base知识
参考博文：https://www.cnblogs.com/yuanchenqi/articles/9036474.html
用户表单是Web端的一项基本功能,大而全的Django框架中自然带有现成的基础form对象,Python的Django框架中forms表单类的使用方法详解
1，demo1
form表单的那么属性值对应UserForm属性值
class UserForm(forms.Form):
name=forms.CharField(min_length=4)
pwd=forms.CharField(min_length=4)
form=UserForm({"name":"yuan","email":"123"})
print(form.is_valid()) # 返回布尔值
2，form渲染组件
{{ form.name }}
Form表单的功能
- 自动生成HTML表单元素
- 检查表单数据的合法性
- 如果验证错误，重新显示表单（数据不会重置）
- 数据类型转换（字符类型的数据转换成相应的Python类型）
Form相关的对象包括
- Widget：用来渲染成HTML元素的工具，如：forms.Textarea对应HTML中的<textarea>标签
- Field：Form对象中的一个字段，如：EmailField表示email字段，如果这个字段不是有效的email格式，就会产生错误。
- Form：一系列Field对象的集合，负责验证和显示HTML元素
- Form Media：用来渲染表单的CSS和JavaScript资源。
forms里面的字段：
required：是否可以为空。required=True 不可以为空，required=False 可以为空 max_length=4 最多4个值，超过不会显示 min_length=2 至少两个值，少于两个会返回提示信息 error_messages={'required': '邮箱不能为空', 'invalid': '邮箱格式错误'} 自定义错误信息，invalid 是格式错误 widget=forms.TextInput(attrs={'class': 'c1'}) 给自动生成的input标签自定义class属性 widget=forms.Textarea() 生成Textarea标签。widget默认生成input标签
校验字段功能
精简示例：
form表单校验字段 from django import forms class UserForm(forms.Form): name=forms.CharField(min_length=4,label="用户名") pwd=forms.CharField(min_length=4) r_pwd=forms.CharField(min_length=4) email=forms.EmailField() tel=forms.CharField() class reg(request): if request.method=="POST": # form=UserForm({"name":"yuan","email":"123"}) form=UserForm(request.POST) print(form.is_valid()) if form.is_valid(): print(form.cleaned_data) else: print(form.cleaned_data) # 正确的键值对 print(form.errors) # 错误的键：错误的信息 return HttpResponse("ok") return render(request,"reg.html")
针对一个实例：注册用户讲解。
模型：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: 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())
渲染标签功能
精简示例：
渲染标签 方式1 form=UserForm() return render(request,"reg.html",locals()) <p>用户名：{{form.name}}</p> <p>{{form.name.label}}：{{form.name}}</p> 方式2 {% csrf_token %} {% for field in form %} <div> <label for="">{{field.label}}</label> {{field}} </div> {% endfor %} 方式3 # 了解，不建议使用 {% csrf_token %} {{form as_p}}
渲染方式1
<!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" 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2
<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3
<form action="" method="post"> {% csrf_token %} {{ form.as_p }} <input type="submit" class="btn btn-default pull-right"> </form>
显示错误与重置输入信息功能
精简示例：
渲染错误信息 <p>{{form.name.label}}：{{form.name}}<span>{{form.name.errors.0}}</span></p> forms组件的参数配置 from django.forms import widgets name=forms.CharField(min_length=4,label="用户名",error_message={"required":"该字段不能为空"}) pwd=forms.CharField(min_length=4,label="密码",widgets=widgets.PasswordInput(attrs={"class":"form-control"})) email=forms.EmailField(label="邮箱",error_message={"required":"该字段不能为空","invalid":"格式错误"})
视图
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
<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>
局部钩子与全局钩子
精简示例：
钩子 from django.core.exceptions import ValidationError def clean_name(self): val = self.cleaned_data.get("name") ret = UserInfo.objects.filter(name=val) if not ret: return val else: raise ValidationError("该用户已经注册！") 全局钩子 def clean(self): pwd = self.cleaned_data.get("pwd") r_pwd = self.cleaned_data.get("r_pwd") if pwd and r_pwd: # 都不为空 if pwd == r_pwd: return self.cleaned_data else: raise ValidationError("俩次密码不一致") else: return self.cleaned_data 全局错误 print("error",form.errors.get("__all__")[0]) errors = form.errors.get("__all__") return render(request,"reg.html",locals()) <p>{{form.name.label}}：{{form.name}}<span class="pull-right error">{{form.name.errors.0}}</span></p>
模板
# 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
<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>