forms组件
forms组件，是一个类。在视图函数中创建一个类,类需要继承forms.Form
from django import forms
1.校验数据
步骤和语法：
1. 创建一个forms类，该类需继承forms.Form , 得到一个类（假设为EmpForm），用于校正数据
2.把用户信息传给ef=EmpForm(request.POST),得到一个form对象ef（传入的数据必须为字典）
3. ef.is_valid() ,数据都合格为True ,否则为False
4.ef.is_valid()之后可以获取两部分数据：
ef.cleand_data 获取合格后的数据，为字典
ef.errors 不合格数据以及错误信息
model.py 文件中：
from django.db import models # Create your models here. class Emp(models.Model):
name =models.CharField(max_length=32) #后面跟的是约束对象
age =models.IntegerField()
salary =models.DecimalField(max_digits=8,decimal_places=2)
视图函数中：
from django.shortcuts import render,HttpResponse,redirect
from aap1 import models
# Create your views here.
from django import forms
#forms 组件是一个类，对数据进行校正，下面是分别对name，age 字段进行较正
class EmpForm(forms.Form):
#且所有要校正的字段必须为非空，否则会报错
name = forms.CharField(max_length=5) #name需要校验的字段 ，forms. 后面跟的是规则对象，此处为CharField()
age = forms.IntegerField() #此校验规则，必须为一个数字 def addemp(request): if request.method=="GET":
return render(request,"add.html") else:
#获取字段值
# name =request.POST.get("name")
# age =request.POST.get("age")
# salary =request.POST.get("salary")
# # 类 ,操作简单，耦合性比较好
ef = EmpForm(request.POST) #得到一个form对象
if ef.is_valid():
print(ef.cleaned_data) #得到校正合格之后的数据，也是一个字典
models.Emp.objects.create(**ef.cleaned_data) #传入一个字典，但是这样创建的话，需要将Emp中所有字段都进行校验或默认
else:
print(ef.errors) #得到错误信息字典
return HttpResponse("ok")
2.渲染页面
models.py文件中： from django.db import models # Create your models here. class Emp(models.Model):
name =models.CharField(max_length=32) #后面跟的是约束对象
age =models.IntegerField()
salary =models.DecimalField(max_digits=8,decimal_places=2)
#后端views.py 文件中：（form组件的构建） from django import forms
from django.core.exceptions import ValidationError
#forms 组件是一个类，创建一个需要渲染或检验的form组件
class EmpForm(forms.Form):
#且所有要校正的字段必须为非空，否则会报错
name = forms.CharField(max_length=5,label="姓名",error_messages={"required":"该字段不能为空"}) #name需要校验的字段 ，forms. 后面跟的是规则对象，此处为CharField()
age = forms.IntegerField(label="年龄") #此校验规则，必须为一个数字
salary=forms.CharField(label="薪水")
#视图函数，
def addemp(request): if request.method=="GET":
form =EmpForm()
return render(request,"add.html",locals()) # locals(),将form 中所有的字段都可以传给前端页面进行渲染 else:
#post请求得到，request.post 接收到前端传来的数据中的key必须和form组件中的字段名一样，不然无法进行校正，也就不能像下面一样传值
form = EmpForm(request.POST) #得到一个form对象
if form.is_valid(): #校正通过
print(form.cleaned_data) #得到干净的数据
models.Emp.objects.create(**form.cleaned_data) #数据干净后创建员工
return HttpResponse("添加成功")
else:
#校正没通过后向前端显示错误信息
print(form.errors)
return render(request,"add.html",{"form":form})
渲染方式一：
<h3>渲染方式1</h3>
<form action="">
{% csrf_token %}
{{ form.as_p }} #
<input type="submit">
</form>
渲染后：
<h3>渲染方式1</h3>
<form action="">
<input type="hidden" name="csrfmiddlewaretoken" value="85HSKETnbwtkVgBId2g0eZ0GFmGoYqZ2oPcvdUQmupCH8hiWPFRWMsoXw7EV9YEb">
<p><label for="id_name">姓名:</label> <input type="text" name="name" maxlength="5" required id="id_name"></p>
<p><label for="id_age">年龄:</label> <input type="number" name="age" required id="id_age"></p>
<p><label for="id_salary">薪水:</label> <input type="text" name="salary" required id="id_salary"></p>
<input type="submit">
</form>
页面效果：
渲染方式二：
前端代码：
<h3>渲染方式2</h3>
<form action="">
{% csrf_token %}
<div>
<label for="">姓名</label>
{{ form.name }}
</div>
<div>
<label for="">年龄</label>
{{ form.age }}
</div>
<div>
<label for="">薪水</label>
{{ form.salary }}
</div> <input type="submit">
</form>
渲染后：
<h3>渲染方式2</h3>
<form action="">
<input type="hidden" name="csrfmiddlewaretoken" value="85HSKETnbwtkVgBId2g0eZ0GFmGoYqZ2oPcvdUQmupCH8hiWPFRWMsoXw7EV9YEb">
<div>
<label for="">姓名</label>
<input type="text" name="name" maxlength="5" required id="id_name">
</div>
<div>
<label for="">年龄</label>
<input type="number" name="age" required id="id_age">
</div>
<div>
<label for="">薪水</label>
<input type="text" name="salary" required id="id_salary">
</div> <input type="submit">
</form>
页面效果：
渲染方式三：
<h3>渲染方式3</h3>
<form action="" method="post" novalidate>
{% csrf_token %}
{% for flied in form %}
<div>
<label for="">{{ flied.label }}</label>
{{ flied }} <span>{{ flied.errors.0 }}</span>
</div>
{% endfor %}
<input type="submit">
</form>
渲染后：
<h3>渲染方式3</h3>
<form action="" method="post" novalidate>
<input type="hidden" name="csrfmiddlewaretoken" value="85HSKETnbwtkVgBId2g0eZ0GFmGoYqZ2oPcvdUQmupCH8hiWPFRWMsoXw7EV9YEb"> <div>
<label for="">姓名</label>
<input type="text" name="name" maxlength="5" required id="id_name"> <span></span>
</div> <div>
<label for="">年龄</label>
<input type="number" name="age" required id="id_age"> <span></span>
</div> <div>
<label for="">薪水</label>
<input type="text" name="salary" required id="id_salary"> <span></span>
</div> <input type="submit">
</form>
效果图：
3.显示错误与重置输入信息功能
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>
4.局部钩子与全局钩子
视图
# 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())
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">
{% 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>
forms组件知识补充：
model用法：
gender=models.IntegerField(choices=((1,"男"),(2,"女")),default=1)
alex=Author.objects.all().first()
alex.gender #
alex.get_gender_display() # "男" forms用法：
# Create your models here.
class Book(models.Model):
title = models.CharField( max_length=32)
pub_date=models.DateField()
price=models.DecimalField(max_digits=5,decimal_places=2)
state=models.IntegerField(choices=((1,"已出版"),(2,"未出版")),default=1)
publish=models.ForeignKey(to="Publish",to_field="id",on_delete=models.CASCADE,null=True)
authors=models.ManyToManyField("Author",db_table="book2authors") # 创建关系表
def __str__(self):
return self.title # forms组件：
from django import forms
class BookForm(forms.Form):
title=forms.CharField(max_length=32)
price=forms.DecimalField(max_digits=5,decimal_places=2)
pub_date=forms.DateField()
state=forms.ChoiceField(choices=((1,"已出版"),(2,"未出版"))) #在前端的的效果 <option value=1>已出版<option> <option value=2>未出版<option>
# publish=forms.ChoiceField(choices=list(models.Publish.objects.all().values_list("pk","name")))
publish=forms.ModelChoiceField(queryset=models.Publish.objects.all())
authors=forms.ModelMultipleChoiceField(queryset=models.Author.objects.all()) # modelForm
class BookModelForm(forms.ModelForm):
class Meta:
model=models.Book
# fields=["title","price"]
# exclude = ["title"]
fields="__all__" #ModelForm 参数配置 class BookModelForm(forms.ModelForm):
class Meta:
model=models.Book
# fields=["title","price"]
# exclude = ["title"]
fields="__all__" #定义标签属性
widgets={
"title":wid.TextInput(attrs={"class":"form-control"}),
"price":wid.TextInput(attrs={"class":"form-control"})
}
error_messages={
"title":{"required":"该字段不能为空"}
}
labels={
"title":"书籍名称"
} def clean_title(self):
val=self.cleaned_data.get("title")
if val.startswith("yuan"):
return val
else:
raise ValidationError("必须以yuan开头！")