Django高级之forms组件
forms组件之校验字段
# 第一步：定义一个类,继承forms.Form # 第二步：在类中写字段，要校验的字段，字段属性就是校验规则 # 第三步：实例化得到一个Form对象，把要校验的数据传入 # 第四步：调用register_form.is_valid()校验，校验通过就是True # 第五步：校验通过有register_form.cleaned_data # 第六步：校验不通过 register_form.errors
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>注册用户</title> <script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.4.1/jquery.min.js"></script> <link href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/3.4.1/css/bootstrap.min.css" rel="stylesheet"> <script src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/3.4.1/js/bootstrap.min.js"></script> </head> <body> <div class="col-md-6 col-md-offset-3"> <div class="panel panel-primary"> <div class="panel-heading"> <h3 class="panel-title">注册功能</h3> </div> <div class="panel-body"> <h1 class="text-center">注册</h1> <form action="" method="post"> <p>用户名:<input type="text" name="name" class="form-control"></p> <p>密码:<input type="password" name="password" class="form-control"></p> <p>确认密码:<input type="password" name="re_password" class="form-control"></p> <p>邮箱:<input type="text" name="email" class="form-control"></p> <input id="id_btn" type="submit" class="btn btn-primary btn-block"> </div> </div> </div> </body> </html>
class User(models.Model): name = models.CharField(max_length=32,verbose_name='用户名') password = models.CharField(max_length=32,verbose_name='密码') email = models.EmailField(verbose_name='邮箱')
# views.py from django.shortcuts import render from django import forms #定义类 class RegisterForm(forms.Form): # name字符串类型最大8位，最小3位 name = forms.CharField(max_length=8, min_length=3, label='用户名') # password字符串类型最大8位，最小3位 password = forms.CharField(max_length=8, min_length=3, label='密码') # re_password字符串类型最大8位，最小3位 re_password = forms.CharField(max_length=8, min_length=3, label='确认密码') # email必须符合邮箱格式，xxx@xx.com email = forms.EmailField(label='邮箱') #在视图中使用 register_form = RegisterForm(request.POST) if register_form.is_valid(): # 校验通过，存 # 取出校验通过的数据 print('校验通过') print(register_form.cleaned_data) # 存储前先删除多余的字段 register_form.cleaned_data.pop('re_password') # 将数据存入数据库的user表中 models.User.objects.create(**register_form.cleaned_data) else: # 校验不通过 print('校验不通过') print(register_form.errors)
def register(request): if request.method == 'GET': # GET请求没有数据，需要生成一个空form对象 # 这个form跟下面没有关系，是get请求过来的得到一个空form register_form = RegisterFrom() # 传到前端页面后，通过form进行渲染 return render(request, 'register.html', {'form': register_form}) else: register_form = RegisterFrom(request.POST) if register_form.is_valid(): print('效验通过') print(register_form.cleaned_data) register_form.cleaned_data.pop('re_password') models.User.objects.create(**register_form.cleaned_data) else: print('效验不通过') print(register_form.errors) return render(request,'register.html')
<h2>通过form自动渲染一</h2> <form action="" method="post"> <p>用户名 {{ form.name }}</p> <p>密码 {{ form.password }}</p> <p>确认密码 {{ form.re_password }}</p> <p>邮箱 {{ form.email }}</p> <input type="submit" value="提交"></form>
渲染方式二
推荐使用，代码书写简单，并且可扩展性强
<h2>通过form自动渲染二(基本用这种)</h2> <form action="" method="post"> {% for item in form %} <p>{{ item.label }}{{ item }}</p> {% endfor %} <input type="submit" value="提交"><span style="color: red">{{ error }}</span> </form>
渲染方式三
代码书写极少，封装程度太高，不便于后续的扩展，一般情况下只在本地测试使用
<h2>通过form自动渲染三</h2> <form action="" method="post"> {{ form.as_p }} {# {{ form.as_table }}#} {# {{ form.as_ul }}#} </form>
前端渲染代码：（全部采用方式二）
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>注册页面</title> <script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.4.1/jquery.min.js"></script> <link href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/3.4.1/css/bootstrap.min.css" rel="stylesheet"> <script src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/3.4.1/js/bootstrap.min.js"></script> </head> <body> <div class="col-md-6 col-md-offset-3"> <div class="panel panel-primary"> <div class="panel-heading"> <h3 class="panel-title text-center"></h3> </div> <div class="panel-body"> <h1 class="text-center">注册</h1> <form action="" method="post" novalidate> {% for item in form %} <div class="form-group"> <p>{{ item.label }}{{ item }} <span style="color: red">{{ item.errors.0 }}</span></p> </div> {% endfor %} <input type="submit" value="提交" class="form-control"><span style="color: red">{{ error }}</span> </form> </div> </div> </div> </body> </html>
from django import forms from django.forms import widgets class RegisterForm(forms.Form): name = forms.CharField(max_length=8, min_length=3, label='用户名', error_messages={ 'max_length': '用户名最长为8位', 'min_length': '用户名最短为3位', 'required': '用户名不能为空位' }, widget=widgets.TextInput(attrs={'class':'form-control'})) password = forms.CharField(max_length=8, min_length=3, label='密码', error_messages={ 'max_length': '密码最长为8位', 'min_length': '密码最短为3位', 'required': '密码不能为空' }, widget=widgets.PasswordInput(attrs={'class':'form-control'})) re_password = forms.CharField(max_length=8, min_length=3, label='确认密码', error_messages={ 'max_length' : '密码最长为8位', 'min_length' : '密码最短为3位', 'required' : '密码不能为空' }, widget=widgets.PasswordInput(attrs={'class':'form-control'})) email = forms.EmailField(label='邮箱', error_messages={'required': '邮箱不能为空', 'invalid': '邮箱格式不正确'}, widget=widgets.TextInput(attrs={'class':'form-control'})) # views视图函数处理部分： def register(request): if request.method == 'GET': register_form = RegisterForm() return render(request, 'register.html', {'form': register_form}) else: register_form = RegisterForm(request.POST) if register_form.is_valid(): print('校验通过') print(register_form.cleaned_data) register_form.cleaned_data.pop('re_password') models.User.objects.create(**register_form.cleaned_data) return HttpResponse('ok') else: # 校验不通过 print('校验不通过') print(register_form.errors) return render(request, 'register.html', {'form': register_form})
forms组件参数配置
class Ret(Form): name = forms.CharField(max_length=10, min_length=2, label='用户名', error_messages={ 'required': '该字段不能为空', 'invalid': '格式错误', 'max_length': '太长', 'min_length': '太短'}, widget=widgets.TextInput(attrs={'class':'form-control'}))
-局部钩子 -def clean_字段名(self): -校验规则 -如果通过，return 值 -如果不通过，抛异常 -全局钩子（多个字段校验） -def clean(self): -如果通过，return clean_data -如果不通过，抛异常
局部钩子
def clean_name(self): # name字段的局部钩子 # 获取用户输入的用户名 name = self.cleaned_data.get('name') # 校验名字不能以sb开头 if name.startswith('sb'): # 校验不通过，必须抛异常， raise ValidationError('不能以sb开头') else: # 校验通过，再返回name对应的值 return name
全局钩子
def clean(self): # 全局钩子 password = self.cleaned_data.get('password') re_password = self.cleaned_data.get('re_password') if re_password != password: # 校验不通过 self.add_error('re_password','两次密码不一致') else: # 局部钩子拿什么返回什么，全局钩子所有都返回 return self.changed_data
-使用步骤： -写一个类，继承Form类 -写字段，字段参数（限制该字段的长短） -错误信息中文：字段参数 -widget：控制生成标签的属性 -视图函数中： -实例化得到form对象时，把要校验的数据传入 -is_valid():clean_data和errors就有值了 -如果校验通过就存，不通过就给页面提示 -渲染页面 -for循环的方式渲染页面（在标签前后可以再加标签）
from django.db import models # 创建用户表 class User(models.Model): name = models.CharField(max_length=32,verbose_name='用户名') password = models.CharField(max_length=32,verbose_name='密码') email = models.EmailField(verbose_name='邮箱')
from django.conf.urls import url from app01 import views urlpatterns = [ url(r'^register/$',views.register) ]
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>模板层注册页面</title> <script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.4.1/jquery.min.js"></script> <link href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/3.4.1/css/bootstrap.min.css" rel="stylesheet"> <script src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/3.4.1/js/bootstrap.min.js"></script> </head> <body> <div class="container-fluid"> <div class="row"> <div class="col-md-6 col-md-offset-3"> <div class="panel panel-primary"> <div class="panel-heading"> <h3 class="panel-title text-center"></h3> </div> <div class="panel-body"> <h1 class="text-center">注册</h1> <form action="" method="post" novalidate> {% for item in form %} <div class="form-group"> <p>{{ item.label }}{{ item }} <span style="color: red">{{ item.errors.0 }}</span></p> </div> {% endfor %} <input type="submit" value="提交" class="btn btn-primary btn-block"><span style="color: red">{{ error }}</span> </form> </div> </div> </div> </div> </div> </body> </html>
from django import forms from django.forms import widgets from django.core.exceptions import ValidationError class RegisterForm(forms.Form): name = forms.CharField(max_length=8, min_length=3, label='用户名', error_messages={ 'max_length': '用户名最长为8位', 'min_length': '用户名最短为3位', 'required': '用户名不能为空位' }, widget=widgets.TextInput(attrs={ 'class':'form-control' })) password = forms.CharField(max_length=8, min_length=3, label='密码', error_messages={ 'max_length': '密码最长为8位', 'min_length': '密码最短为3位', 'required': '密码不能为空' }, widget=widgets.PasswordInput(attrs={ 'class':'form-control' })) re_password = forms.CharField(max_length=8, min_length=3, label='确认密码', error_messages={ 'max_length' : '密码最长为8位', 'min_length' : '密码最短为3位', 'required' : '密码不能为空' }, widget=widgets.PasswordInput(attrs={ 'class':'form-control' })) email = forms.EmailField(label='邮箱', error_messages={ 'required': '邮箱不能为空', 'invalid': '邮箱格式不正确' }, widget=widgets.TextInput(attrs={ 'class':'form-control' def clean_name(self): # name字段的局部钩子 # 获取用户输入的用户名 name = self.cleaned_data.get('name') # 校验名字不能以sb开头 if name.startswith('sb'): # 校验不通过，必须抛异常， raise ValidationError('不能以sb开头') else: # 校验通过，再返回name对应的值 return name def clean(self): # 全局钩子 password = self.cleaned_data.get('password') re_password = self.cleaned_data.get('re_password') if re_password != password: # 校验不通过 self.add_error('re_password','两次密码不一致') else: # 局部钩子拿什么返回什么，全局钩子所有都返回 return self.changed_data from app01 import models def register(request): if request.method == 'GET': # GET请求没有数据，需要生成一个空form对象 # 这个form跟下面没有关系，是get请求过来的得到一个空form register_form = RegisterFrom() # 传到前端页面后，通过form进行渲染 return render(request, 'register.html', {'form': register_form}) else: # 实例化得到对象，传入要校验的数据 register_form = RegisterForm(request.POST) if register_form.is_valid(): # 校验通过，存 # 取出校验通过的数据 print('校验通过') print(register_form.cleaned_data) register_form.cleaned_data.pop('re_password') models.User.objects.create(**register_form.cleaned_data) return HttpResponse('ok') else: # 校验不通过 print('校验不通过') print(register_form.errors) return render(request, 'register.html', {'form': register_form})
1 为什么局部钩子要写成 clean_字段名，为什么要抛异常 2 入口在 is_valid() 3 校验流程 -先校验字段自己的规则（最大，最小，是否必填，是不是合法） -校验局部钩子函数 -全局钩子校验 4 流程 is_valid()---》return self.is_bound and not self.errors self.errors：方法包装成了数据数据 一旦self._errors有值，就不进行校验了（之前调用过了） self.full_clean()：核心 self._errors = ErrorDict() if not self.is_bound: return self.cleaned_data = {} self._clean_fields() self._clean_form() self._post_clean() self._clean_fields()：核心代码,局部钩子执行位置 value = field.clean(value)# 字段自己的校验规则 self.cleaned_data[name] = value #把校验后数据放到cleaned_data if hasattr(self, 'clean_%s' % name): # 判断有没有局部钩子 value = getattr(self, 'clean_%s' % name)() #执行局部钩子 self.cleaned_data[name] = value #校验通过，把数据替换一下 # 如果 校验不通过，会抛异常，会被捕获，捕获后执行 self.add_error(name, e) def _clean_form(self):#全局钩子执行位置 def _clean_form(self): try: #如果自己定义的form类中写了clean，他就会执行 cleaned_data = self.clean() except ValidationError as e: self.add_error(None, e)
from django.urls import path from app01 import views urlpatterns = [ path('user/add/', views.user_add), ]
from django.shortcuts import render, redirect, HttpResponse from app01.models import Department, UserInfo from django import forms # 自定义一个类，继承ModelForm类 class UserModelForm(forms.ModelForm): class Meta: model = UserInfo # 对应model中的类 fields = ["name", "password", "age", "account", "create_time", "gender", "depart"] # fields = ['字段1','字段2',...] 或者这种用法，把需要展示的字段添加到这个列表中 # fields = '__all__' # 获取所有字段 # 根据源码重写父类方法 def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) # 循环找到所有字段的插件，添加class = "form-control" for name, field in self.fields.items(): # 不想让某个字段用样式可以做判断 # if name == "password": # continue field.widget.attrs = {"class": "form-control"} # 可以自定义属性 def user_add(request): user_data = UserModelForm() # 然后在url对应的视图函数中实例化这个类，把这个对象传给前端 return render(request, 'user_add.html', {"user_data": user_data})
{% load static %}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<link rel="stylesheet" href="{% static 'bootstrap-3.4.1-dist/css/bootstrap.css' %}">
<script src="{% static 'js/jQuery3.6.js' %}"></script>
<script src="{% static 'bootstrap-3.4.1-dist/js/bootstrap.js' %}"></script>
</head>
<body>
<div class="container">
<div class="row">
<div class="col-md-8 col-md-offset-2">
<div class="panel panel-default">
<div class="panel-heading">
<h2 class="panel-title text-center">
<span class="glyphicon glyphicon-plus"></span>
添加用户
</h2>
</div>
<div class="panel-body">
<form method="post">
{% csrf_token %}
{% for obj in user_data %}
<div class="form-group">
<label>{{ obj.label }}</label>
{{ obj }}
</div>
{% endfor %}
<button type="submit" class="btn btn-primary btn-block">添 加</button>
</form>
</div>
</div>
</div>
</div>
</div>
</body>
</html>
from django.db import models class Department(models.Model): title = models.CharField(max_length=64, verbose_name="部门名称") def __str__(self): return self.title class UserInfo(models.Model): name = models.CharField(max_length=32, verbose_name="姓名") password = models.CharField(max_length=64, verbose_name="密码") age = models.IntegerField(verbose_name="年龄") account = models.DecimalField(max_digits=10, decimal_places=2, default=0, verbose_name="账户余额") create_time = models.DateTimeField(verbose_name="入职时间") # 级联删除 depart = models.ForeignKey(to="Department", to_field="id", on_delete=models.CASCADE, verbose_name="部门") gender_choices = ( (1, "男"), (2, "女") ) gender = models.SmallIntegerField(choices=gender_choices, verbose_name="性别")
从来就没有正确的选择，我们只不过是要努力奋斗，使当初的选择变得正确。
