Django Forms组件实战:从基础校验到钩子验证详解

Mason
Mason
发布时间:2026-10-13 | 6人浏览过
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本文深入解析Django中forms组件的核心用法,涵盖字段渲染的三种方式、错误信息显示及输入重置机制。通过注册用户实例,详细演示如何编写模型与视图,并重点讲解局部钩子(clean_name)与全局钩子(clean)的实现,包括密码一致性校验及错误信息的模板处理,帮助开发者掌握Django表单验证的最佳实践。

在Django中编写form表单的过程,与定义模型系统非常相似。在模型定义里,每个字段对应数据库表的一列;而在form表单中,每个字段则对应HTML <form> 标签内的一个 <input> 元素。

一、forms组件基础

主要功能:字段校验

本节以注册用户场景为例进行讲解。

模型定义:models.py

class UserInfo(models.Model):
  name=models.CharField(max_length=32)
  pwd=models.CharField(max_length=32)
  email=models.EmailField()
  tel=models.CharField(max_length=32)

模板文件:register.html

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

</head>
<body>

<form action="" method="post">
  {% csrf_token %} 
  <div>
    <label for="user">用户名</label>
    <p><input type="text" name="name" id="name"></p>
  </div>
  <div>
    <label for="pwd">密码</label>
    <p><input type="password" name="pwd" id="pwd"></p>
  </div>
  <div>
    <label for="r_pwd">确认密码</label>
    <p><input type="password" name="r_pwd" id="r_pwd"></p>
  </div>
   <div>
    <label for="email">邮箱</label>
    <p><input type="text" name="email" id="email"></p>
  </div>
  <input type="submit">
</form>

</body>
</html>

视图函数:register

# forms组件
from django.forms import widgets

wid_01=widgets.TextInput(attrs={"class":"form-control"})
wid_02=widgets.PasswordInput(attrs={"class":"form-control"})

class UserForm(forms.Form):
  name=forms.CharField(max_length=32,
             widget=wid_01
             )
  pwd=forms.CharField(max_length=32,widget=wid_02)
  r_pwd=forms.CharField(max_length=32,widget=wid_02)
  email=forms.EmailField(widget=wid_01)
  tel=forms.CharField(max_length=32,widget=wid_01)

def register(request):

  if request.method=="POST":
    form=UserForm(request.POST)
    if form.is_valid():
      print(form.cleaned_data)    # 所有干净的字段以及对应的值
    else:
      print(form.cleaned_data)    #
      print(form.errors)       # ErrorDict : {"校验错误的字段":["错误信息",]}
      print(form.errors.get("name")) # ErrorList ["错误信息",]
    return HttpResponse("OK")
  form=UserForm()
  return render(request,"register.html",locals())

1. 渲染表单标签功能

渲染方式一

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <!-- 最新版本的 Bootstrap 核心 CSS 文件 -->
  <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="external nofollow" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
</head>
<body>
<h3>注册页面</h3>
<div class="container">
  <div class="row">
    <div class="col-md-6 col-lg-offset-3">

        <form action="" method="post">
          {% csrf_token %}
          <div>
            <label for="">用户名</label>
            {{ form.name }}
          </div>
          <div>
            <label for="">密码</label>
            {{ form.pwd }}
          </div>
          <div>
            <label for="">确认密码</label>
            {{ form.r_pwd }}
          </div>
          <div>
            <label for=""> 邮箱</label>
            {{ form.email }}
          </div>

          <input type="submit" class="btn btn-default pull-right">
        </form>
    </div>
  </div>
</div>
</body>
</html>

渲染方式二

<form action="" method="post">
          {% csrf_token %}

          {% for field in form %}
            <div>
              <label for="">{{ field.label }}</label>
              {{ field }}
            </div>
          {% endfor %}
          <input type="submit" class="btn btn-default pull-right">

</form>

渲染方式三

<form action="" method="post">
  {% csrf_token %}

  {{ form.as_p }}
  <input type="submit" class="btn btn-default pull-right">

</form>

2. 显示错误信息与重置输入值功能

视图代码

def register(request):

  if request.method=="POST":
    form=UserForm(request.POST)
    if form.is_valid():
      print(form.cleaned_data)    # 所有干净的字段以及对应的值
    else:
      print(form.cleaned_data)    #
      print(form.errors)       # ErrorDict : {"校验错误的字段":["错误信息",]}
      print(form.errors.get("name")) # ErrorList ["错误信息",]
    return render(request,"register.html",locals())
  form=UserForm()
  return render(request,"register.html",locals())

模板代码

<form action="" method="post" novalidate>
  {% csrf_token %}

  {% for field in form %}
    <div>
      <label for="">{{ field.label }}</label>
      {{ field }} <span class="pull-right" style="color: red">{{ field.errors.0 }}</span>
    </div>
  {% endfor %}
  <input type="submit" class="btn btn-default">

</form>

3. 局部钩子与全局钩子应用

模板代码

# forms组件
from django.forms import widgets

wid_01=widgets.TextInput(attrs={"class":"form-control"})
wid_02=widgets.PasswordInput(attrs={"class":"form-control"})

from django.core.exceptions import ValidationError
class UserForm(forms.Form):
  name=forms.CharField(max_length=32,
             widget=wid_01
             )
  pwd=forms.CharField(max_length=32,widget=wid_02)
  r_pwd=forms.CharField(max_length=32,widget=wid_02)
  email=forms.EmailField(widget=wid_01)
  tel=forms.CharField(max_length=32,widget=wid_01)

  # 局部钩子
  def clean_name(self):
    val=self.cleaned_data.get("name")
    if not val.isdigit():
      return val
    else:
      raise ValidationError("用户名不能是纯数字!")

  # 全局钩子

  def clean(self):
    pwd=self.cleaned_data.get("pwd")
    r_pwd=self.cleaned_data.get("r_pwd")

    if pwd==r_pwd:
      return self.cleaned_data
    else:
      raise ValidationError('两次密码不一致!')

def register(request):

  if request.method=="POST":
    form=UserForm(request.POST)
    if form.is_valid():
      print(form.cleaned_data)    # 所有干净的字段以及对应的值
    else:
      clean_error=form.errors.get("__all__")

    return render(request,"register.html",locals())
  form=UserForm()
  return render(request,"register.html",locals())

视图代码

<form action="" method="post" novalidate>
      {% csrf_token %}

      {% for field in form %}
        <div>
          <label for="">{{ field.label }}</label>
          {{ field }}
          <span class="pull-right" style="color: red">
             {% if field.label == 'R pwd' %}
             <span>{{ clean_error.0 }}</span>
             {% endif %}
             {{ field.errors.0 }}
          </span>
        </div>
      {% endfor %}
      <input type="submit" class="btn btn-default">

</form>

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