

app01/My_forms.py

from django import forms
from django.core.exceptions import ValidationError
from app01 import models
class EmpForm(forms.Form):
    name = forms.CharField(min_length=5, label="姓名", error_messages={"required": "该字段不能为空!",
                                                                     "min_length": "用户名太短。"})
    age = forms.IntegerField(label="年龄")
    salary = forms.DecimalField(max_digits=5, decimal_places=2, label="工资")
    r_salary = forms.DecimalField(max_digits=5, decimal_places=2, label="请再输入工资")


    def clean_name(self):  # 局部钩子
        val = self.cleaned_data.get("name")


        if val.isdigit():
            raise ValidationError("用户名不能是纯数字")
        elif models.Emp.objects.filter(name=val):
            raise ValidationError("用户名已存在!")
        else:
            return val

    def clean(self):  # 全局钩子 确认两次输入的工资是否一致。
        val = self.cleaned_data.get("salary")
        r_val = self.cleaned_data.get("r_salary")


        if val == r_val:
            return self.cleaned_data
        else:
            raise ValidationError("请确认工资是否一致。")

 


views.py 文件代码:

app01/views.py

def add_emp(request):
    if request.method == "GET":
        form = EmpForm()  # 初始化form对象
        return render(request, "add_emp.html", {"form":form})
    else:
        form = EmpForm(request.POST)  # 将数据传给form对象
        if form.is_valid():  # 进行校验
            data = form.cleaned_data
            data.pop("r_salary")
            models.Emp.objects.create(**data)
            return redirect("/index/")
        else:  # 校验失败
            clear_errors = form.errors.get("__all__")  # 获取全局钩子错误信息
            return render(request, "add_emp.html", {"form": form, "clear_errors": clear_errors})

 


模板文件代码如下:

app01/add_emp.html

<form action="" method="post" novalidate>
    {% csrf_token %}
    <div>
        <label for="id_{{ form.name.name }}">姓名</label>
        {{ form.name }} <span>{{ form.name.errors.0 }}</span>
    </div>
    <div>
        <label for="id_{{ form.age.name }}">年龄</label>
        {{ form.age }} <span>{{ form.age.errors.0 }}</span>
    </div>
    <div>
        <label for="id_salary">工资</label>
        {{ form.salary }} <span>{{ form.salary.errors.0 }}{{ clear_errors.0 }}</span>
    </div>
    <div>
        <label for="id_r_salary">请再输入工资</label>
        {{ form.r_salary }} <span>{{ form.r_salary.errors.0 }}{{ clear_errors.0 }}</span>
    </div>
    <input type="submit">
</form>

 


运行结果如下图所示:

 

 

 

https://www.runoob.com/django/django-form-component.html

 

posted @ 2022-01-30 16:23  emanlee  阅读(109)  评论(0编辑  收藏  举报